# I just received a quotation for LiFePO at 0.35/wh



## Technologic (Jul 20, 2008)

I'm wondering if it's legit.

It seems very legit to me... the largest manfacturer that uses the shenzhen port.

3.2v (nominal) x 90AH for $99USD + shipping each unit. or 35 cents per watt hour.

they also have a low voltage/high voltage cut off BMS and a charger.

testing will happen once sample arrives in a week.. .I've already T/T'd the money.

Name will be given ONCE it arrives... I don't want people blowing money besides me if I can help it... possible group buy offerings to come (tacking on a possible 150 piece order myself for 3 cars)


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## TheSGC (Nov 15, 2007)

I really wonder if this is finally the age of the EV and affordable batteries. I have gotten a few quotes of LiFePO over the past year, and the price of the second quote was less than half of the first quote 11 months before.

Hopefully you will have some decent testing with these and provide us with pictures!


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## Technologic (Jul 20, 2008)

TheSGC said:


> I really wonder if this is finally the age of the EV and affordable batteries. I have gotten a few quotes of LiFePO over the past year, and the price of the second quote was less than half of the first quote 11 months before.
> 
> Hopefully you will have some decent testing with these and provide us with pictures!


$1.1USD/AH is the absolute lowest I've ever seen.... ever for a 3.2v prismatic battery.

I was provided with so much information and so many pictures of their shipping warehouse, so many positive reviews from alibaba about this company.

I'm quite sure it's legitimate... but I don't want people busting up to this company asking for samples at this price or whatever until I confirm their legitimacy and cycle life myself.

I will start a new thread once the sample 3.2vx90AH battery arrives.


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## ElectriCar (Jun 15, 2008)

Who are the reviews from on Alibaba and are there a lot of them? Reviews are usually a big factor with me. I always wonder though if they have a batch they send out for people who want to sample and large orders may be who knows what. You're not talking beans even at .35/ah. 

David85 BTW ordered his at 50c/ah. So you've gotten a 30% discount over his. I bet he's going to be sick if this is legit. I can't wait until it's affordable. My S10's acceleration is awesome even with 1500 lbs of lead when it's at 90-100% charge. 

I'm sure you'll keep us up to date. Best of luck.


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## Technologic (Jul 20, 2008)

ElectriCar said:


> Who are the reviews from on Alibaba and are there a lot of them? Reviews are usually a big factor with me. I always wonder though if they have a batch they send out for people who want to sample and large orders may be who knows what. You're not talking beans even at .35/ah.
> 
> David85 BTW ordered his at 50c/ah. So you've gotten a 30% discount over his. I bet he's going to be sick if this is legit. I can't wait until it's affordable. My S10's acceleration is awesome even with 1500 lbs of lead when it's at 90-100% charge.
> 
> I'm sure you'll keep us up to date. Best of luck.


a sample really is peanuts... it's a mere $170 test ... which for this kind of possibility I'll take it.

I mean this would drop my budget and all subsequent clones of my custom 700 lb ish ultra high range car to something like $9000 fully built (including labor)... all of which is tax deductiable.

600,000 miles off 1 battery pack?

I have tons of data sheets from this place... and the lady was definitely not overly anxious to give me a price or talk to me at all... she talked more about the snow there.


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## ElectriCar (Jun 15, 2008)

You're aware of and it's not China HiPower correct? There's a post here about a group placing a big order and they got hosed with nearly a year delay and poor quality cells.


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## Technologic (Jul 20, 2008)

ElectriCar said:


> You're aware of and it's not China HiPower correct? There's a post here about a group placing a big order and they got hosed with nearly a year delay and poor quality cells.


It's not hipower... I believe it's thundersky (maybe)... but I can't confirm yet.

The BMS offers a high voltage/low voltage cutoff that is matched precisely to the battery they use (so it cuts off discharging at 2.5v and overcharging at 3.9v)

The BMS charger is way cheaper than David's... way way cheaper (a mere $350 for both).

3.2v nominal battery specs are posted right there.

I really prefer not to give out any additional company information until it at least arrives... I don't want people losing money if even the sample is a scam.

to be clear I've contacted every single Ni-MH and LiFePO battery producer in china that's information is available at all. This is the lowest price I've received...

I will be doing rigorous and mind blowingly annoying testing on this cell probably for 100 cycles before I'm prepared to order.


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## booksix (Aug 26, 2008)

Wow! Excited, I'm subscribing but please be sure to let us know in this thread when the new thread is started!


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## RKM (Jun 9, 2008)

Technologic,

Another very promising lead for LFP cells. Thanks for pursuing. The price is very attractive and I hope is legit this time . We've been down this road before.

The specs look very much like TS cells. Do they have 160Ah available?

Can you explain the "standard charge/discharge rate of .3CA"? Is this the rate upon which the cycles are based? I.E. 2000 cycles at 70% DOD, while pulling only .3CA?? I haven't been clear on this figure.

Thanks.

Rob


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## Technologic (Jul 20, 2008)

RKM said:


> Technologic,
> 
> Another very promising lead for LFP cells. Thanks for pursuing. The price is very attractive and I hope is legit this time . We've been down this road before.
> 
> The specs look very much like TS cells. Do they have 160Ah available?


 yes they do


> Can you explain the "standard charge/discharge rate of .3CA"? Is this the rate upon which the cycles are based? I.E. 2000 cycles at 70% DOD, while pulling only .3CA?? I haven't been clear on this figure.
> 
> Thanks.
> 
> Rob


That confused me as well, but I was told 3CA was the normal discharge rate... and 10CA was the maximum.


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## ElectriCar (Jun 15, 2008)

I saw some company who's info was 3C is normal, 10C is the 10 second rating, plenty enough to accelerate from a stop quickly.


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## Technologic (Jul 20, 2008)

ElectriCar said:


> I saw some company who's info was 3C is normal, 10C is the 10 second rating, plenty enough to accelerate from a stop quickly.


I think the C rating is fine on this (for most applications, but especially in my lightweight vehicle plans)... but I'll be testing that part also.

The advantage here is that this is the same price as buying a sufficient amount of trojan flooded LA batteries, for 8 times greater cycle life and 10 times lighter weight 

In fact the trojan 6V 210AH battery that costs $225, weighs 25kg has half of that as useable capacity meaning... this single lithium cell I ordered for $170 shipped (3.2vx90AH) for sampling ($99 in any quantity) has double the capacity per dollar than the trojan 6V

talk about your bad purchasing decisions  Lead Acid is dead my friends

My pack for 9.2KWH will cost me a mere $3200, last 600,000 miles in my car (thereabouts), and weigh a mere 200 lbs.... talk about sinful, hope everyone is ready for these facts if this proves legitimate.


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## Technologic (Jul 20, 2008)

My rough guesstimates on value per mile after this is built (assumed range of 200 miles per charge is a safe bet, though I expect closer to 300 miles, given the weight/CD of what I intend to build):
Access to electricity to charge (free at home, free at grad school): Nothing
Let's just assume 1500 cycles on the low side of things: Cost of batteries $3500 shipped

Means I could see 300k miles out of those batteries fairly safely:
0.011USD/mile

Let's assume the price of the car is discluded since everyone who does "gas estimates" seems to forget about oil changes, the price of their honda civic (my hand built endeavour will be far far cheaper than any car), things breaking down, new clutches, the fact that BMW seems to be incapable of making a proper air intake, etc.

And people say gas is cheaper even now.... *rubs forehead*
I think I will enjoy rubbing their faces in the truth personally later this year.

Price if you include the batteries (which I still find unfair when comparing electric vs gas) is still 5 times cheaper than driving a 32mpg civic at current gas prices.

And my car will only have 3 possible failure points (under normal wear... not just aches and pains from hundreds of thousands of miles on a car body). Charger/controller, Batteries, or motor... electronic systems should last a million or miles.


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## ElectriCar (Jun 15, 2008)

Technologic said:


> I think the C rating is fine on this (for most applications, but especially in my lightweight vehicle plans)... but I'll be testing that part also.
> 
> The advantage here is that this is the same price as buying a sufficient amount of trojan flooded LA batteries, for 8 times greater cycle life and 10 times lighter weight
> 
> ...


 I have about $2100 in my pack which is about 19kw after peukert. It's 1500 lbs of lead and you know it's there when you drive! Voltage sag is horrible in cool weather even when at full charge the voltage sags from 160ish to 140ish when accelerating. As the charge dissipates to around 144 the sag drops to closer to 100V or lower if I hammer it. 

Dude I can't wait to find out what this battery has to offer. I've even wondered about replacing my pack a portion at a time in a year or so. I do want to get some money back from this pack as long as it's performance is ok though before I start spending again! 

I'm also wanting to do a full size van later weighing probably 4000lbs plus the pack weight. But deleting a V8 and tranny it should still weigh less than the original setup depending on the Li pack size.


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## Technologic (Jul 20, 2008)

ElectriCar said:


> I have about $2100 in my pack which is about 19kw after peukert


(LA can't be safely taken below 50%... so half that number).


> It's 1500 lbs of lead and you know it's there when you drive! Voltage sag is horrible in cool weather even when at full charge the voltage sags from 160ish to 140ish when accelerating. As the charge dissipates to around 144 the sag drops to closer to 100V or lower if I hammer it.
> Dude I can't wait to find out what this battery has to offer. I've even wondered about replacing my pack a portion at a time in a year or so. I do want to get some money back from this pack as long as it's performance is ok though before I start spending again!
> I'm also wanting to do a full size van later weighing probably 4000lbs plus the pack weight. But deleting a V8 and tranny it should still weigh less than the original setup depending on the Li pack size.


Well I expect good results... I have fairly high expectations/standards for how long this will have to last.

But their information/pictures/case specifics (btw cases are free... like stacking them into packs... they will do that for free and wire it all up)


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## booksix (Aug 26, 2008)

free cases and wiring? Wow, who chooses the layout? Will they wire up the bms also?


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## Technologic (Jul 20, 2008)

booksix said:


> free cases and wiring? Wow, who chooses the layout?


 You can choose what cases and what configuration with your order I assume


> Will they wire up the bms also?


Yes they will... I attached a picture of the BMS/wiring thing they offer... I don't know if this case is more expensive. The normal setup is long threaded rods and terminals attached, this seems more mobile and more "custom"


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## booksix (Aug 26, 2008)

Yeah, I actually don't care for it. Don't need all the extra crap in my car. I want a 'case' just barely heavy-duty enough to contain my cells and keep them in shape and no more. I'd probably just opted for a homemade battery box. Any pics of the "long thread rods" setup? What I'm picturing is too weak and would allow cells to bulge...

As for the BMS, is it managing charging or only monitoring? And, the pic only shows single connections on either side of seven cells. Should it tap into each?

Also, you said roughly $99 for a 90ah unit, any idea how much for the 160? Still about $1 per ah?


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## Technologic (Jul 20, 2008)

booksix said:


> As for the BMS, is it managing charging or only monitoring? And, the pic only shows single connections on either side of seven cells. Should it tap into each?
> 
> Also, you said roughly $99 for a 90ah unit, any idea how much for the 160? Still about $1 per ah?


probably about $1.1 or $1.15/AH for the 160AH... they said it was their "second most commonly produced" size... 90AH being #1.

Series goes + to - and - to + so I assume that pack is in series.

Charger and BMS are seperate units... that "talk to each other" ... well at least the BMS can halt charging at 3.9v nominal.


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## booksix (Aug 26, 2008)

Ok, good to know. I'm liking the idea of two parallel 90 ah packs anyway 

Yes, it does look like they are in series, so, to optimally balance each cell the bms should connect to each. What am I missing?


edit: is the bms just not in the picture? Maybe I'm seeing a charger cable on each end? Also, do you know if the bms has a serial port? How about software for monitoring from a carPC? (not important I guess, just curious)


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## Technologic (Jul 20, 2008)

booksix said:


> edit: is the bms just not in the picture? Maybe I'm seeing a charger cable on each end? Also, do you know if the bms has a serial port? How about software for monitoring from a carPC? (not important I guess, just curious)


It has a data port, but I'm not sure what it can hook up to.

BMS is in the top lid of that case...


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## booksix (Aug 26, 2008)

Ok, so that is the bms. So, what am I missing? I still don't get what is does if it doesn't connect to each individual cell...


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## Technologic (Jul 20, 2008)

booksix said:


> Ok, so that is the bms. So, what am I missing? I still don't get what is does if it doesn't connect to each individual cell...


It monitors the cell voltages during charging and discharging... keeping them above nominal "averaged" for the pack.... this is how "most" BMS's work.... 
Thouch a circuit on each cell would be nice... it's not realistic price wise for something premade.

BMS also had a temp sensor for the batteries.


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## JRP3 (Mar 7, 2008)

Technologic said:


> It's not hipower... I believe it's thundersky (maybe)... but I can't confirm yet.


 I thought TS listed 3C continuous and 5C max, plus I've never seen them use the blue tops, though I'm sure that could change.


> The BMS offers a high voltage/low voltage cutoff that is matched precisely to the battery they use (so it cuts off discharging at 2.5v and overcharging at 3.9v)


I don't see from the picture how they can monitor and limit single cells with only 2 wires  If they are averaging the pack or part of the pack that doesn't really balance or protect.


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## Technologic (Jul 20, 2008)

JRP3 said:


> I thought TS listed 3C continuous and 5C max, plus I've never seen them use the blue tops, though I'm sure that could change.
> I don't see from the picture how they can monitor and limit single cells with only 2 wires  If they are averaging the pack or part of the pack that doesn't really balance or protect.


it monitors the pack, sort of how most Lifepo is handled... I wish it was per cell but that doesn't seem so likely to find at this point. The spec sheet shows 3C continuous... not sure... they have two different types of batteries to choose from.

It does balance quite a bit, and it's the best one can expect given the situation at hand with horrific BMS choices. The number of BMS's one can find right now that can monitor each cell can be counted on 1 hand... and are over $1200.

for that price any joe blow can throw an undervoltage/overvoltage cutoff on each cell and then do a BMS contected to the battery charger to cycle the switches on and off...

once the cells are balanced they shouldn't be coming out of balance that much.

Ideally you're right though... but you aren't going to find a BMS for 30 cells without custom making one.

Sadly, and very ironically, the simpliest part of any system should be the BMS (undervoltage/overvoltage and a switch linked to a charger) but it's the most difficult to find.


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## TheSGC (Nov 15, 2007)

I'll add my $0.02-

To the best of my knowledge NO ONE has a true Battery Management System. The only way that is possible is if EACH cell has a Contactor/Relay setup designed to cut off the cell from the rest of the system if it has problems (high voltage, low voltage, excessive amps, etc.) This would be a very expensive and complex system that I have never seen in production, only on paper in my notebook. 

Everything that exists out there only Monitors the cells and gives a warning, probably too late to actually do anything. When ever you see BMS, think Battery Monitoring System.

So if it comes with little wires the best it could do is stop the charger and give you messages. It WILL NOT stop low voltage or excessive AMP draw.


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## Technologic (Jul 20, 2008)

TheSGC said:


> I'll add my $0.02-
> 
> To the best of my knowledge NO ONE has a true Battery Management System. The only way that is possible is if EACH cell has a Contactor/Relay setup designed to cut off the cell from the rest of the system if it has problems (high voltage, low voltage, excessive amps, etc.) This would be a very expensive and complex system that I have never seen in production, only on paper in my notebook.
> .


It wouldn't be that expensive necessarily... you could do that all digitally, reading and monitoring the cell's voltage in real time... then stopping the charging system/discharging if anything goes wrong or if a cell drops suddenly into dangerously low voltage.

That's just a stop gap measure though... and MOST people in the marketplace would have to take it to a mechanic at that point.... even if the problem is simple.


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## booksix (Aug 26, 2008)

I guess I'm just wondering what it has and how it compares to what people are currently using.


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## Technologic (Jul 20, 2008)

booksix said:


> I guess I'm just wondering what it has and how it compares to what people are currently using.


most lifepo BMS/chargers are often together in the same package... the BMS for this detects cell temp, overall voltage during discharge and charging and stops the charging/discharging accordingly... not 100% ideal, but should work close to ideal (only thing better is monitoring each cell individually).

Most BMS's people use are either self monitoring voltage meters... or simply BMS/chargers all in one that only stop charging at a certain voltage.


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## booksix (Aug 26, 2008)

I see. thanks


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## david85 (Nov 12, 2007)

Technologic, I got your PM. Thanks for the heads up on your latest exploit. 

It sounds too good to be true, but I think it is possible. As I said before, the cost of batteries are still falling and with the drop in gas prices combined with an economic slowdown being felt in china, its not inconceivable that prices could be dropped as much has this.

I do find it a little strange that the low price is offered even on a sample order. If this is a sign if things to come, other companies in china will have to follow and drop their prices as well. Lets not get ahead of ourselves though. Have to see if this is for real, but damn, if it is.......


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## Technologic (Jul 20, 2008)

david85 said:


> I do find it a little strange that the low price is offered even on a sample order. If this is a sign if things to come, other companies in china will have to follow and drop their prices as well. Lets not get ahead of ourselves though. Have to see if this is for real, but damn, if it is.......


I'm not sure what to think of the 1.25/AH price for samples other than it's either 1) a really common standard product for them or 2) something else is up.

If it does turn out to be real (about 95% sure this company is legitimately selling/producing prismatic lithium cells) it would represent a rather huge leap forward for car battery prices. Possibly it could be subsidies from their bail out, but I doubt they trickled down that far yet.
She indicated, after some proding, that I could see as low as 25 cents/wh with enough pieces.

I did receive a LiFePO quotation at 47 cents/wh from another company, not sure if it's just a sign of the horrible sales conditions right now or just a sign of cheapening prices across the board.


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## GKnightBC (Sep 10, 2008)

The last quote I got for LiFePO4 batteries was this one, in Decemeber:

48V 100Ah battery packs:----USD2427 / pack ( 1.61/Ahr at 3.2V)
48V 100Ah BMS -----USD62.00/ PCS
48V 10Ah charger -----USD70.00/ PCS

Talk about plummetting pricing!!

I am glad I haven't ordered mine yet.


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## booksix (Aug 26, 2008)

Any idea how many units would need to be in an order to get the .25/wh price?


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## Technologic (Jul 20, 2008)

booksix said:


> Any idea how many units would need to be in an order to get the .25/wh price?


Probably over 500... maybe 1000... pricing doesn't really change from 1000-10,000 she said so.... which makes sense on a larger bigger ticket item.
I tend to negotiate with the chinese rather than just accepting their first offer, in this case though, I think she was really trying to get my order.


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## Jason Lattimer (Dec 27, 2008)

Just curious but, 
How much range dif. would be from 100 amp hour lithiums verses 225 amp hour trojans. I know the weight is different, but how much extra range do you get from the lighter batteries?


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## Technologic (Jul 20, 2008)

Jason Lattimer said:


> Just curious but,
> How much range dif. would be from 100 amp hour lithiums verses 225 amp hour trojans. I know the weight is different, but how much extra range do you get from the lighter batteries?


Depends... the same KWhr in theory should give the same range... however, you can't drain LA past about 50% DOD... these can go to 0% before recharging. 

2ndly the higher C rating of these batteries cut down on losses there. In general lithium batteries have a lower internal resistance which helps as well on range.

I'd say given this battery vs. the trojan listed... you'd see about 1.2times the range with lithium on average all things taken into account... but the trojan is actually almost quadruple the listed power of the lithium battery... so...


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## TheSGC (Nov 15, 2007)

Jason Lattimer said:


> Just curious but,
> How much range dif. would be from 100 amp hour lithiums verses 225 amp hour trojans. I know the weight is different, but how much extra range do you get from the lighter batteries?


From what I can tell a 100 Ah LiFePO4 battery is the same as a 225 Ah trojan in range, and you should see better acceleration with the lithium due to the lighter weight. If you had a 100 Ah lead battery pack and replaced it with a 100 Ah lithium pack, you should get twice the range because of the weight and Puekert's effect.


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## Technologic (Jul 20, 2008)

TheSGC said:


> From what I can tell a 100 Ah LiFePO4 battery is the same as a 225 Ah trojan in range, and you should see better acceleration with the lithium due to the lighter weight. If you had a 100 Ah lead battery pack and replaced it with a 100 Ah lithium pack, you should get twice the range because of the weight and Puekert's effect.


More like 3-4 times... because LA can't be safely taken below 50% DOD without ruining it's life cycle.

Effectively a 9kwh pack of this is the same as 19-20kwh of trojan batteries... before counting the weight... the low weight not only increases acceleration it increases range as well as the car will draw less to accelerate.


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## Jason Lattimer (Dec 27, 2008)

That is wonderful to know. I will be building a three wheeler and did not know about the 50% DOD on LA. That and the fact that I wont have to water the lithiums or change out the pack for a long while.

I will be looking forward to hearing more info on where these become available and how well people are doing with them.


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## david85 (Nov 12, 2007)

While it is true that you can discharge the cells all the way to so called 0%, you are not actually completely dishcarging the cells. There is a upper voltage limit and a low voltage cut off to stay inside of. Ideally you would want to only go to about 70% DOD to get the best performance out of a LiFePO4 battery. But for the odd time, you could get away with dropping the cell voltage all the way down to 2.5-2.2V which is considered the 0% mark (just don't go any further). My testing showed that amps start to fall off a cliff after 2.5V in the discharge cycle, so going any further past 2.5V is pointless anyway.

It is also possible to discharge lead acid deep cycle batteries past 50%, but the 1/2 way mark is the best overal compromise for range, battery life, and long term battery replacement cost for calculating net cost of ownership of the vehicle.


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## Frank (Dec 6, 2008)

Actually there are BMS available that do most of the critical functions: look on the endless-sphere and battery vehicle society forums for DIY and some commercial systems. http://liionbms.com/php/bms_options.php is a list of some that are available. Prices are pretty variable however....


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## rmay635703 (Oct 23, 2008)

Frank said:


> Actually there are BMS available that do most of the critical functions: look on the endless-sphere and battery vehicle society forums for DIY and some commercial systems. http://liionbms.com/php/bms_options.php is a list of some that are available. Prices are pretty variable however....


I notice in that list is a company in India, a little OT in this thread but there have been rumors of the $10k (converted for our pleasure) lithium powered city buses in India on a few forums several years back. I encountered a business women from India at the local energy fair marketing biosmass systems and asked her if she had heard anything about the Indian gov. making very low cost lithium powered vehicles for key cities and her answer was yes but that she didn't know anything about what companies were making the batteries. She was under the impression they were produced in India though.

This brings up a question, does anyone here have the power to overcome the language barrier that seems to exist between us and India? Many fairly sizable companies in India have no internet presence we can search so we must resort to older means. 

Anyone ever hear anything about India producing lithium batteries? Anyone have contacts in India that can provide any info? The companies that would be doing so could take advantage of Indias low cost reserves of lithium (much greater than most parts of the world) and obviously low labor costs. I don't think they are in a mass production stage as of now but they may become players if we can figure out who they are? I did hear of one foreign company trying to setup a plant there in coorporation with an existing Indian company, but was under the impression there were already startups making lithium batteries in India for several years now.

Cheers
Ryan


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## david85 (Nov 12, 2007)

Ryan, I don't think there will be much of a language barrier in india. The international language of trade is english. Indeed english still has a lot of hold left in india from the british empire. Just as in the case of dealing with chinese merchants, I would expect they would have some one on staff that can handle english inquiries.


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## DIYguy (Sep 18, 2008)

I know a PEng Mech from India very well. He worked for me for many years. I could ask him what he knows. Being technical, he may know or be able to find out. I think David is right though, English is prominent there in the business world I believe. (I have no direct experience though). I could ask if you like.

Gary


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## Technologic (Jul 20, 2008)

Frank said:


> Actually there are BMS available that do most of the critical functions: look on the endless-sphere and battery vehicle society forums for DIY and some commercial systems. http://liionbms.com/php/bms_options.php is a list of some that are available. Prices are pretty variable however....


the only option on that list that is a real BMS wants a 2500 dollar "handling fee".... blech.


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## GTWCMT (Jan 22, 2009)

Just some usless comment.... might put some light on it for you..
In November 2008 there was a meeting in china/japan about the development of lower cost lithium based batteries and that the prices had to drop so that they could address issues, there was simalar talks here in the UK about the battery pack costs and that they would need to become lower for Eco cars to become viable. This was a statment released by the department of tranport, it also noted the meeting that was held in china/japan.

It would seem that the tide has changed, the minister (government not religious) had had a trip in a EV and the new tesla and was activly promoting EV's. it went on to talk about start up businesses and making funds available, a £20,000,000 fund has been set up for EV's and their developement.
So it could be that many of the governments around the world are taking note and bring down the costs, I believe that the USA is not part fo the group that deals with these matters, so you would probaly find domestically the prices will not change.

Maybe with your new president, you could try dropping him a note to see what hes going to do about it, one of the factors that may help, is that Austrialia seems to be at the forefront in energy generation as I have noticed quite a lot of new things coming from there in the past two years or so.

I will post a thread up in this section with some info as it is related, and I will see if I can find the links to the videos so you can take a look as its a good thing.


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## JRP3 (Mar 7, 2008)

Any new info on this battery?


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## Technologic (Jul 20, 2008)

JRP3 said:


> Any new info on this battery?


Waiting for it to arrive... Chinese New year is going on till next week.

I'll keep everyone updated.


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## RKM (Jun 9, 2008)

Technologic,

I recieved a quote of .50/Wh on TS cells this week. Their LFP price is remaining firm.

Consequently, I'm pinning my hopes on your supplier being reputable and having a product as good as or better than TS (hoping for too much!?). I'd like to have cells in hand in May or June. I so want this .35/Wh price to be real!

Thanks again for purchasing a sample, testing and sharing your results. Lots of us are really hoping it works out this time.

Rob


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## Technologic (Jul 20, 2008)

RKM said:


> Technologic,
> 
> I recieved a quote of .50/Wh on TS cells this week. Their LFP price is remaining firm.
> 
> Consequently, I'm pinning my hopes on your supplier being reputable and having a product as good as or better than TS (hoping for too much!?). I'd like to have cells in hand in May or June. I so want this .35/Wh price to be real!


We will see, it appears to be quite similar to TS, but I can not know for sure until the battery actually arrives and I can manually test it.

Cheers.


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## icebeater (Jan 21, 2009)

*What about the 3C max. discharge rate???*

Have you considered that these batteries are only rated at 1C continuous (<100A) and 3C pulse (<300A?) I don't think you're going to get a lot of power out of them at high RPM. TS EV batteries are rated at 3C continuous and 10C pulse - you'd have to buy 3X the AH of these cells for the same peak performance as the TS batteries. 3 X .35 = 1.05 = still cheaper than TS but if you're running a lithium only battery pack and want peak power, you'll probably need the 200AH cells at least. I think these may be what the manufacturers sell as "high energy" batteries as apposed to the high power batteries like the TS. Interesting to see how big the price break can be for battery discharge performance. It was actually these high energy batteries that first got me thinking about using a battery pack of BatCap 2000's in parallel to the lithium pack for pulse power - now I'm back to that idea (discussed this on a recent thread here about supercaps - I'll try find it.) 

P.S. I also can't wait till your battery arrives.


----------



## Technologic (Jul 20, 2008)

*Re: What about the 3C max. discharge rate???*



icebeater said:


> Have you considered that these batteries are only rated at 1C continuous (<100A) and 3C pulse (<300A?) I don't think you're going to get a lot of power out of them at high RPM. TS EV batteries are rated at 3C continuous and 10C pulse - you'd have to buy 3X the AH of these cells for the same peak performance as the TS batteries. 3 X .35 = 1.05 = still cheaper than TS but if you're running a lithium only battery pack and want peak power, you'll probably need the 200AH cells at least. I think these may be what the manufacturers sell as "high energy" batteries as apposed to the high power batteries like the TS. Interesting to see how big the price break can be for battery discharge performance. It was actually these high energy batteries that first got me thinking about using a battery pack of BatCap 2000's in parallel to the lithium pack for pulse power - now I'm back to that idea (discussed this on a recent thread here about supercaps - I'll try find it.)
> 
> P.S. I also can't wait till your battery arrives.


These batteries are rated 3CA continuous and 10CA impulse for discharging. You can find the link on the first page to the specs.


----------



## icebeater (Jan 21, 2009)

*Re: What about the 3C max. discharge rate???*



Technologic said:


> These batteries are rated 3CA continuous and 10CA impulse for discharging.


Woohoo - never been so happy to be wrong! Now let that battery arrive already! I'm sure I'm not the only one watching this thread with check book in hand - I wonder if we could get 25c or 30c for a bulk order.


----------



## Technologic (Jul 20, 2008)

*Re: What about the 3C max. discharge rate???*



icebeater said:


> Woohoo - never been so happy to be wrong! Now let that battery arrive already!


New years is still going on there till this week 

I'll let everyone know once it arrives.


----------



## Hondacrzy (Mar 15, 2008)

Now I am going to add my .02.
I work for Honda and the Civic Hybrid Bms monitors its batteries in 14.5 volt segments. There is 10 input voltages for the 144 volt pack. I know were not talking about the same kind of batteries but I agree it would be a very complex system to monitor every battery. If this works out I think I will be building a new Conversion!!!

Cheers 
Chris


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## Technologic (Jul 20, 2008)

The sample should be arriving sometime early next week.

I have a little 4v x 2amp charger I will be attempting to use ... We'll see if I need to make my own blech


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## ToyBuilder (Dec 23, 2008)

Hondacrzy said:


> Now I am going to add my .02.
> I work for Honda and the Civic Hybrid Bms monitors its batteries in 14.5 volt segments. There is 10 input voltages for the 144 volt pack. I know were not talking about the same kind of batteries but I agree it would be a very complex system to monitor every battery. If this works out I think I will be building a new Conversion!!!
> 
> Cheers
> Chris


I recall a BugE that has a BMS built by the owner. He called it a Lithium BugE. He built his own BMS. His system monitors 24 TS 3.2 batteries individually down to the 2.5v level. For more info, look up www.nappepin.com/LithiumEV.htm. He talks about his board and shows pics of it online.


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## JRP3 (Mar 7, 2008)

He's charging to 4.2 volts, which as I understand it is really too high for long life and should be kept at 3.6 - 3.8 max.


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## Technologic (Jul 20, 2008)

JRP3 said:


> He's charging to 4.2 volts, which as I understand it is really too high for long life and should be kept at 3.6 - 3.8 max.


3.9v will work for these... 4v which I will be using is too high, but I don't intend to keep the sample outside of testing abuses so. 
Ideally 3.8-3.9v for these batteries I've come across is going to be best.


----------



## LiFePo4 packs (Feb 4, 2009)

hello,

We make battery specialised in LiFePo4 Li-ion batteries and packs for E-bike and EV.
OEM, ODM acceptable
Samples available

http://www.kayobattery.com

Pls don't hesitate to contact me if you are interested

Arthur Lee

[email protected]


----------



## JRP3 (Mar 7, 2008)

LiFePo4 packs said:


> hello,
> 
> We make battery specialised in LiFePo4 Li-ion batteries and packs for E-bike and EV.
> OEM, ODM acceptable
> ...


Too small for EV's unless you want to parallel a bunch together.


----------



## TheSGC (Nov 15, 2007)

So has the sample arrived? I am itching to see some pictures and testing data. I am just breaking in my lead acid pack, but my next pack will be LiFePO4 if this $0.35/Wh works out. I too have a 96 volt system, and I would get the same system you plan on getting , 96 volts 90 Ah pack.


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## Technologic (Jul 20, 2008)

TheSGC said:


> So has the sample arrived? I am itching to see some pictures and testing data. I am just breaking in my lead acid pack, but my next pack will be LiFePO4 if this $0.35/Wh works out. I too have a 96 volt system, and I would get the same system you plan on getting , 96 volts 90 Ah pack.


You can be sure I will update the thread the day it arrives  I know it was sent, but I have no data after that. Namely because of the New Years being 10 days long there's no telling when it'll get here. I expect it before the end of the week.

I'm trying to decide how dynamic to make the testing, since life cycle is the main concern for cost/benefit analysis, I've contemplated fulling charging and testing this battery with many partial discharges/charge cycles (say 50) and see if there's any measurable effect in DOD (there shouldn't be but maybe 0.01-0.02v. I could map and charge the nominal voltage after each small test and it'd only take a week or two to test this(during my free time).

I don't have the large charging capacity to see if I can damage the sample and see how "sturdy" it is, but I intend to test the large 3C-10C discharge ratings though


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## david85 (Nov 12, 2007)

Actually, I hate to break this to you, but in some cases, capacity will actually rise after the first 100 cycles. According to my info, the LiFePO4 cells require a good 7-10 cycles to settle in for the long haul.

Projected graphs suggest that lithium may actually continue that settling in process for several dozen cycles before leveling off and eventually starting to loose capacity.

All of this assumes that the info is accurate and honest though. So far I have not seen any reason not to believe it.


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## Technologic (Jul 20, 2008)

david85 said:


> Actually, I hate to break this to you, but in some cases, capacity will actually rise after the first 100 cycles. According to my info, the LiFePO4 cells require a good 7-10 cycles to settle in for the long haul.
> 
> Projected graphs suggest that lithium may actually continue that settling in process for several dozen cycles before leveling off and eventually starting to loose capacity.
> 
> All of this assumes that the info is accurate and honest though. So far I have not seen any reason not to believe it.


Well it's more just a graph that may or may not be useful for DIYers... I mean a plot showing every measured voltage through 50 cycles or more could prove illuminating? Maybe it's not worth my time, but I enjoy being thorough, and it will at least give me a hint as to build quality I hope.

If I see wild shifts during stable/monitored charging discharging cycles, something could be potentially wrong? 

At any rate, this will be my money, as well as anyone else that wants to trust my experience, so I want to give as much information as possible as quickly as I can get it, if I had a more lab style setting I could power charge this and do more cycles, but I can't find a proper high amperage PSU for 4v... so I'd have to build one.


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## Efiero (Feb 7, 2009)

wow still need to be cheaper that works out to be for the car i am thinking of at $5000 to go 60 miles at 75 MPH if i did all the math correct


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## Technologic (Jul 20, 2008)

Efiero said:


> wow still need to be cheaper that works out to be for the car i am thinking of at $5000 to go 60 miles at 75 MPH if i did all the math correct


You did the math very wrong  

My 96vx90AH pack in my custom car build will go anywhere from 300miles-500 miles per charge (I can't actually know for sure outside of theory at this point).

Also that pack would need replaced after 200-300k miles... no interm maintenance


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## david85 (Nov 12, 2007)

Technologic said:


> Well it's more just a graph that may or may not be useful for DIYers... I mean a plot showing every measured voltage through 50 cycles or more could prove illuminating? Maybe it's not worth my time, but I enjoy being thorough, and it will at least give me a hint as to build quality I hope.
> 
> If I see wild shifts during stable/monitored charging discharging cycles, something could be potentially wrong?


It would be a good way to help manage risk associated with buying offshore batteries. I would certainly be more confident if your info backs up the factory claims...Even it if is only a 10% snapshot of the minimum claimed lifespan.

Your testing will be a helluva lof more thorough than mine was, thats for sure.


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## JRP3 (Mar 7, 2008)

Technologic said:


> You did the math very wrong
> 
> My 96vx90AH pack in my custom car build will go anywhere from 300miles-500 miles per charge (I can't actually know for sure outside of theory at this point).
> 
> Also that pack would need replaced after 200-300k miles... no interm maintenance


Tech, buddy, I really wish you'd stop comparing your theoretical super light aero custom vehicle performance to the rest of the world, you might give people who don't know any better unrealistic expectations. I calculated a similar result to efiero's, and though he may not think so a 60 mile lithium pack for $5K is very reasonable, even ground breaking.


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## Efiero (Feb 7, 2009)

I am sure that will go much further in a super light car but in a 3000 lbs car with a full bodie it will take the fiero about 248 watt hours a mile i migh have come up with this the wrong way tell me if its wrong 25 HP to go 75 Mph so 25 X 746 = 18650 watt hours then devide 18650 by 75 thats how many miles you will travel in one hour at speed it =248.6666 watt hours a mile then just devide your total watt hours by 248.666 correct and from my math if it took you only 5 HP to go 75MPH you only get like 173 miles that is 96 volts and 90 amp hours you will need a realy slipery car to only use 5 HP at 75mph now at a slower speed yes i think the numbers work


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## Technologic (Jul 20, 2008)

Efiero said:


> I am sure that will go much further in a super light car but in a 3000 lbs car with a full bodie it will take the fiero about 248 watt hours a mile i migh have come up with this the wrong way tell me if its wrong 25 HP to go 75 Mph so 25 X 746 = 18650 watt hours then devide 18650 by 75 thats how many miles you will travel in one hour at speed it =248.6666 watt hours a mile then just devide your total watt hours by 248.666 correct


A lithium pack like that wouldn't weigh a car 3000lbs... and you're also wrong about the HP figures needed to go a certain speed in general.

HP figures to sustain a speed (75mph which is over the limit by 10 mph in most states' highways), you'd need to figure out the Cd (coefficient of drag) + weight to find out additional drag (in lbs), etc.

Then calculate mass x velocity = momentum.

You also failed to calculate in efficiency problems in your design.

My personal design at 65mph should have something like 800lbs of effective weight for the car (assuming I don't attempt to aerofoil some of this off... I know, unstable). + rolling resistence (about 15lbs)... so we're left with a sum of 54lbs of drag to overcome...

http://www.diyelectriccar.com/forum...rticle-drag-coefficients-and-their-27113.html

If you take his formulas (he doesn't explain them) that leaves my build somewhere about 8.6 HP to overcome to go 65. 

I don't think his numbers are completely accurate, but it's not deeply important atm. weight has a direct bearing to many resistances to sustaining speed.


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## Technologic (Jul 20, 2008)

JRP3 said:


> Tech, buddy, I really wish you'd stop comparing your theoretical super light aero custom vehicle performance to the rest of the world, you might give people who don't know any better unrealistic expectations. I calculated a similar result to efiero's, and though he may not think so a 60 mile lithium pack for $5K is very reasonable, even ground breaking.


Sure it's reasonable (considering it's useable cycle life), however I was merely making the point without context the statement meant nothing (though in my own way I suppose )

60 mile range could be a standard "Voltish" like 2000lb or so conversion... you stuck a 10-12kwh pack ($3200-4400) in a del sol or many common cars used on this forum you'd be seeing a curb weight of about 2200 lbs all said and done, which should yield 60 or so miles per charge on highways (or upwards of 80 if you're going in the 40s).

Much of my build is theory still, which I apologize for, since I'd much prefer building to schooling at this point 

I still encourage people to cut weight from dead body panels if they're going lithium... just saves you money and effort, and DOD of the batteries mileage wise.

I realize most can't do that or don't know what could be cut, but in general I think if you're looking for something like 100miles of range at 70mph, you need to be thinking custom, and need to be contemplating better materials outside of steel for the construction, not worrying so much about batteries.

I could see a 1000 lb lithium car existing with all creature comforts of any BMW, just made out of different things other than steel.

But Cd, and Area are still the most important for the speeds and range EF wanted. Area being ignored too much from the above guy's calculations (from my link)



david85 said:


> It would be a good way to help manage risk associated with buying offshore batteries. I would certainly be more confident if your info backs up the factory claims...Even it if is only a 10% snapshot of the minimum claimed lifespan.


500 cycles certainly would be disappointing in such a stable setting (if the slope of the graph showed that after 50 cycles). You could, in theory, predict the entire ideal cycle life off of a function (if one is even possible for DOD). At any rate, I have lots of time to spend till summer when I will actually begin my build full swing, so I figured I would really abuse what raw data I can get to make my choices. 

In my application I will rarely be discharging the batteries more than 70-80% DOD, which is the main area I want tested (namely if cycle life warrants me waiting days to recharge, or recharging at every opportunity). My gut tells me to recharge only at 20% or 10% DOD to get max mileage out of a battery pack, which is why I want to do trickle tests etc. for many cycles to see if any notable drop occurs (if I'm losing a few hundredths of a volt by the end, then I'd know cycle life is being damaged close to the same)


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## Efiero (Feb 7, 2009)

well you need to know your areo drag that and frontal area and how much power it take to push that frontal area through the air a fiero at 75mph takes 25 HP like it or not and i doubt even at 65 MPH you can build a car with a frontal area that will take 5 HP or less frontal area is the most important thing well maybe i am wrong but its gona be a one seat areo. Areodynamics are the most important thing not wight and mass that work in acceration but going through the air i mean if it where true what you are saying then a fiero could do about 160 mph with 80 HP but it takes more like 200 WHP


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## JRP3 (Mar 7, 2008)

I think people should calculate for real world worst case scenario then try to improve from there. Most conversions come in around 3000 lbs and are stuck with the aerodynamics they came with, though some tweaking can help. 250-300 wh/mi seems to be average, some can be better, some much worse, but a useful number for general calculations. Since efiero and I are both converting Fieros that weigh around 2500-2700 stock, once we remove the motor and add the lithium we'll end up around stock weight, depending on how much battery we use. I'm aiming for 96 or 108 volts of 100ah so I'll have 9.6 or 10.8 KW, at 250 wh/mi I'll get 38 or 43 miles and at 300 I'll get 32 or 36 miles. 30 miles will be enough for me so anything else is a bonus. A belly pan, rear wheel covers, and LRR tires would probably help out some but I don't do a lot of highway driving so they may not be worth it for me. I'll probably do the belly pan anyway to keep dirt and water off components.


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## GKnightBC (Sep 10, 2008)

I am not sure if I got this right, but 96v at 90Ahr is 8100Whr, right? At the typical 250 Whr per mile, that doesn't get someone more than about 32 miles. How can you get 300-500miles? that's only 25 Whr per mile, which is less than a motorcycle?!?


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## Technologic (Jul 20, 2008)

GKnightBC said:


> I am not sure if I got this right, but 96v at 90Ahr is 8100Whr, right? At the typical 250 Whr per mile, that doesn't get someone more than about 32 miles. How can you get 300-500miles? that's only 25 Whr per mile, which is less than a motorcycle?!?


www.aptera.com for an example 

Car uses 10,000whr and gets 100-120miles of range with a DC motor.

250whr = a heavy car, crappy drag coefficient, and large frontal area... things my build will all lack.

The aptera effectively gets about 80whr-mile or so... I expect about 3 times less than that or more considering weight reduction will be about 1/3rd the aptera's curb weight and area about 70% what the aptera is.

Drag coefficient on a motorcycle is actually very poor.

I'm not 100% sure I'm going 30 or 35 batteries yet as well, I might actually do 10kwhr, but I don't really think I need over 200 miles anyway let alone closer to 500 maybe?

Moving less weight takes less power, moving less drag takes less power, and driving something with less area takes less power... it's a fairly linear relationship as well...

My (hopeful) design's cross sectional area for instance is almost 11 times smaller than a H2's...

Worst case I can't see my pack plans getting less than 150 miles of range... but they'll probably surprise me on the high side.


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## JRP3 (Mar 7, 2008)

Technologic said:


> http://www.aptera.com
> 
> 250whr = a heavy car, crappy drag coefficient, and large frontal area...


I've seen converted Geo Metro's getting worse than 250 whr, and they aren't heavy, don't have a large frontal area, and probably don't have a terrible drag coefficient. 250 watt hours per mile is not bad at all, most conversions are getting worse than that.


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## Technologic (Jul 20, 2008)

JRP3 said:


> I've seen converted Geo Metro's getting worse than 250 whr, and they aren't heavy, don't have a large frontal area, and probably don't have a terrible drag coefficient. 250 watt hours per mile is not bad at all, most conversions are getting worse than that.


Isn't a metro's Cd like 0.39? 

It's all about scale I guess... anything over 1500 lbs is heavy to me.

Also are you including LA effects from puetkert effect etc?

I'd say a geo metro's like 8-10ft2 frontal cross section to be larger. Maybe not abnormally large by today's standards though.


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## JRP3 (Mar 7, 2008)

Technologic said:


> Isn't a metro's Cd like 0.39?


.32 for the Gen 3


> It's all about scale I guess... anything over 1500 lbs is heavy to me.


 You live in a different dimension where the laws of physics are altered  Vehicles should weigh nothing, run forever on 2 D batteries, have the Cd of a toothpick, and everyone should build theirs from scratch  Nice place, I'll have to visit sometime


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## Technologic (Jul 20, 2008)

JRP3 said:


> .32 for the Gen 3
> You live in a different dimension where the laws of physics are altered  Vehicles should weigh nothing, run forever on 2 D batteries, have the Cd of a toothpick, and everyone should build theirs from scratch  Nice place, I'll have to visit sometime


lol it's easier to alter one's own circumstances than wait for others to create altered ones 

There's clearly a start limit here...namely the weight of human beings :S

You could press a 1 piece car out of diamond, make it weigh 30 lbs and be stronger than a 3000lb steel car... and you're still stuck with the waist size of the average american


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## GKnightBC (Sep 10, 2008)

Technologic said:


> www.aptera.com for an example
> 
> Car uses 10,000whr and gets 100-120miles of range with a DC motor.
> 
> ...


I checked out Aptera's Website, and so far, they have no info on thier car except the charge time, which calcs out to 13kwhr (110v * 15a * 8 hrs) 'estimated' charge time. And, considering that there are next to no details on the car itself, I would like to know where you got your information? The first car was just driven off the manufacturer's lot on Feb 6th, and they say they have no idea as to its range, etc.


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## Technologic (Jul 20, 2008)

GKnightBC said:


> I checked out Aptera's Website, and so far, they have no info on thier car except the charge time, which calcs out to 13kwhr (110v * 15a * 8 hrs) 'estimated' charge time. And, considering that there are next to no details on the car itself, I would like to know where you got your information? The first car was just driven off the manufacturer's lot on Feb 6th, and they say they have no idea as to its range, etc.


 
Well they used to have lots of information up (their website has changed).

On the wikipedia link it talks about their curb specs.

1900lb curb weight.

the car's 120 mile range makes it the lowest watt-hour/mile car ever mass produced
http://en.wikipedia.org/wiki/Aptera_Motors

They sorda embarassed the EV1 IMO 

Several of the website's data has been confused with the addtions of the 2e... which claims a 891lb curb weight and 19kw engine (possibly they cut down 1000 lbs of weight?) If so they may be attempting to either cut costs, or boost the range substaintally...

It doesn't say much, data is sparse besides the data about the Mk-0


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## Efiero (Feb 7, 2009)

JRP3 i dont think it could be said any better you have to be real i admit i get out on a limb but not like that


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## GKnightBC (Sep 10, 2008)

I swear I must be on a different internet than you, techno! 
From the wiki page:
Curb weight1,500 lb (680 kg)Fuel capacity10-13 KWh Lithium-ion batteryElectric range*2e:* 100 mi (160 km)



You mentioned a curb weight of 1800lbs and a range of 120miles. While they have an estimated delivery of 2010 for consumers, I think I'll still get mine working first.


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## Technologic (Jul 20, 2008)

GKnightBC said:


> I swear I must be on a different internet than you, techno!
> From the wiki page:
> Curb weight1,500 lb (680 kg)Fuel capacity10-13 KWh Lithium-ion batteryElectric range*2e:* 100 mi (160 km)
> 
> ...


As I said the data has changed significantly since I last checked the wiki.

They list two different specs for the MK-2e.
Aerodynamic optimization using simulations and light-weight composite construction yields a vehicle which consumes only 80 Wh/mi at 55 mph (89 km/h), about half the energy needed to propel the EV1. On the battery electric model, this means a *120-mile (190 km) range on 10 kWh* of electricity, or around 340 mpg price equivalent

This is where I've always heard about the 10KWh pack and 120 mile range.

I'm not holding my breath for aptera, their numbers just seem like a decent baseline.

They have also seemingly changed the weight with every new version they release.  Possibly to accomodate the ridiculous amount of cameras and electricity the car uses while driving. There's 3 always on cameras/LCDs and always on GPS/stereo, etc with it's own LCD in the car, always on climate control (via seats).

The car's MPG was tested though for the MK-0 by some other company, and they got like 330mpg out of a diesel engine.


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## GKnightBC (Sep 10, 2008)

Re: the changes in weight

Aha! So this would be the case of the amazing disappearing car! 
I browsed through the other competetors for the X-Prize, and almost all of them are in worse shape than Aptera. Most of them don't even have a concept car or drawings. A damn shame.


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## speculawyer (Feb 10, 2009)

Technologic said:


> www.aptera.com for an example
> 
> Car uses 10,000whr and gets 100-120miles of range with a DC motor.
> 
> ...


I agree that you are being unrealistic. The Aptera has done a pretty good job. It has a Cd of 0.15 and a curb weight of 1500lbs. I really can't see you getting 3X the performance of that highly optimized vehicle unless you are designing a missile that you crawl inside with a few wheels on it.

To learn more about the Aptera, I highly recommend www.apteraforum.com

This $0.35/wh number is what I'm interested in. I've been skeptical on Aptera being able to meet their price target but if they can get batteries for $0.35/wh, I think they might be able to do it. They use a 10Kwh pack (although recent specs say 10 - 13 Kwh) and get 100 miles at a constant 55mph. 

Hell, at $0.35/wh, the EV market will finally take off for real. The USA could actually become energy indepedent if everyone drove EVs. (The oil we produce could be used for long-haul requirements such as trucking.)


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## speculawyer (Feb 10, 2009)

Technologic said:


> <some out-dated Aptera info>


The specs are not set in stone yet, but Aptera did recently demo their vehicle at the TED conference. Here is a great article filled with Aptera specs written by woman that has been very closely tracking the progress of the Aptera.


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## Technologic (Jul 20, 2008)

speculawyer said:


> The specs are not set in stone yet, but Aptera did recently demo their vehicle at the TED conference. Here is a great article filled with Aptera specs written by woman that has been very closely tracking the progress of the Aptera.


hmph the only spec is a Cd of 0.15


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## speculawyer (Feb 10, 2009)

Technologic said:


> hmph the only spec is a Cd of 0.15


It is a 3 page article . . . I think you only looked at the 1st page. The 3rd page has some more specs . . . but not a lot of detail. Here's the ones you are probably most interested in:


> *Official Specifications:*
> Dimensions: 53″ high x 91.0″ wide x 173″ long.
> 111″ wheelbase
> 80.5″ front track.
> ...


They've indicated that they are going to make the final version about 6" narrower since it is pretty hard to get into a garage as is.


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## NeilBlanchard (Feb 11, 2009)

Technologic said:


> www.aptera.com for an example
> 
> Car uses 10,000whr and gets 100-120miles of range with a DC motor.
> 
> 250whr = a heavy car, crappy drag coefficient, and large frontal area...


It has an AC motor AFAIK. The stated curb weight is 1500 pounds. It has a drag coefficient of 0.15, and based on the frontal area measurements I did, it has a CdA of 0.27.


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## Technologic (Jul 20, 2008)

NeilBlanchard said:


> It has an AC motor AFAIK. The stated curb weight is 1500 pounds. It has a drag coefficient of 0.15, and based on the frontal area measurements I did, it has a CdA of 0.27.


It does not use an AC motor or regen braking...

if it did it's range would be 10-20% higher (around 140 miles). It specifically says it uses a small 18HP DC motor many times, all versions have used that motor.

Well the Cd of 0.15 is definitely the first time it's been printed. They first released an estimate of 0.05 then 0.11 once the Mk-0 was made... but I heard they added side mirrors and a fin on the back in the Mk-2 which probably hurt the Cd quite badly .

0.15 isn't even that awesome... and the front wheels are probably at least 0.05 of that Cd... if not more... (the lame "staple them on" look to it)

The car certainly can be improved upon, but it's still the best car made currently.


----------



## speculawyer (Feb 10, 2009)

Technologic said:


> *It does not use an AC motor or regen braking*...
> 
> if it did it's range would be 10-20% higher (around 140 miles). It *specifically says it uses a small 18HP DC motor *many times, all versions have used that motor.


Where do you get that info? I don't think that is correct.

There have been things like that mentioned 3 years ago but a lot has change. They even changed from rear-wheel drive to front wheel drive.


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## NeilBlanchard (Feb 11, 2009)

Hi,

The Aptera 2e Cd of 0.15 has been known for months; and yes it is a disappointment to have it increase from 0.11 of the Typ-1 Mk-1. Another contributing factor adding to the drag is the front wheel drive shafts.

The lowest Cd of any vehicle that I am aware of other than the Typ-1 , is 0.13 for the 1937 Schlor Pillbug.


















The models of the Mercedes Bionic "Boxfish" car was 0.06, but when they added wheels, and made a working prototype, it increased to 0.19.










The 1939 Maybach Stromlinienkarosserie had a Cd of 0.16 with flat windshield glass, and 0.14 with curved glass.


























Of course, the EV-1 had a Cd of 0.19, and with a few tweaks, it went 183mph; setting the speed record for a production car that year.

Having three wheels helps make certain things easier/better, and makes other thing neccessary -- like having a wide track. Aptera is working on a four wheeled (and four seat) car named Palomar, which will be built at a later date after the 2e is in production.

Remember that the Aptera is working with a 10kWh (or maybe 13?) battery pack. The Volt is projected to have a 16kWh pack and go just 40 miles all-electric. And the Tesla has a 53kWh pack to go 220 miles. So, 12 miles/kWh vs 2.5 vs 4.1 -- not too shabby.

I'm fairly certain the Aptera 2e's motor is AC:
http://www.daughtersoftiresias.org/apterawiki/Drivetrain
http://www.daughtersoftiresias.org/docs/AC24LS_DMOC445 Product Sheet.pdf


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## Technologic (Jul 20, 2008)

speculawyer said:


> Where do you get that info? I don't think that is correct.
> 
> There have been things like that mentioned 3 years ago but a lot has change. They even changed from rear-wheel drive to front wheel drive.


The wikipedia reiterates DC motors countless times... I have no reason to doubt it's accuracy?

Unless this was modified very recently... and they actually LOST range from the two prototypes after adding AC? (sign of too much investors destroying the company?), I suspect it's still the same low HP DC motor.

The way you get the Cd into the low <0.1 range is simply tucking the wheels into the aerofoil shape... it's actually something that is NEVER done... outside of prototypes made specifically for gas/MPG record setting.

It's foolish and silly to keep widening out the wheels, and especially to make the aptera front wheel drive... It in fact is probably the stupidest thing they could have done to the car short of totally redesigning the body to some crappy prius like shape. 

Adds weight, adds motor losses, adds a differential, adds additional costs, adds complexity, and requires a larger none streamlined area.

Rear wheel driving a 3 wheeler is just common sense to me.

That mercedes box fish, if it had wheel covers going down to about 5 inches of clearance on both the front and rears... keeping the shape... it would drop half of it's Cd. So why do these morons keep doing it? beats me. The only answer I have is their engineers are EXTREMELY limited on what they're allowed to build, or they simply hire moronic engineers from crappy schools to lead up their R&D

The pillbug should be obvious why it has a higher Cd than you'd figure... the shape is far too tall at the front. And all you're proving to me is furthering my suspicions that engineers in the 30s and 40s knew more with crappy technology than 40 year old lead engineers for GM can manage....

My virtual wind tunnels in SW on my "shape" minus wheels is showing something that should rival 0.03 + whatever the 3 wheels sticking out 5 inches will cause


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## JRP3 (Mar 7, 2008)

Technologic said:


> It's foolish and silly to keep widening out the wheels, and especially to make the aptera front wheel drive... It in fact is probably the stupidest thing they could have done to the car short of totally redesigning the body to some crappy prius like shape.
> 
> Adds weight, adds motor losses, adds a differential, adds additional costs, adds complexity, and requires a larger none streamlined area.
> 
> Rear wheel driving a 3 wheeler is just common sense to me.


Try driving it in the snow with a single drive wheel. Frankly I'm not a fan of the Aptera at all, or 3 wheelers in general. There is no reason you can't make an efficient vehicle with 4 wheels and a more user friendly shape. The main reason it's 3 wheels is so they can avoid governmental regulations. 3 wheelers are and will always be niche vehicles that appeal to a very few.


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## Technologic (Jul 20, 2008)

JRP3 said:


> Try driving it in the snow with a single drive wheel. Frankly I'm not a fan of the Aptera at all, or 3 wheelers in general. There is no reason you can't make an efficient vehicle with 4 wheels and a more user friendly shape. The main reason it's 3 wheels is so they can avoid governmental regulations. 3 wheelers are and will always be niche vehicles that appeal to a very few.


Well as I've said, it's the government that is stopping EVs, more so than selfish "companies".

The amount of regulations for a 4 wheeled car is astronomical (and costs to get it approved). Likewise MOST 4 wheel sedans are 1 wheel drive.


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## JRP3 (Mar 7, 2008)

But that one wheel is not riding in the center slush track and has a second wheel to help keep it from sliding sideways. Also many vehicles have traction control that can stop wheel slip.


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## david85 (Nov 12, 2007)

Oh don't even get me started on traction control systems! Sorry, but I'll never own a vehicle with ABS, ESP or any other electronic safety acronym LOL. Only this winter I have literally seen and driven through it all. And I have hit black ice, pushed through slushy southern BC snow (when packed it forms low density ice) and gone 70 MPH on hard packed powder on the highway. My 2wd pickup has a limited slip rear differential and thats about it. The rest is up to the driver to figure out. Through it all I did not once regret not having traction control. 4wd on the other hand.......maybe someday I'll find a front end with 3.08 gears. *sigh*

I think the aptera is a good example of what a 3 wheeler could be and I'll even admit to even liking the looks, but personally, I would never have use for one. JRP3 is right about the 3rd wheel going down the slush pile in winter, *or in summer the, oil slick*. It just isn't practical for less than ideal conditions.

Don't get me wrong, there is a place for such a hyper efficient vehicle, but I need something that can move more than just me, and I need 4 wheels for the conditions I have to drive in or the stuff I have to move. Also considering the title of this thread, it may not be as critical to get a perfect teardrop shape when you consider the falling price of lithium batteries.


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## Technologic (Jul 20, 2008)

david85 said:


> Oh don't even get me started on traction control systems! Sorry, but I'll never own a vehicle with ABS, ESP or any other electronic safety acronym LOL. Only this winter I have literally seen and driven through it all. And I have hit black ice, pushed through slushy southern BC snow (when packed it forms low density ice) and gone 70 MPH on hard packed powder on the highway. My 2wd pickup has a limited slip rear differential and thats about it. The rest is up to the driver to figure out. Through it all I did not once regret not having traction control. 4wd on the other hand.......maybe someday I'll find a front end with 3.08 gears. *sigh*
> 
> I think the aptera is a good example of what a 3 wheeler could be and I'll even admit to even liking the looks, but personally, I would never have use for one. JRP3 is right about the 3rd wheel going down the slush pile in winter, *or in summer the, oil slick*. It just isn't practical for less than ideal conditions.
> 
> Don't get me wrong, there is a place for such a hyper efficient vehicle, but I need something that can move more than just me, and I need 4 wheels for the conditions I have to drive in or the stuff I have to move. Also considering the title of this thread, it may not be as critical to get a perfect teardrop shape when you consider the falling price of lithium batteries.


There's probably ways to get around regulations in small volumes of 4 wheel cars, I just can't suffer the weight though... most states do have a custom car title for new vins that only have to be inspected.

Here in NC... it never snows...I mean once every 2 years for 3-5 hours on the ground and that's it... I don't think lithium batteries or this type of "simple, yet snazy" design will work for anyone in Tennessee and above.

I've actually had issues in recent years with my Car's ABS locking up... I still will probably include an ABS system on the front two wheels of my build.

Some ABS systems are upwards of 100lbs... a complete waste of weight... so I will have to pick out proper ones...

At any rate, I never really had issues driving down here with or without ABS... my car with ABS skidded into a fish tail before when attempting to avoid a wreck, and I never was in an accident in my non-ABS car.


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## david85 (Nov 12, 2007)

I have 3 concerns with the way that ESP has been deployed by OEMs.

1, they are often used to supplement the stability of vehicles that are otherwise "unstable" by the nature of their design, like SUVs that are marketed as a daily city commuter.

2, its used as an excuse to not worry about how to drive in less than perfect conditions. There are times when I wonder if drivers are actually getting dumber.

3, they don't seem to be very reliable. My Dad has a truck that is supposed to have 4 wheel ABS and every time it turns on in an emergency, it nearly causes a disaster. Once nearly ending up in a ditch because the front wheel locked up in a turn, and another time it killed so much of the braking power that he nearly hit a deer. Works fine on hard dry pavement when in a strait line though.

I know in theory the system can work to supplement even the most well designed cars in the hands of a skilled drivers but so far I haven't seen a good example of one in real. I hope you will be able to do better.


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## Technologic (Jul 20, 2008)

david85 said:


> I know in theory the system can work to supplement even the most well designed cars in the hands of a skilled drivers but so far I haven't seen a good example of one in real. I hope you will be able to do better.


Who knows...

Ideally I would want electromagnetic brakes on each wheel or AC... could be pulsed flawlessly in ultra high frequencies, or return the battery power through a "type" of raw AC pulse.

But the problem still is leftover "battery power" to waste on electromagnetic brakes, and AC motors don't brake quickly enough for crash ratings in any car that weighs very much.

Ideally a low weight car will brake extremely effectively... 
I haven't really "done the math" on the difference between ABS systems and electromagnetic brakes on a car's total efficiency...

But standard brakes don't take any power out of the system... ABS would, but probably not as much as electromagnetic brakes...

There's just so much better ways to do it... that none of us 20 somethings will even see in production until we're dead, simply because of regulatory malpractice in this country.

I mean why in the world can't you just pass inspections for a new car design by a few short brake trials? give me a break 

Just think about if you placed a set of neodymium magnets (with proper spaces) on the interior of the wheel up over exposed coils that then "charged the coils with DC current as you breaked"... same concept how electromagnetic trams stop (though it's two electromagnets). The controller for such a thing could just be a straight contactor step up DC transformer (or step down w/e you want). So simple and effective (and ZERO pads to replace etc).

I need to stop thinking like this, just maddening. Nothing will change no matter how many ideas I figure out that contrarily work.

You could also make a fairly cheap regen system using the same permanent magnet/charging coil system described above.


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## Voltswagen (Nov 13, 2008)

Technologic
Did you get the physical deminsions on this 90ah battery?


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## JRP3 (Mar 7, 2008)

145×220×68（mm） Same as TS
3 kg
5.71 x 8.66 x 2.68 (inches)
6.61 lbs.


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## JRP3 (Mar 7, 2008)

Seems to me since the 100 ah version uses the same case so it has the same dimensions it would make more sense to get the 100 ah version.


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## Voltswagen (Nov 13, 2008)

Thanks JR
Getting out the measuring tape....sharpening my pencil


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## Voltswagen (Nov 13, 2008)

After measuring the trunk of my Del Sol, I could easily fit 60 of these in there in one layer.
If the price for 100ah is almost the same as 90ah, I could do 30 strings of 2 parallel each which would give me 96v at 200ah. That is very healthy!
Almost sounds too good to be true.
Crossing my fingers...waiting to hear from Technologic.


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## RKM (Jun 9, 2008)

Voltswagen said:


> After measuring the trunk of my Del Sol, I could easily fit 60 of these in there in one layer.
> If the price for 100ah is almost the same as 90ah, I could do 30 strings of 2 parallel each which would give me 96v at 200ah. That is very healthy!
> Almost sounds too good to be true.
> Crossing my fingers...waiting to hear from Technologic.


Fantastic trunk on that del sol! You must have a 30X36 inch cavity! This must be a bonus of front wheel drive. I can only fit 18 of the 160Ah in the trunk of the Miata. How will you be for weight distribution?

I'm waiting for the good news from Technologic too. Really hoping this will be a price break on quality product. I remain a bit skeptical though (sad but true).

Rob


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## Technologic (Jul 20, 2008)

JRP3 said:


> Seems to me since the 100 ah version uses the same case so it has the same dimensions it would make more sense to get the 100 ah version.


I chose the 90AH version simply because it was the one they make the "most" and I assumed it would be cheaper that way.

It's quite possible going to larger amperages would yield more $/AH


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## Voltswagen (Nov 13, 2008)

Actually 43" wide x 30" deep. Narrows to 36" wide toward the passenger cabin of the car. My rows won't be even but I can get all 60 of them in there.
They made these trunks larger to allow storage of the Targa Top. 
Weight is approx. 400 lbs....I may have to beef up the rear suspension.
I saw somewhere on the internet that Acura rear springs will fit and they are stronger. Will have to research that further. I don't want to use spacers if I can avoid it.
C'mon Technologic.....give us a good report!


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## Technologic (Jul 20, 2008)

Voltswagen said:


> C'mon Technologic.....give us a good report!


We'll know soon 

I decided to use West Mountain's battery analyzer for the testing seen here:
http://www.westmountainradio.com/CBA.htm

I should be able to quickly discharge and recharge it (at selectable amperages up to 48amps during charging cycles). Also provide charts for each discharge cycle if I want.

I picked one of those up used for $40.

Hopefully I can better track the data this way, as well as abuse the battery to it's "fast charging" limits.


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## aktill (Jun 18, 2008)

Those CBAs are handy. I got a preproduction sample about 4 yrs ago, and it's very well done. Never used it for larger packs though.


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## david85 (Nov 12, 2007)

Technologic said:


> It's quite possible going to larger amperages would yield more $/AH


 
I've got that one covered for you actually.

Shortly after I found out who the company was, I contacted a sales rep through their online chatroom and secured an informal price for a 144V/180Ah battery (saved the chat transcript to my hard drive). Came to came to a price similar to what you were quoted......(before charger and BMS)

Maybe they would charge a premium for something like 400Ah, who knows, but it seems that the $/wh pricing is steady up to 180 ah so far. I asked for 200ah, but they didn't have that.


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## Technologic (Jul 20, 2008)

david85 said:


> I've got that one covered for you actually.
> 
> Shortly after I found out who the company was, I contacted a sales rep through their online chatroom and secured an informal price for a 144V/180Ah battery (saved the chat transcript to my hard drive). Came to came to a price similar to what you were quoted......(before charger and BMS)
> 
> Maybe they would charge a premium for something like 400Ah, who knows, but it seems that the $/wh pricing is steady up to 180 ah so far. I asked for 200ah, but they didn't have that.


That's good


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## Bowser330 (Jun 15, 2008)

I like this car better than the aptera...although it would be nice if it had normal opening doors and was a little bigger... (i know i would lose drag efficiency with the size increase)

http://car-reviews.automobile.com/Volkswagen/concept/2003-volkswagen-1-liter-concept-car/637/


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## Technologic (Jul 20, 2008)

Bowser330 said:


> I like this car better than the aptera...although it would be nice if it had normal opening doors and was a little bigger... (i know i would lose drag efficiency with the size increase)
> 
> http://car-reviews.automobile.com/Volkswagen/concept/2003-volkswagen-1-liter-concept-car/637/


I'm not such a huge fan of that car for several reasons, but it does get decent gas mileage.


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## Technologic (Jul 20, 2008)

The sample still hasn't arrived as of today, though I suspect that's entirely the fault of the holiday there.

My contact just confirmed last thursday that their main factory in shenzhen just received the sample and sent it out... so I expect it sometime soon?

No telling I suppose... it might take 10 days to get here by air because of customs 

Most places weren't reopening until feb 4th or 5th of last week, so I suppose I just need to be patient haha


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## sunworksco (Sep 8, 2008)

NeilBlanchard said:


> Hi,
> 
> The Aptera 2e Cd of 0.15 has been known for months; and yes it is a disappointment to have it increase from 0.11 of the Typ-1 Mk-1. Another contributing factor adding to the drag is the front wheel drive shafts.
> 
> ...


Here are some images of the Aptera front-wheel-drive axle shafts.
Still very little mass in the wind.
Changing the drive-train to the front-end is better for the brake re-gen system and is weight balanced for a three wheeler.The Blackjack Zero is similarly balanced...............................


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## sunworksco (Sep 8, 2008)

sunworksco said:


> Here are some images of the Aptera front-wheel-drive axle shafts.
> Still very little mass in the wind.
> Changing the drive-train to the front-end is better for the brake re-gen system and is weight balanced for a three wheeler.The Blackjack Zero is similarly balanced...............................


Here is the article from Autoblogg :


Yep, just after posting a story that Aptera seems extremely unlikely to get its first production model shipped before the end of 2009 comes news that essentially seals this fate. Aptera is now saying that all production models will be front-wheel drive, a major change to say the least. Previously, Aptera's preproduction models used a belt-driven rear wheel, leaving the two hoops up front alone to steer the vehicle. No longer, as Aptera offers the following reasons for the switch:

1. Better weight distribution, which, in turn, maximizes stability
2. Improved traction during acceleration and in inclement weather wet conditions
3. More efficiency at higher speeds
4. Increased durability during the life of the vehicle
5. Improved noise insulation
6. Increased rear cargo space (without sacrificing front legroom)

We're not going to spend any time arguing with any of those 6 points, but we're also fully aware that this change will further postpone sales of the 2e well into the future. For what it's worth, an Aptera Forum member named Steve (any guesses as to who that may be?) claims that the decision to switch to FWD was made all the way back in January.


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## speculawyer (Feb 10, 2009)

sunworksco said:


> Yep, just after posting a story that Aptera seems extremely unlikely to get its first production model shipped before the end of 2009 comes news that essentially seals this fate.


That article says that they were going to miss their end of year *2008* date. Current schedule is to start shipping October 2009. 



> Aptera likely to miss end-of-year delivery dateby *Jeremy Korzeniewski* on *Dec 24th 2008 *at 12:01PM
> 
> Well, here it is the end of the year and Christmas is upon us once again. Wouldn't it be a great gift to get a brand-new electric car? For those individuals that have placed deposits with Aptera, which has been working towards a goal of making its first deliveries by the end of *2008*, things are not looking promising.


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## yamez4u (Feb 10, 2009)

Any news on the battery testing? Also anyone found pricing on these:http://www.valence.com/products/battery_modules/


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## Technologic (Jul 20, 2008)

yamez4u said:


> Any news on the battery testing? Also anyone found pricing on these:http://www.valence.com/products/battery_modules/


I was told by the delivery company, Wednesday of this week it will be here.

Cheers


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## david85 (Nov 12, 2007)

yamez4u said:


> Also anyone found pricing on these:http://www.valence.com/products/battery_modules/


Valence seems to make a good product but they (like many- more like all- american battery companies) refuse to even talk to privateers like us let alone sell us their product. Although in the case of valence, I think they also are already making about as much batteries as they possibly can just supplying their current OEM customers so I guess I shouldn't be too hard on them.


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## Technologic (Jul 20, 2008)

david85 said:


> Valence seems to make a good product but they (like many- more like all- american battery companies) refuse to even talk to privateers like us let alone sell us their product. Although in the case of valence, I think they also are already making about as much batteries as they possibly can just supplying their current OEM customers so I guess I shouldn't be too hard on them.


For whatever reason their lifepo's are only 33% lighter they say than lead acid (vs. the 70% or so from prismatics)

hmmmmm


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## JRP3 (Mar 7, 2008)

The few price quotes I've seen from Valence were extremely expensive. I don't remember the exact numbers, just that I was shocked at how high they were


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## speculawyer (Feb 10, 2009)

JRP3 said:


> The few price quotes I've seen from Valence were extremely expensive. I don't remember the exact numbers, just that I was shocked at how high they were


Does this mean that the US makers will just get killed by China in the end? Will Valence, Enerdel, A123, and any others all go down in view of cheap competition from China?


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## Technologic (Jul 20, 2008)

speculawyer said:


> Does this mean that the US makers will just get killed by China in the end? Will Valence, Enerdel, A123, and any others all go down in view of cheap competition from China?


Highly likely since the US governments regulations and wage benefits require so much money to subsidize.

I mean LIFEbatt who uses cells from "somewhere" is based in america and their AH prices on large group buys are $2.65/AH (more than twice this price).


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## JRP3 (Mar 7, 2008)

Well you have to compare battery performance. The truth is that A123 cells can put out way more current, higher C rate, than Thundersky and clones. So ultimately A123 may own the performance and OEM market, who can afford their tech through volume, and the Chinese may dominate the lower end, where the rest of us exist. Or the Chinese will help drive down prices across the board. Who knows how it will really play out.


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## JRP3 (Mar 7, 2008)

Technologic said:


> I mean LIFEbatt who uses cells from "somewhere" is based in america and their AH prices on large group buys are $2.65/AH (more than twice this price).


Doesn't LIFEbatt use Phostech cells?


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## Technologic (Jul 20, 2008)

JRP3 said:


> Doesn't LIFEbatt use Phostech cells?


I honestly have no idea where they get them from.

You can get cylindrical lifepo's for cheaper than this (about 0.25/WH) rated for 15C discharge... why on earth you'd ever want that though is beyond me.

I think I will be extremely hard pressed in my build plans to hit over 2C


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## david85 (Nov 12, 2007)

I'm almost positive that lifebatt gets its supply from a jobber in Taiwan. I saw some info to suggest that a while ago. Naturally I didn't bother to save it (just speculation)

As far as the battery race between the USA and asia, I've said it before and I'll say it again...... There is no race, its over and asia won, period.

Quality is not everything. Just look at PCs vs macs. Only when the mac computers came down in cost (probably with a similar drop in quality) were they finally able to compete with PCs. Being the best isn't always what matters when it comes to consumer technology.

Striking the right compromise between quality and cost is what really matters, but thats not something that anyone normally likes to talk about when competing against some one else. a123 and valence can talk about quality and reliability till they are blue in the face. In the end if they cannot compete with the "good enough" chinese substitute product, then they will be trampled to dust.


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## JRP3 (Mar 7, 2008)

It's too early to tell. Remember high C rate means fast recharge as well. If fast charge stations become mainstream fast charging becomes a real option with cells that can take it. TS cannot, but Altairnano and A123 can. Those cells also have a much higher potential lifespan, time will tell how much, but these features may make the higher price more economical in the long run. Not to mention that battery technology is constantly improving, and all it takes is one company to hit the tipping point with quality, performance, and price, and they will either dominate the market or force all others to lower prices. We're in the early stages of a battery revolution, I wouldn't try to predict the outcome at this point.


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## Technologic (Jul 20, 2008)

JRP3 said:


> It's too early to tell. Remember high C rate means fast recharge as well. If fast charge stations become mainstream fast charging becomes a real option with cells that can take it. TS cannot, but Altairnano and A123 can. Those cells also have a much higher potential lifespan, time will tell how much, but these features may make the higher price more economical in the long run.


Like I said... 220v I can recharge my pack plans in about 2 hours... I have absolutely no need for more than that... 220v x 25 amps = 5kw... even at 90% efficiency my 10kwh (max) pack will be charged in about 2 hrs 30 min. Also as I said... you can find cylindrical cells for even less than this quotation... a lot less.

I doubt I will bother with 220 either, considering I hope to only recharge once every 2-3 weeks (even if I can only manage a paltry 200 mile range), 110v should work perfectly in about 6-8 hours. 

Not only that, but the chinese packs seem to offer identical reliablity figures. Since my cycles of my pack will be on the order of 20 per year... any warranty is pointless.

I'm basically only going with lifepo over NI-MH, Ni-cd etc because it weighs so much less and is actually cheaper . I would much prefer to use some 10 cent/WH ni-mh pack in my circumstances since the shelf life of the battery will dictate my useage far more.

even 20 recharging cycles a year is 8000 miles (suspected from my guesstimates).... I just can't suffer more than a 300lb battery pack... and I need the voltage from the many series cells to go highway speeds.

after 10-20 years when I throw the pack out... it may only have 300-500 cycles on it. It's almost a waste of my time in all honesty to try to test 100-150 cycles of my sample considering this, but I still want to help others if they need it.

Perhaps the lifepo's will last me my whole life... I hope so, but their shelf life doesn't seem that long under even ideal settings.

I wish I had other options in all honesty. Ni-MH def seems like a better option... if was half the price (like it should be). For this reason as I contemplate this more and more I've thought about making two of these cars and giving one to a family member that works 40-60 hours a week 30 miles away... 18k miles a year at even 300 miles/recharge is much more useful of lifepo's life cycle.

I think people forget just how long a 300 mile lifepo pack COULD last in theory... in any setting. at 10k miles a year (larger than even my 120 mile one way trips for college can rack up), you're talking about a mere 30 recharges annually... or over 20 years 600... out of a suspected 80% DOD of 1500

For instance David's 2000lb saturn, if he gets 125-150 miles out of the pack... it would take him something like 10 years of 12000-15000 miles a year to reach 1000 cycles... so given those circumstances (all lifepos) the lifetime of the VEHICLE dictates the battery's usablity, not how "performance over time" does.


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## JRP3 (Mar 7, 2008)

I will probably never need fast charging either, but to see the big battery picture you have to look beyond your own needs. For BEV's to really take off people either have to change their perspective on charge time requirements or fast charge has to become a reality. Since the technology exists to allow fast charging, and knowing the general publics' fear of running out of juice, the promise of fast charging will go a long way to promote the popularity of EV's.


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## Technologic (Jul 20, 2008)

JRP3 said:


> I will probably never need fast charging either, but to see the big battery picture you have to look beyond your own needs. For BEV's to really take off people either have to change their perspective on charge time requirements or fast charge has to become a reality. Since the technology exists to allow fast charging, and knowing the general publics' fear of running out of juice, the promise of fast charging will go a long way to promote the popularity of EV's.


Agreed but I think the idea of 300-400 mile ranges and 600k mileage battery lifetimes is enticing enough people wouldn't care for an occasional 3 hr charge (220 is everywhere afterall).

I think, in general, people are wide open to that kind of setting. We're not talking about 1200lbs of LA here and a recharge time of 8 hours with a range of 30 miles. Lithium could fairly simply and cheaply cause cars to be a one time purchase and never do ANY maintenance outside of shocks, greasing, and if you use a transmission (which I won't) occasional fluid checks. 

BLDC or AC motors negate any maintenance for the life of such a vehicle. The vehicle, controllers, etc could seemingly die faster than a set of lifepo's would. (unless you have a horribly designed circumstance like the Chevy volt which need recharged every day).

Just take that mitsubishi EV, 2000lbs, 16kwh, and seats 4 with a 80 mile range... even then you're pushing 150,000 miles before you have the replace the pack (and 16kwh is none-to-expensive either)

These reasons are also fairly solid ones for believing there won't ever be a grid recharging station. There's very little maintenance money in it.


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## JRP3 (Mar 7, 2008)

Ubiquitous fast charge stations would also allow one to carry a smaller battery pack. ICE's could carry 500 mile gas tanks, some do, but really 200 mile tanks are plenty large enough considering how many gas stations exist.
When you talk to most people, once you get past cost and performance concerns, the major argument against BEV's is battery life and recharge time. When those are no longer an issue there is no argument against BEV's. I think a battery pack that might outlive an EV is a good thing. No reason it can't be used in another, or in a home backup system or grid leveling.


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## Technologic (Jul 20, 2008)

JRP3 said:


> Ubiquitous fast charge stations would also allow one to carry a smaller battery pack. ICE's could carry 500 mile gas tanks, some do, but really 200 mile tanks are plenty large enough considering how many gas stations exist.
> When you talk to most people, once you get past cost and performance concerns, the major argument against BEV's is battery life and recharge time. \.


Like I said though, recharging stations would likely have to be something that came about AFTER a large movement to cars occured. Unless it was government ordered. The government definitely won't entice businesses to have those things set up anytime in the next few dozen years.

so in general selling a very large range pack is preferred for now.


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## david85 (Nov 12, 2007)

The only reason for fast charging is for the road trip part of our culture. Commuting an EV is a non issue by now, but the idea of not being able to just get in a car and go as far as you want is still a powerful one, even if that feeling of freedom is a lie.

Maybe it is a little soon to estimate how things will turn out, but the way things are headed right now, it doesn't look all that good for companies in canada and the united states. They just waited too long. Thats not to say that people like us can't find opportunities to make a living off of EVs if so inclined, but for one of the bigger companies to hit the big time......I just don't see how that can happen anymore.

Oh and technologic, mu saturn will probably be closer to 3000lbs when its done.......


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## Technologic (Jul 20, 2008)

david85 said:


> The only reason for fast charging is for the road trip part of our culture. Commuting an EV is a non issue by now, but the idea of not being able to just get in a car and go as far as you want is still a powerful one, even if that feeling of freedom is a lie.
> 
> Maybe it is a little soon to estimate how things will turn out, but the way things are headed right now, it doesn't look all that good for companies in canada and the united states. They just waited too long. Thats not to say that people like us can't find opportunities to make a living off of EVs if so inclined, but for one of the bigger companies to hit the big time......I just don't see how that can happen anymore.
> \


Well I certainly think it's a problem with the government here AND business special interests.

You're right it's a lie, and it's very imbedded in the culture of the older generations (I don't really think people in their 20s and younger feel that way about cars). 

We would never want to drive on a trip that's over 600 miles in a single sitting (and even then... probably with a 1-2 hour lunch). Younger people in general pack light, and when they go long distances it's by plane. 

The reason for my conversion and willingness to spend the time building it I think is a common thread many customers and people in the US/Canada would share. Completely engineering around maintenance and fuel costs.

Drop down 8-9k for a brand new EV, that seats 2 (I might in fact go 4 seats... just to prove I can do it and manage 200+ miles ) and never worry about it till I'm well out of law school and likely retiring.

That's the practical reason for it... and I think, if consumers saw that happening, they'd be all over it (couldn't make them fast enough).


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## david85 (Nov 12, 2007)

Any affordable EV that can seat 2 or more people and go 200+ miles per charge is something that no one could build fast enough to meet demand. Its already a very achievable prospect with lifepos and a streamlined composite platform, but I guess I'm preaching to the choir here.


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## JRP3 (Mar 7, 2008)

Indeed, but as I've mentioned before I think Tech's idea that they can be made for less than 10K, or even 20K, any time soon is unrealistic. I'd be quite glad to be proven wrong, but I'm not holding my breath.


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## ElectriCar (Jun 15, 2008)

JRP3 said:


> Indeed, but as I've mentioned before I think Tech's idea that they can be made for less than 10K, or even 20K, any time soon is unrealistic. I'd be quite glad to be proven wrong, but I'm not holding my breath.


The thing about pricing is a sales thing. A higher price is going to be reality as long as there's gassers around, in the near term anyway. There has to be a comparison done to show prospective buyers that paying more now is actually going to save money over time but the savings must be more than the vehicle price difference over probably a 5 year period. Otherwise lots of folks won't take the plunge.


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## Greenflight (Sep 13, 2007)

A higher price isn't just a marketing technique... It actually does cost more to build an electric car, at least in the low numbers that manufacturers are talking about right now. IMHO, the public isn't ready to support full scale production of electrics anyway. That's why homebuilts and conversions are so important. They help to show people what's possible. Right now, the average joe still thinks batteries are the limiting factor in electric cars. Get a few lithium conversions out there, and suddenly people start to realize how capable current tech really is.


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## Technologic (Jul 20, 2008)

JRP3 said:


> Indeed, but as I've mentioned before I think Tech's idea that they can be made for less than 10K, or even 20K, any time soon is unrealistic. I'd be quite glad to be proven wrong, but I'm not holding my breath.


I don't think that price will be seen from wide market evs for a long time.

Though 20k... the aptera's pricing was 23k .

At any rate, for my personal build project, <10k is def going to be doable.


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## JRP3 (Mar 7, 2008)

Technologic said:


> I don't think that price will be seen from wide market evs for a long time.


 Exactly my point.


> Though 20k... the aptera's pricing was 23k .


 The Aptera isn't a real car. We were talking regular 4 person, 4 wheels car that most people might buy. Also, Aptera has mentioned a wide range of prices, nothing is set in stone until they actually sell one.


> At any rate, for my personal build project, <10k is def going to be doable.


 We can't compare our one off builds to anything, unless you also calculate a realistic industry labor rate, as well as manufacturing overhead that a real company would have to deal with.


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## david85 (Nov 12, 2007)

JRP3 said:


> We can't compare our one off builds to anything, unless you also calculate a realistic industry labor rate, as well as manufacturing overhead that a real company would have to deal with.


Well actually, the standard industry rate could be considered one of he reasons why automakers are in such trouble right now. I think it would be financial suicide to try and manufacture anything on the assumption that you have to pay some one $40-$70/hour (including benefits) for labor. Theres no way you will succeed having to pay workers that much.


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## rfengineers (Jun 2, 2008)

david85 said:


> Well actually, the standard industry rate could be considered one of he reasons why automakers are in such trouble right now. I think it would be financial suicide to try and manufacture anything on the assumption that you have to pay some one $40-$70/hour (including benefits) for labor. Theres no way you will succeed having to pay workers that much.


For a business my size that $70/hour rate includes overhead. Things like rent, power, insurance, advertising, debt service, etc. etc. It's really tough to operate a business without some of those things.


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## JRP3 (Mar 7, 2008)

Yeah we don't have the luxury of paying slave wages in this country. But even figuring in a $20 per hour labor rate you aren't going to build a vehicle for $10k.


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## ElectriCar (Jun 15, 2008)

So without reading 15 pages I suspect prices are still falling since this thread started. Where are prices now and David have you gotten yours working yet?


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## Technologic (Jul 20, 2008)

JRP3 said:


> Yeah we don't have the luxury of paying slave wages in this country. But even figuring in a $20 per hour labor rate you aren't going to build a vehicle for $10k.


You could, in fact, once car importations from china are approved from crash testing.

South Korea (hyundai) and Chinese car manufacturers pay 150-300USD/mth...

This might sound low, but it's actually a fairly common wage in a lot of areas.

For instance Argentina and Uruguay (considered the two most industralized countries in south america), both have an average salary of around 300USD/month for anyone without over 4 years of college.

The major differences is the complete lack of federal regulations on wages, unemployment insurances, pensions, etc. 
Companies that don't adapt (and in this case move overseas) you're right, won't be successful. However, I don't think anyone believes GM or chrysler or Ford will possibly make a car that's worth anything to EVers for a long long time. 

That's definitely NOT the case with china. They are working very hard to get approved to sell cars here as well.

Even EV reselling parts in china (companies that aren't making these units themselves) are still 1/4th what people are paying for chargers here:
http://www.alibaba.com/product-gs/205242519/2000W_Electric_Vehicle_EV_Battery_Charger.html

If you want a $4000 EV new with more range than the chevy volt will have... china's already making them:
http://www.alibaba.com/product-gs/201098623/electric_car.html

These are not "slave wages" either. Many factory jobs and mining jobs in china afford them a lifestyle that was impossible a generation ago. Modern everything, city life, apartments. If you go to many provinces in china you can get a great meal at a small restaurant for $1USD. When that's the case (vs 14 times that on average in the US for the same meal), inflation hasn't reached you yet. 

In my opinion, they're living more at the turning point, while we're on our downward spiral. People with this kind of "wage morality" that associate china with slave labor need to reexamine their premises. They are in a far healthier, deflated, economy than the US and western countries are in. They are bridging technologies, developing most of the medicines we buy, etc. Anyone there can live well off, without struggling to find work, paying off massive debt, and not having enough money to power their homes. 

Also it is considered immoral to be in debt there. Cars are bought with cash over 95% of the time domestically. I think people in china would in general be offended by the idea that they are our slaves. I think most of them are genuinely of the attitude we americans had 80 years ago, that we were the "innovators"... while europe thought of us as cheap steel.

Cheers.


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## JRP3 (Mar 7, 2008)

Technologic said:


> If you want a $4000 EV new with more range than the chevy volt will have... china's already making them:
> http://www.alibaba.com/product-gs/201098623/electric_car.html


Come on man, that's a 35 mph NEV with a 60 mile range, not impressive. I'll bet the Volt can do 60 miles at 35 mph. We are talking about a real 4 passenger vehicle that can reach regular speeds with 200 mile range.


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## Technologic (Jul 20, 2008)

JRP3 said:


> Come on man, that's a 35 mph NEV with a 60 mile range, not impressive. I'll bet the Volt can do 60 miles at 35 mph. We are talking about a real 4 passenger vehicle that can reach regular speeds with 200 mile range.


lol my point was you take that car shove in $5000 of lifepos and you have your $10k dollar 200 mile range EV. 

China can do it... that's the point... and comparing a $47,000 car probably going just as far at 35mph as a $4000 or less car isn't helping much 

All of those cars are using floodies. At any rate... my point was I don't see how our massive inflationary spending practices can ever stop a deflated, unregulated economy like china from taking over all advancements.

I think it is impressive off lead acid in a 2000 lb 4 seater car to go 60 miles for $4000... isn't that half of what the average LA conversion costs people on this forum for a used car?

It's certainly not anything NEW, but it's certainly supposed to be in the "impossible range" that GM, Ford, etc denies is even possible for their company models.

I'm not promoting $4000 NEVs, though I think they do have a purpose. Nobody in the US is even thinking about making EVs for less than $40,000 in the next 10 years... unless aptera really does come in at 25k for their EV version.


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## Greenflight (Sep 13, 2007)

This is really comparing apples to oranges... A city car that goes 35 mph has absolutely nothing in common with what the average American wants. Even if it could go 80 mph, it appeals to a completely different market than a mid-size sedan.

I will agree that GM and Ford have been ridiculously discounting the possible range of electric cars... GM is, however, focusing on a different type of car. They're putting a lot more focus on the hybrid/gas part than the electric part, which is the wrong way to go about it IMO.


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## david85 (Nov 12, 2007)

JRP3 said:


> Yeah we don't have the luxury of paying slave wages in this country. But even figuring in a $20 per hour labor rate you aren't going to build a vehicle for $10k.


I was not referring to slave wages. All I was suggesting is not to limit your thinking to what detriot was able to accomplish (or fail to accomplish) in recent years. 



ElectriCar said:


> So without reading 15 pages I suspect prices are still falling since this thread started. Where are prices now and David have you gotten yours working yet?


No, my battery is in storage at the moment. More pressing matters have forced me to put the EV project on hold for a little while. Nothing major, just time consuming so it will get done just not as soon as we would like.


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## speculawyer (Feb 10, 2009)

Technologic said:


> They are bridging technologies, developing most of the medicines we buy, etc. Anyone there can live well off, without struggling to find work, paying off massive debt, and not having enough money to power their homes.


What planet is that China on?


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## JRP3 (Mar 7, 2008)

speculawyer said:


> What planet is that China on?


 Really. A friend of mine went to Beijing a few years ago and said it was a third world polluted hell hole and couldn't wait to get out. Probably seemed worse as he was in Tokyo just before going to China.


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## Technologic (Jul 20, 2008)

speculawyer said:


> What planet is that China on?


Have you tracked where your medical research is being done?

Many many many labs have moved to china 

Being polluted is about as relevant as saying Pittsburgh in 1919 was polluted.

Of course China is polluted in its major urban areas what do you expect? (though Beijing as an example is similar to using New Jersey as America's example).

I consider China's land prices, education prices, and food prices to be significantly low enough to assume that anyone in an urban area is what we could consider middle class by american standards.


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## Voltswagen (Nov 13, 2008)

Ahemmmm. 
I'm from New Jersey. I live in the Pine Barrens...one of the largest pine forests on the east coast. Not all of New Jersey is concrete.
Only the northern third.
I think we are missing a point here. We are assuming that a reliable EV couldn't be mass produced for less than 25K. But much of that assumption
lies with the cost of Chinese Lithium Batteries. What if those bats were manufactured here in the US? Which is just what has been recently proposed by Michigan's Govenor. The trick would be to keep the UAW out of the shop to keep the cost reasonable.
Roy


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## david85 (Nov 12, 2007)

It is most certainly possible to make low cost, high quality products in north america. What is lacking is the will to do it. I have no quarrel with the chinese, but if I had the option to buy something from here in canada instead I would gladly do so.


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## Technologic (Jul 20, 2008)

david85 said:


> It is most certainly possible to make low cost, high quality products in north america. What is lacking is the will to do it. I have no quarrel with the chinese, but if I had the option to buy something from here in canada instead I would gladly do so.


There's a stark problem getting through all of the fees, taxes, regulations, inspections, insurance, high wages... if you could do it with robots yeah maybe it could be as cheap ... I'd much prefer not importing if the price was the same.


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## david85 (Nov 12, 2007)

I think automation is certainly a good way to compete with low labor costs overseas. CNC machines have come down in price considerably in the last 10 years. With so many plants and tooling shops closing down, I can't help but wonder if I shouldn't go bargain hunting. My Dad (machinist among other things) has wanted to get some CNC equipment for a while and now might be the right time to go shopping.

Even a light duty CNC router table can do most of your composite prototyping and even mild metal machining. Make the Cad drawing, and upload to the machine to carve the plug for the mold. Its possible to do rapid prototyping this way, but this machine can also be programmed to replace a full time worker depending on the task at hand.

Instead of employees performing all the work, you have a few specialists running several machines. Like this it might even be possible to pay $40 or more per hour if you only have one or two guys like this. But paying that much for putting tires on one at a time is out of the question.


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## Technologic (Jul 20, 2008)

david85 said:


> Even a light duty CNC router table can do most of your composite prototyping and even mild metal machining. Make the Cad drawing, and upload to the machine to carve the plug for the mold. Its possible to do rapid prototyping this way, but this machine can also be programmed to replace a full time worker depending on the task at hand.
> 
> Instead of employees performing all the work, you have a few specialists running several machines. Like this it might even be possible to pay $40 or more per hour if you only have one or two guys like this. But paying that much for putting tires on one at a time is out of the question.


CAD drawings take like 30-40 seconds for most shapes (at least if you're any GOOD at it). A self taught philosophy/classics major like myself can pull you something extremely complicated in a few minutes ready for milling.

CNC table mills are soooo cheap now... and you can build your own (with routers for wood or plasma cutters for metal). Plasma cutters have also dropped a ton in price lately. Doing new body style cars could be incredibly fast with a router mill... you could cut a skeleton in a few hours for an entire car to lay glass over one off out of MDF or another cheap type of pressed fiberboard.

http://cgi.ebay.com/Desktop-KIT-CNC...5|66:2|65:12|39:1|240:1318|301:0|293:1|294:50

Also I really want a CNC lathe and have for YEARS. You could rapid one off anything in a few minutes... the most intricate tightest tolerance pieces in the world. Real shame I can't get one yet.... I'm sure I'd wear it out with ideas I haven't even thought of yet 

http://cgi.ebay.com/Mazak-Quick-Tur...5|66:2|65:12|39:1|240:1307|301:0|293:1|294:50


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## david85 (Nov 12, 2007)

I work with cad and it is possible to make drawings up fairly quickly depending on how complex they are. 2D is very fast to make, 3D takes longer, but the thing is I'm working off of AutoCad14 which is sadly out dated but more than adequate for designing railings. The 3D functions are tedious at best.

We are actually thinking of a machine a little larger, hoping for something in the range of 4' x 8' table and at least 10" Z axis. A machine like that could be used to make molds for all the different parts of a car (fenders, door shells, hood, and so on). Be it a more conventional 4 door like what I'm working on, or a streemlined arrow like you talk about.

This one is listed for $20k.

http://www.cncrouterstore.com/detailedinfo-5axisrouters-8932.html

Note that this is a 5 axis, not merely a 3 axis. Its practically a robot and could probably even be used for assembly of lighter parts if configured properly. Its also sturdy enough to mill high density plastic or even aluminum and not just modeling foam.

Eye candy....


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## Technologic (Jul 20, 2008)

david85 said:


> I work with cad and it is possible to make drawings up fairly quickly depending on how complex they are. 2D is very fast to make, 3D takes longer, but the thing is I'm working off of AutoCad14 which is sadly out dated but more than adequate for designing railings. The 3D functions are tedious at best.


Solidworks will forever make you regret learning 3D on autoCAD... autoCAD is almost 100% for 2D drawings IMO.



> We are actually thinking of a machine a little larger, hoping for something in the range of 4' x 8' table and at least 10" Z axis. A machine like that could be used to make molds for all the different parts of a car (fenders, door shells, hood, and so on). Be it a more conventional 4 door like what I'm working on, or a streemlined arrow like you talk about.
> 
> This one is listed for $20k.
> 
> ...


4"x8" is a pretty standard table size for small CNC routers. It's also very simple to build your own 3 axis CNC router table for about $2000

http://buildyourcnc.com/cnckit2.aspx

If you want a steel cutting one just make it out of steel and use a plasma cutter


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## david85 (Nov 12, 2007)

Is there a demo for solidworks? We tried BobCad and were left feeling shafted.

Building a router is still the prefered option, but my Dad is finding out that the cost of the servos and controls to often bring the cost closely in line with a turnkey operation (though build quality would be better). We're not giving up, but it can be frustrating at times.


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## Technologic (Jul 20, 2008)

david85 said:


> Is there a demo for solidworks? We tried BobCad and were left feeling shafted.
> 
> Building a router is still the prefered option, but my Dad is finding out that the cost of the servos and controls to often bring the cost closely in line with a turnkey operation (though build quality would be better). We're not giving up, but it can be frustrating at times.



There might be, but there's also student additions.

You can also torrent it which is free (ie. google Solidworks torrent)... which is what I think anyone learning those programs is forced to do by nature (programs like CATIA for car designs cost upwards of $20,000 dollars for a single version).

How can you make the money out of the program, before learning the program, which you need tons of money in order to practice on?

Note: it's not illegal to d/l torrents just reupload them 


Solidworks has tools for pretapped holes, bevels, extruding, gearings, and can also do limited animations (mostly for simple display purposes, but still useful).

You can also set up a series of construction plans (ie. how to animate the drawing or have a designer reconstruct the finished product of parts once it's all manufacturered)

http://www.youtube.com/watch?v=6BCgl2uumlI&feature=related

There's a rotary engine in SW


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## david85 (Nov 12, 2007)

Have to look into this. Thanks.


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## JRP3 (Mar 7, 2008)

Voltswagen said:


> But much of that assumption
> lies with the cost of Chinese Lithium Batteries. What if those bats were manufactured here in the US? Which is just what has been recently proposed by Michigan's Govenor. The trick would be to keep the UAW out of the shop to keep the cost reasonable.
> Roy


Since it's battery manufacturing, which could be used for anything, not just vehicles, UAW should have nothing to do with it.
http://internationalbatteryinc.com/ makes TS cells right here in PA. Try buying them. I contacted them looking for prices and asked some questions about their cells, (they show different C rates than TS), and all they said was they had not yet determined their distribution strategy. I'll try them again to see if anything has changed, but the sad truth is it will probably still be cheaper to import TS cells from China than buy them right here in our backyard.


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## Voltswagen (Nov 13, 2008)

You may be right JRP3. What I would not like to see happen is to trade our dependency on Foreign Oil for dependency on Foreign Batteries.
Roy


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## JRP3 (Mar 7, 2008)

I agree, but luckily with batteries you aren't dependent on a single resource to make them. Pick an element on the periodic table and someone is probably making a battery with it. Lithium seems to be the best at the moment but other chemistries may be as good or better.


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## bobgratonii (Jan 10, 2009)

the difference is that lithium can be recycled as petroleum cannot.


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## ElectriCar (Jun 15, 2008)

Technologic said:


> Also I really want a CNC lathe and have for YEARS. You could rapid one off anything in a few minutes... the most intricate tightest tolerance pieces in the world. Real shame I can't get one yet.... I'm sure I'd wear it out with ideas I haven't even thought of yet


Know what you mean. I worked on them back in the late 80's. If you've ever seen a guy run a manual mill or lathe and then you see one of these things go at it you can't help but be blown away. I've never ceased to be amazed at them, incredible speed and incredible accuracy all rolled into one.


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## Technologic (Jul 20, 2008)

Well it appears the battery has arrived, though at my other place of residence instead of here so I can't start testing till the weekend.

The business name is Sky Energy.

I recently found out that they are more than partially owned by the Chinese government... and have several factory locations.

http://www.skyenergy.com.cn 

I will be getting back to you all in another thread sometime this weekend once I can do some tests... the thread will start then I suppose.

At least it got there (family opened it and it's def there).

I bought a 3.7-5v PSU to charge it with that can do up to 48A continuous... should give me quite the range of charging options (it was only $30 from some guy's garage on ebay)


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## Voltswagen (Nov 13, 2008)

Let the testing begin!


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## TheAtomicAss (Feb 19, 2009)

Hello everyone, this is my first post on this forum, I was led here, specifically to this thread from the EcoModder forums. I can't wait to find out how batteries at this cost stack up. 



Technologic said:


> even 20 recharging cycles a year is 8000 miles (suspected from my guesstimates).... I just can't suffer more than a 300lb battery pack... and I need the voltage from the many series cells to go highway speeds.
> 
> after 10-20 years when I throw the pack out... it may only have 300-500 cycles on it. It's almost a waste of my time in all honesty to try to test 100-150 cycles of my sample considering this, but I still want to help others if they need it.
> 
> ...


I'm somewhat confused by your goal of discharging the pack fully before recharging it. From the graphs I have seen, (and of course I've forgotten to save them ), cycle life increases with lower DOD per cycle. The chart did not go very far, I think only out to 3,000 cycles on a 40% DOD test, but it never went below 90% total capacity on that chart. I forget who's batteries the chart covered, but it was <1000 cycles to 80% TC at 80% DOD.

Personally, my plans involve designing a car that can be driven as much off-grid as possible, (solar charging), so I'll be doing a lot of low-power "opportunity charging". 



JRP3 said:


> Since it's battery manufacturing, which could be used for anything, not just vehicles, UAW should have nothing to do with it.


Oh, some bright bulb will think up the UBW, I'm sure of it.


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## Greenflight (Sep 13, 2007)

Glad to see the battery got there OK... I'll be anxiously awaiting test results!


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## Technologic (Jul 20, 2008)

TheAtomicAss said:


> Hello everyone, this is my first post on this forum, I was led here, specifically to this thread from the EcoModder forums. I can't wait to find out how batteries at this cost stack up.


lol so much pressure... I will do my best to be accurate and diligent 



> I'm somewhat confused by your goal of discharging the pack fully before recharging it. From the graphs I have seen, (and of course I've forgotten to save them ), cycle life increases with lower DOD per cycle. The chart did not go very far, I think only out to 3,000 cycles on a 40% DOD test, but it never went below 90% total capacity on that chart. I forget who's batteries the chart covered, but it was <1000 cycles to 80% TC at 80% DOD.


My plans are to let the pack almost run out of range before recharging in an effort to help cycle life... at least that's my suspicion on how to get the most MILEAGE out of a pack. I assume that constant trickle charging and/or charging at only about 50% DOD will not be good ... since my range will be so substainal hopefully (shooting for 200+ miles on 1 charge) I've tried to think about how not to needlessly use up "cycles" so to speak.
I plan to test this a little bit... using the battery analyzer software I bought


> Personally, my plans involve designing a car that can be driven as much off-grid as possible, (solar charging), so I'll be doing a lot of low-power "opportunity charging".
> 
> 
> Oh, some bright bulb will think up the UBW, I'm sure of it.


Yeah initially I was wanting a solar panel and AC regen system... but after thinking about it it seemed waaaaay above my needs (or even usefulness considering my build plans)


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## RKM (Jun 9, 2008)

Techno,

Thanks for posting the link. These cells appear to be identical to TS, aside from colour and the posts appear a bit different. The specs and charts are the same. Are they related?

I've seen that TS cells come strapped in sets with backing plates to minimize swelling of the cell sides. Do you know if these do as well? 

Glad to hear that your test pack has arrived. Really, really hoping this is for real! $.35 per Wh... this makes LFP pretty attractive!

Rob


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## Technologic (Jul 20, 2008)

RKM said:


> Glad to hear that your test pack has arrived. Really, really hoping this is for real! $.35 per Wh... this makes LFP pretty attractive!
> 
> Rob


Well the test sample they sent for $1.25/AH or 39 cents per WH... so I'm pretty sure that price is the real price (35 cents for quantity) .

It is very attractive.

I will be able to offer real testing showing how many AH on graphs... done by computer once that tool arrives soon.

http://www.westmountainradio.com/Image/CBA2screen.jpg

AH over time... and shows the voltage as well as it drains...

I bought one of those testing modules... so I'll be able to graph cycles over previous cycles as well.


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## david85 (Nov 12, 2007)

Well thats it, Technologic (note how I spell the whole name) you are a celeberty of the web. Don't be a stranger now, and good luck.

My guess about sky energy is that thundersky is attempting to re invent itself with a new name and battery case color and scale up production significantly by undercutting the competition. Yes they do require strapping.

I'm almost afraid to say it, but this could be the begining of a price war in china over who has the right to sell LiFePO4 batteries. I heard from a contact in china that thundersky was given the highest favor of the chinese government of all the battery companies that were marketing lithium EV batteries.


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## John (Sep 11, 2007)

RKM said:


> Thanks for posting the link. These cells appear to be identical to TS, aside from colour and the posts appear a bit different. The specs and charts are the same. Are they related?


If those batteries are ThunderSky cells in disguise their spec's more closely resemble the LMP cells than the LFP cells which would be LiNiMnCoO2 rather than LiFePO4. I cannot see where the Sky Energy website states the battery chemistry.


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## Technologic (Jul 20, 2008)

John said:


> If those batteries are ThunderSky cells in disguise their spec's more closely resemble the LMP cells than the LFP cells which would be LiNiMnCoO2 rather than LiFePO4. I cannot see where the Sky Energy website states the battery chemistry.


.... I can't imagine anyone could make lithium cobalt batteries for that price?

Cobalt is still extremely expensive... I'm fairly certain they're lifepo's anyway... lithium polymer is what they were spec'd as.


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## John (Sep 11, 2007)

Technologic said:


> .... I can't imagine anyone could make lithium cobalt batteries for that price?
> 
> Cobalt is still extremely expensive... I'm fairly certain they're lifepo's anyway... lithium polymer is what they were spec'd as.


I don't think those are Cobalt cells. You can find the chemical make up here for the three different types http://www.thunder-sky.com/technical_en.asp?id=345&typeid=81&orderby=1


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## JRP3 (Mar 7, 2008)

John said:


> If those batteries are ThunderSky cells in disguise their spec's more closely resemble the LMP cells than the LFP cells which would be LiNiMnCoO2 rather than LiFePO4. I cannot see where the Sky Energy website states the battery chemistry.


They call them "LFP" cells, which sounds like LiFePo, just like Thundersky. In what way do you think the cell specs differ? Both show 3C constant, 10C max, same size and weight. The only difference I see is max charge is showing 3.6 for Sky Energy as opposed to 4.25 for TS, but that may just reflect the greater life cycle of keeping them under 3.8 which you should do with TS as well.


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## Technologic (Jul 20, 2008)

John said:


> I don't think those are Cobalt cells. You can find the chemical make up here for the three different types http://www.thunder-sky.com/technical_en.asp?id=345&typeid=81&orderby=1


They certainly have cobalt in them.

At any rate... I can't imagine they are cobalt cells... considering this is the "lower line" version of the cells they offer as well.


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## JRP3 (Mar 7, 2008)

Technologic said:


> They certainly have cobalt in them.


Why do you say that? The TS chart he linked doesn't show any cobalt in the LFP cells.


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## Technologic (Jul 20, 2008)

JRP3 said:


> Why do you say that? The TS chart he linked doesn't show any cobalt in the LFP cells.


I mean the LMP cells he thought these resembled.


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## JRP3 (Mar 7, 2008)

Technologic said:


> I mean the LMP cells he thought these resembled.


I think that must be a typo in the data sheet, because the element break down for the LMP cells doesn't show any Cobalt, and later on they identify the LMP cells as LiFMn2O4 as opposed to LiFNiMnCoO2 at the top of the page.


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## John (Sep 11, 2007)

The more I look into it the more I think the remarkable dimensional and weight similarities between the range of Sky Energy and ThunderSky LMP cells are just coincidental.


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## TheAtomicAss (Feb 19, 2009)

Technologic said:


> My plans are to let the pack almost run out of range before recharging in an effort to help cycle life... at least that's my suspicion on how to get the most MILEAGE out of a pack. I assume that constant trickle charging and/or charging at only about 50% DOD will not be good ... since my range will be so substainal hopefully (shooting for 200+ miles on 1 charge) I've tried to think about how not to needlessly use up "cycles" so to speak.
> I plan to test this a little bit... using the battery analyzer software I bought
> 
> 
> Yeah initially I was wanting a solar panel and AC regen system... but after thinking about it it seemed waaaaay above my needs (or even usefulness considering my build plans)


Did you order just one sample, or a few? Just 2 batteries, supposing they're good, would give you enough to sample 80-90% DOD vs. say, 25% DOD. It would take a long time to do 1,500 cycles though. 

Also, I've never seen any charts that go beyond the 80% TC figure... Has anyone ever charted a battery into complete uselessness that you're aware of? I'd think that even once you reached the end of the manufacturers stated cycle life, you'd still have some real-world useful life left.

I've heard that trickle-charging is bad for Lithium. I've figured that into my design, and the panels will basically be shutoff/used for other things (like air-conditioning), when the charge level is above say, 95%.


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## Technologic (Jul 20, 2008)

TheAtomicAss said:


> Did you order just one sample, or a few? Just 2 batteries, supposing they're good, would give you enough to sample 80-90% DOD vs. say, 25% DOD. It would take a long time to do 1,500 cycles though.
> 
> Also, I've never seen any charts that go beyond the 80% TC figure... Has anyone ever charted a battery into complete uselessness that you're aware of? I'd think that even once you reached the end of the manufacturers stated cycle life, you'd still have some real-world useful life left.
> 
> I've heard that trickle-charging is bad for Lithium. I've figured that into my design, and the panels will basically be shutoff/used for other things (like air-conditioning), when the charge level is above say, 95%.


I certainly won't test 1500 cycles unfortunately. It's unlikely in 10 years I will put more than 600 cycles into the batteries . 80-90% DOD is what I mean by "discharging all of the way" since most lithium batteries have a sharp voltage drop starting around there and it is best not to discharge them into that voltage drop.

I plan to only test maybe 50 cycles as best I can... anything more than that will be a test of my patience... but it will be nice to test high amperage charging as well (0.5C charging)...

Cheers.


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## JRP3 (Mar 7, 2008)

John said:


> The more I look into it the more I think the remarkable dimensional and weight similarities between the range of Sky Energy and ThunderSky LMP cells are just coincidental.


Someone else thinks they are TS cells, he says his last order of TS cells were blue cases and that he's been getting the same prices as quoted to Techno. Maybe it is TS trying to reinvent themselves. Tech did you ever think to ask them if they are the same as TS? ThunderSky to Sky Energy certainly sounds like a possible re-branding.


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## Technologic (Jul 20, 2008)

JRP3 said:


> Maybe it is TS trying to reinvent themselves. Tech did you ever think to ask them if they are the same as TS? ThunderSky to Sky Energy certainly sounds like a possible re-branding.


It certainly may be...

I intend to go to china in the next 8 months and will probably visit their factory when I do.

I can ask if they are related to Thundersky though through my contact now.


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## jlubimir (Feb 12, 2009)

speculawyer said:


> Does this mean that the US makers will just get killed by China in the end? Will Valence, Enerdel, A123, and any others all go down in view of cheap competition from China?


 
I spoke to Valence this week (finally), and their batteries are in fact made in China. Not sure who is actually doing their manufacturing, although it is surely not one of the usual lower cost Chinese manufacturers (at least based upon their "list" price. (about $2,600 for their XP-27, 138Ah model.)


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## david85 (Nov 12, 2007)

jlubimir said:


> I spoke to Valence this week (finally), and their batteries are in fact made in China. Not sure who is actually doing their manufacturing, although it is surely not one of the usual lower cost Chinese manufacturers (at least based upon their "list" price. (about $2,600 for their XP-27, 138Ah model.)


Good to know. As I've said in the past, the chinese are perfectly capable of making good quality products. Would be interesting to know who their jobber is, but I suspect valence is making a healthy profit margin on their prices.


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## ElectriCar (Jun 15, 2008)

Alright, what's up Techno? You said you'd have some testing done this weekend. We're all ears or eyes I should say...


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## Technologic (Jul 20, 2008)

ElectriCar said:


> Alright, what's up Techno? You said you'd have some testing done this weekend. We're all ears or eyes I should say...


Currently law school has kept me busy and I didn't have time to head to pick up the battery analyzer yet from the PO box.

Just give me till this weekend and I should have time to upload pics and some prelim testing

Initial power testing looked fine... charged to 3.25v (according to my voltage meter), that's all I've had time to do.


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## grayballs (Aug 27, 2008)

Anybody, other than me, having trouble making that sky energy link work? It sends me to an alibaba search that locks up


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## Technologic (Jul 20, 2008)

grayballs said:


> Anybody, other than me, having trouble making that sky energy link work? It sends me to an alibaba search that locks up


Try copying and pasting it... not sure why it did that but here's a relink:
http://www.skyenergy.com.cn/


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## JRP3 (Mar 7, 2008)

Their home site is sketchy sometimes, I usually have better luck with the Alibaba site:
http://skyenergy.en.alibaba.com/


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## Grant_NZ (May 28, 2008)

Probably a silly question but despite the cost, a 200Ah battery is obviously better to have than 90AH?


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## Technologic (Jul 20, 2008)

Grant_NZ said:


> Probably a silly question but despite the cost, a 200Ah battery is obviously better to have than 90AH?


Pretty much the same I suppose just multiple cells in one package?

Less packages = less wiring... so perhaps that's "better"


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## grayballs (Aug 27, 2008)

JRP3 said:


> Their home site is sketchy sometimes, I usually have better luck with the Alibaba site:
> http://skyenergy.en.alibaba.com/


 
Thanks,,,, I don't know why I couldn't get there from the other link. Nothing I tried seemed to work.


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## JRP3 (Mar 7, 2008)

Technologic said:


> Pretty much the same I suppose just multiple cells in one package?


 I don't think that's how the larger prismatic cells are made, since you'd then have cell balancing issues within a single battery. I think it's just a physically larger wrapping of cell material to create a single larger cell. http://www.youtube.com/watch?v=HJrNCjVS0gk


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## david85 (Nov 12, 2007)

JRP3 said:


> I don't think that's how the larger prismatic cells are made, since you'd then have cell balancing issues within a single battery. I think it's just a physically larger wrapping of cell material to create a single larger cell. http://www.youtube.com/watch?v=HJrNCjVS0gk


There is no limit to how many cells you can wire in parallel without having to use balancing. Its only in series connections that BMS is required. I'm guessing the documentary clip shows the making of a high voltage module, hence the need for a BMS connection to every cell.


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## JRP3 (Mar 7, 2008)

So are you saying that a single 100 Ah 3.2 volt prismatic is a bunch of cells in parallel?


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## Technologic (Jul 20, 2008)

JRP3 said:


> So are you saying that a single 100 Ah 3.2 volt prismatic is a bunch of cells in parallel?


no but a 3.2v x 200ah battery probably _is_ two cells.


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## speculawyer (Feb 10, 2009)

There certainly are cheap LiFePO4s out there. Here is a pre-made 72V pack made of 24 90AH LiFePO4s for $2600:
http://www.alibaba.com/product-free/103327355/LFP_72V_Electric_Vehicle_Battery.html

By my calculations, that is about $0.38/watt-hour for a pack that supposedly comes with a BMS. (Although I don't see any BMS in that picture they have there.)

The big problem is trust . . . can one really trust these fly-by-night outfits?


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## Technologic (Jul 20, 2008)

speculawyer said:


> The big problem is trust . . . can one really trust these fly-by-night outfits?


Well sky energy certainly has been around awhile as far as I can tell.

We'll see how the testing goes when I'm able to get really "dirty" with it soon.


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## JRP3 (Mar 7, 2008)

Those packs look like they're made up with Seiden cells, I don't think Khadra actually makes the cells.
http://www.khadrasolar.com/


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## John (Sep 11, 2007)

Grant_NZ said:


> Probably a silly question but despite the cost, a 200Ah battery is obviously better to have than 90AH?


I think it makes the most economic sense to buy the minimum battery able to fulfil your needs considering that there is probably a time based deterioration of the batteries as well as a use based deterioration. Even discounting time based deterioration tying up huge amounts of money for range you don’t need and longevity you might not benefit from for 10 years wouldn't be financially prudent.

The voltage you choose (along with motor characteristics, gearing etc.) will determine the maximum speed of the vehicle and will it self be determined by the number of cells. Having a high top speed may seem unimportant but the vehicle that tops out at 70mph is going to have a lot less acceleration available at 60mph for passing than one that tops out at 90mph. It’s good to have head room even if you don't intend to use it. 

The maximum and continuous amperage you can draw from your pack will be determined largely by the size of the cells (and cell type). This coupled with the limitations of your controller determines available acceleration (along with motor characteristics, gearing etc.). The 90Ah batteries should be more than up to the task. At 3C continuous and 10C peak that is 270A continuous and 900A peak. It would be good to establish allowable peak duration from the cell manufacturer. A 10 or 15 second peak would be more than enough for accelerating away from the lights but you would have to fall back to your continuous rating for climbing a hill.


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## speculawyer (Feb 10, 2009)

JRP3 said:


> Those packs look like they're made up with Seiden cells, I don't think Khadra actually makes the cells.
> http://www.khadrasolar.com/


Yeah, I think these guys just put together cells, add a simple BMS, and wrap them up for delivery. 

At these prices, anyone that owns an NEV with dead or dying lead-acid batteries should covert to these LiFePO4 packs. I've seen the specialized deep-cycle lead-acid batteries for NEVs going for over $200 per 12V battery. For a 72V pack that would be $1350 + shipping. You might as well pay twice that and replace them with a set of LiFePO4s that will last probably longer than the NEV, never need maintenance, reduce the weight load, and give you a longer range, etc.


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## dimitri (May 16, 2008)

> The 90Ah batteries should be more than up to the task.


Assuming we are discussing a typical car, 2000-3000 Lb, and assuming one is investing in Lithium to have a range of 50-100 miles, and assuming typical DC system voltage 144-156 V, 90Ah cells are not big enough. However, 200 Ah cells maybe a bit overkill IMHO, again with all above assumptions. 160Ah seems to be a good medium for a car, these are very popular among current Lithium conversions, mine included.

Don't forget that although LiFePo4 is half the weight of Lead Acid, but it still takes about the same volume in the car and still a challenge to mount all the cells and have some seating room left.

Look at current Lithium EVs on EV album. I especially like the Hyundai with 260Ah cells and no room left for people  These would be good for S10 pickup though...


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## speculawyer (Feb 10, 2009)

dimitri said:


> Assuming we are discussing a typical car, 2000-3000 Lb, and assuming one is investing in Lithium to have a range of 50-100 miles, and assuming typical DC system voltage 144-156 V, 90Ah cells are not big enough. However, 200 Ah cells maybe a bit overkill IMHO, again with all above assumptions. 160Ah seems to be a good medium for a car, these are very popular among current Lithium conversions, mine included.
> 
> Don't forget that although LiFePo4 is half the weight of Lead Acid, but it still takes about the same volume in the car and still a challenge to mount all the cells and have some seating room left.


Brian's beautiful Honda S2000 also uses 45 LFP-160AH TS batteries.
http://s2kev.blogspot.com/

LiFePO4 should be a little bit smaller in volume. But it would be nice if they were smaller still. For cars designed as EVs, they'll use the space in the car more efficiently. (Instead of the big empty gaps like the one from the gas tank.)


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## Voltswagen (Nov 13, 2008)

My plan, if these batteries test well, is to purchase 60 of these 3.2v 90ah
Lithiums. Then create 30 - 2 battery parallel strings. Those strings in series would yield 96 volts at 180ah. That would be sufficient for my 77 Beetle Convertible. 
My current system is 120v LA. batteries weighing 945lbs. 
By installing Lithium not only would I avoid the dreaded voltage sag but also lose 550lbs of weight. I realize that I am dropping 24 volts of power but the weight loss should result in similar or possibly even better acceleration. And of course the much extended range.


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## JRP3 (Mar 7, 2008)

Voltswagen said:


> My plan, if these batteries test well, is to purchase 60 of these 3.2v 90ah
> Lithiums.


I can't see why you wouldn't use the 100ah cells, same weight, and if they are the same as TS cells the only dimensional difference is they are 1/4 inch thicker.


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## Technologic (Jul 20, 2008)

JRP3 said:


> I can't see why you wouldn't use the 100ah cells, same weight, and if they are the same as TS cells the only dimensional difference is they are 1/4 inch thicker.


I personally am going with 90AH cells because the higher voltage is more useful than more AH (a 500-600lb car shouldn't pull over 2C continuous even up hills)

We'll see how the discharging goes.

I unfortunately can't straight test anything but 0.5C discharging (on a computer anyway), so the 2C stuff will be dummy loaded and shorted (800w of heat being discharged out of a heatsink on the resistor) I can read the voltage sag hopefully this way.

Luckily I have a lot of this gear from my speaker designing (and amplifier designing) days.


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## Grant_NZ (May 28, 2008)

John said:


> I think it makes the most economic sense to buy the minimum battery able to fulfil your needs considering that there is probably a time based deterioration of the batteries as well as a use based deterioration....




Deterioration - an issue I didn't think of but it does prompt putting a system into place make sure the 80% DOD is never exceeded. I would hate to spend 30K NZ in a battery pack to have it last only 2 years, this an available piece of technology I take it?



John said:


> The voltage you choose (along with motor characteristics, gearing etc.) will determine the maximum speed of the vehicle and will it self be determined by the number of cells.


 

My original calculations were based on a small pickup but has changed as the business will pay for the running costs of any vehicle required for haulage of materials, now back to the drawing board as to what the donor will be... 




John said:


> Having a high top speed may seem unimportant but the vehicle that tops out at 70mph is going to have a lot less acceleration available at 60mph for passing than one that tops out at 90mph. It’s good to have head room even if you don't intend to use it.


Yet again another obvious parameter overlooked 



John said:


> The maximum and continuous amperage you can draw from your pack will be determined largely by the size of the cells (and cell type). This coupled with the limitations of your controller determines available acceleration (along with motor characteristics, gearing etc.). The 90Ah batteries should be more than up to the task.


 
Hmmm 90Ah maybe ok elsewhere but we live in a country where hill climbs are a regular part of our journey. Originally I calculated 200Ah - 204V pack; 64 Lithium Ion batteries at 3.2V, about 30K's worth a year ago.





John said:


> At 3C continuous and 10C peak that is 270A continuous and 900A peak. It would be good to establish allowable peak duration from the cell manufacturer. A 10 or 15 second peak would be more than enough for accelerating away from the lights but you would have to fall back to your continuous rating for climbing a hill.


I decided not to go cheap and use an AC system and purchase quality parts but thank you for the extra information... 

now I have more to calculate when deciding what donor vehicle to purchase.. sigh


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## JRP3 (Mar 7, 2008)

Technologic said:


> I personally am going with 90AH cells because the higher voltage is more useful than more AH (a 500-600lb car shouldn't pull over 2C continuous even up hills)


I don't see where you have to trade off voltage for AH in this case. If the cells weigh the same there is no weight penalty for the extra 10 AH so you can use the same number of cells for the same voltage. I'm not sure of the size of the Sky Energy cells but the 100 AH TS cell is only 1/4 inch thicker than the 90, all other dimensions the same. If you are really tight on volume maybe the 1/4 inch makes a difference but in most cases I wouldn't think it would matter.


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## Voltswagen (Nov 13, 2008)

I would consider the 100ah bats if the price were similar. The slight size difference doesn't matter to me.


----------



## ElectriCar (Jun 15, 2008)

JRP3 said:


> I don't see where you have to trade off voltage for AH in this case. If the cells weigh the same there is no weight penalty for the extra 10 AH so you can use the same number of cells for the same voltage. I'm not sure of the size of the Sky Energy cells but the 100 AH TS cell is only 1/4 inch thicker than the 90, all other dimensions the same. If you are really tight on volume maybe the 1/4 inch makes a difference but in most cases I wouldn't think it would matter.


He said he chose the 90's due to their being the most popular size thus better pricing or something like that.


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## JRP3 (Mar 7, 2008)

Well that was his initial thought but someone else mentioned that's not the case.


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## Technologic (Jul 20, 2008)

JRP3 said:


> Well that was his initial thought but someone else mentioned that's not the case.


I'll find out about price difference if any for the 100ah... if the price is the similarly priced $1.1/AH then I probably will use them to save a tiny amount of overall space (plus round numbers are nice). 

the TK90AHA is their most often sold... followed by the 160AHA, so I assumed from the get go that the price would be somewhat cheaper.

I know, with a decent sized order (500 pcs) I could see $1/AH for the 90AHA a further 9% price reduction, or $0.31/WH.

Beyond that I haven't asked about different sizes.


----------



## speculawyer (Feb 10, 2009)

Technologic said:


> I know, with a decent sized order (500 pcs) I could see $1/AH for the 90AHA a further 9% price reduction, or $0.31/WH


At that price, the cost of the 16Kwh pack for the Chevy Volt is less than $5K. Considering that each one will come with a $7.5K subsidy from the government, someone has to be able to make a profitable series-hybrid by now since the subsidy more than covers the battery cost.


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## JRP3 (Mar 7, 2008)

The Volt isn't using Thundersky technology. I can't remember what battery they are using,(LG Chem?), but I think it's rated at a higher C rate than the TS type cells and have greater density than TS cells.


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## Technologic (Jul 20, 2008)

speculawyer said:


> At that price, the cost of the 16Kwh pack for the Chevy Volt is less than $5K. Considering that each one will come with a $7.5K subsidy from the government, someone has to be able to make a profitable series-hybrid by now since the subsidy more than covers the battery cost.


Don't count on it... I mean my car will cost less than the subsidy for the whole build... but just don't count on any car company in the next 10 years making any EV under 20k dollars... (more than likely less than 30k is impossible to see... too much profit in it.)


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## david85 (Nov 12, 2007)

JRP3 said:


> The Volt isn't using Thundersky technology. I can't remember what battery they are using,(LG Chem?), but I think it's rated at a higher C rate than the TS type cells and have greater density than TS cells.


a123 cells. I think the C rate is in the mid 30s. But thats expected with cells that are spiral wound in a metal can (unless they are REALLY low quality).


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## JRP3 (Mar 7, 2008)

david85 said:


> a123 cells. I think the C rate is in the mid 30s. But thats expected with cells that are spiral wound in a metal can (unless they are REALLY low quality).


Actually it is LG http://blog.mlive.com/svengustafson/2009/02/gm_exec_on_korean_battery_make.html
A123 was in the running but apparently didn't make the cut. Back to my original point, higher C rate cells are more expensive than TS type cells, so comparing the two prices is not an apples to orange comparison.


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## coryrc (Aug 5, 2008)

John said:


> I think it makes the most economic sense to buy the minimum battery able to fulfil your needs considering that there is probably a time based deterioration of the batteries as well as a use based deterioration.


I spent five hours on chat with a Sky Energy representative. Here's what she says:

Battery life when used for 300 cycles/yr to 70% is 3-5 years.
Yearly capacity degradation is 6-7%.


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## JRP3 (Mar 7, 2008)

3-5 years is a huge difference and doesn't speak well to the accuracy of their information. Did you ever ask them if they are connected to Thunder Sky?


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## ElectriCar (Jun 15, 2008)

Ouch! 3-5yrs? Not good.


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## Technologic (Jul 20, 2008)

coryrc said:


> I spent five hours on chat with a Sky Energy representative. Here's what she says:
> 
> Battery life when used for 300 cycles/yr to 70% is 3-5 years.
> Yearly capacity degradation is 6-7%.


That's a tad more than I predicted, but not wholly unexpected.

That's a rather large yearly degradation... I was expecting 2-3%


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## Technologic (Jul 20, 2008)

ElectriCar said:


> Ouch! 3-5yrs? Not good.


Well 3-5yrs at 300 cycles/yr = 900-1500 cycles of discharging charging... even with a 100mile range that's 100-150,000 miles in a period of only 5 years.

I'm more concerned if 6-7% raw degredation is accurate.


----------



## ElectriCar (Jun 15, 2008)

Technologic said:


> Well 3-5yrs at 300 cycles/yr = 900-1500 cycles of discharging charging... even with a 100mile range that's 100-150,000 miles in a period of only 5 years.
> 
> I'm more concerned if 6-7% raw degredation is accurate.


Yea but that's a chunk of money for that many miles don't you think? I've already got 1000 miles on my ev that was finished 12/1 and it's been in various shops for probably a month out of that time getting painted, upholstery etc and this is with a slow economy.

I plan on putting a ton of miles on it eventually. I'm a contractor who hits the road a lot to look at jobs etc so I'm not getting too much out of it at the moment. The other day I put 60 miles on it and could have went more had I needed to.

One thing I forgot, what is the pack KW were speaking of and if these numbers are applied to a pack of 45 160AH batteries, what would that translate to for a lifetime mileage wise. That's what I'm thinking of switching to or 120ah. 

Tomorrow for example I have a trip to make that round trip is 35 miles and is all interstate. I can't make that leap at this time for fear of not making it back! My ultimate range would be about 60-65 miles @ 90% interstate.


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## Technologic (Jul 20, 2008)

JRP3 said:


> 3-5 years is a huge difference and doesn't speak well to the accuracy of their information. Did you ever ask them if they are connected to Thunder Sky?


I just asked and was told:
"no , we are isolated with thunder sky"

apparently some of thunder sky's batteries are purchased from sky energy (larger format ones)


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## Technologic (Jul 20, 2008)

ElectriCar said:


> Yea but that's a chunk of money for that many miles don't you think? I've already got 1000 miles on my ev that was finished 12/1 and it's been in various shops for probably a month out of that time getting painted, upholstery etc and this is with a slow economy.


No doubt it's a bit on the disappointing side if 6-7% yearly is accurate.

I don't think 1500 cycles over a period of 5 years is totally crazy low though... I think if you see over 1000 (get to use that much before tossing them) in a LFP, you got your money's worth.

I was hoping for 10 yrs of minimal cycles annually though (like 30-40 recharges a year).


----------



## Technologic (Jul 20, 2008)

I also went ahead and asked, and they didn't know the loss of capacity annually off of their information... but I was told:

"for the first year , the capacity will not lose or lose little , then it will lose slowly , I don't know it very clear , I will ask the engineer as soon as he come back"

So hopefully we'll have "some" idea (6-7% would be appalling high after researching general chemistry data)... we can at least have an idea of their "claim".

Also sky energy had something to do with thundersky at some point, but as broken away completely via government subsidies or something.


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## coryrc (Aug 5, 2008)

JRP3 said:


> 3-5 years is a huge difference and doesn't speak well to the accuracy of their information.


LiFePO4 in its most basic form was invented in 1996. The modern chemistries haven't been around long enough to make predictions any better than that. Any tighter prediction would be a lie.


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## Technologic (Jul 20, 2008)

coryrc said:


> LiFePO4 in its most basic form was invented in 1996. The modern chemistries haven't been around long enough to make predictions any better than that. Any tighter prediction would be a lie.


I can't seem to find any data that suggest Lifepo degrades faster than Li-ion... in fact it should degrade far slower (between 20-40% less quickly).

You can make predictions without the time line... by simply mapping 1-3 years of degradation, you could be quite close to guessing at the overall degradation of the battery annually.

After the first year it is supposed to have a higher energy density than li-ion... which has been proven to last 10+ years under even heavy use situations


----------



## JRP3 (Mar 7, 2008)

The modern chemistries have been around for more than 3 years, so they should have more accurate information than "between 3-5 years".


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## coryrc (Aug 5, 2008)

Technologic said:


> So hopefully we'll have "some" idea (6-7% would be appalling high after researching general chemistry data)... we can at least have an idea of their "claim".


Don't the Co/Mn chemistries lose up to 20% per year? (depends on temperature and SoC, of course)


----------



## coryrc (Aug 5, 2008)

JRP3 said:


> The modern chemistries have been around for more than 3 years, so they should have more accurate information than "between 3-5 years".


I didn't give them discharge rates, time spent at various SoC, etc. so it was just a rough estimate.


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## JRP3 (Mar 7, 2008)

coryrc said:


> I didn't give them discharge rates, time spent at various SoC, etc. so it was just a rough estimate.


True, those are important variables, but at 70% discharge I'd expect better than 300 cycles per year for 3 years under most circumstances.


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## Technologic (Jul 20, 2008)

coryrc said:


> Don't the Co/Mn chemistries lose up to 20% per year? (depends on temperature and SoC, of course)


No... they lose something like 2-5% of their total fully charged capacity annually....

Are you talking about compounding discharge losses? because that could change things for the better...

like if it lost 6% a year at 90AH... would be 84.75AH than lost 6% of 84.75AH etc.

edit: after double checking I guess some of the older Li-ions lost 20% of their capacity if stored at full charge all of the time.

"When stored at 40%–60% charge level, the capacity loss is reduced to 2%, 4%, 15% at 0, 25 and 40 degrees Celsius respectively."


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## coryrc (Aug 5, 2008)

Technologic said:


> You can make predictions without the time line... by simply mapping 1-3 years of degradation, you could be quite close to guessing at the overall degradation of the battery annually.


Depends on the failure mode; it is my impression lead-acid batteries will operate with very small degradation until the acid eats away enough to greatly increase the internal resistance, and this happens at about 7-8 years on standard batteries predominantly kept near full charge.



Technologic said:


> After the first year it is supposed to have a higher energy density than li-ion... which has been proven to last 10+ years under even heavy use situations


Which Li-Ion batteries last 10+ years?


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## Technologic (Jul 20, 2008)

coryrc said:


> Which Li-Ion batteries last 10+ years?


I just quoted data... ones that aren't exposed to extremely high storage temps and leaving them fully charged while storing.

2%-5% is relatively normal for "most" air temperature ranges if the battery is stored at less than 100% capacity.

If the battery is left partially discharged for long periods it will decay at a fairly constant 5%/year rate (this is compounded as well.. not 5% of the initial energy capacity)


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## coryrc (Aug 5, 2008)

Technologic said:


> No... they lose something like 2-5% of their total fully charged capacity annually....


From http://en.wikipedia.org/wiki/Lithium-ion_battery#Shelf_life

"At a 100% charge level, a typical Li-ion laptop battery that is full most of the time at 25 °C or 77 °F will irreversibly lose approximately 20% capacity per year. "
EDIT: missed your post, you posted this above.



Technologic said:


> Are you talking about compounding discharge losses? because that could change things for the better...


They didn't say.


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## Technologic (Jul 20, 2008)

coryrc said:


> So it depends on many factors, but millions of laptops with batteries that only last a few years are very strong evidence for short lifespans.
> 
> 
> They didn't say.


a lithium battery in a laptop and in a car are vastly different environments... 

Likewise lithium polymers have a far different characteristic...

LiFePO4 cells have lower voltage and energy density than normal Li-ion cells. But please note that:


After 1 year of use a LiFePO4 cell typically has approximately the same power density as a normal Li-ion cell.
After about 1+ years of use a LiFePO4 cell has a _higher_ power density than a normal Li-ion cell.
Clearly under normal circumstances a car won't be stored at maximum capacity would it?

Maybe so, but not in my application.

It seems that 6-7% is a very "liberal" estimate... since I can't seem to find any data suggesting that at room temp it drops over 4%/annually for lithium polymer.

As with all batteries it's a poor choice to store them for long periods fully charged... lead acids react the same way.

Constantly using them will shift this data around into unpredictable territories. It clearly will be heavily application dependent (and treatment dependent) just like with lead acid.


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## JRP3 (Mar 7, 2008)

Technologic said:


> As with all batteries it's a poor choice to store them for long periods fully charged... lead acids react the same way.


What? Lead acid lasts longest when kept fully charged, lower charge leads to sulfation.


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## coryrc (Aug 5, 2008)

Technologic said:


> Clearly under normal circumstances a car won't be stored at maximum capacity would it?


Some will keep at maximum capacity for a while (charge at night, many hours will be spent at full charge, sleeping in on the weekends, etc.) Also think about people using them at elevated temperatures in warm regions (AZ, TX, etc) or the desert.



Technologic said:


> It seems that 6-7% is a very "liberal" estimate


True, I asked for safe numbers.



Technologic said:


> As with all batteries it's a poor choice to store them for long periods fully charged... lead acids react the same way.


Not really, if you leave lead acid less than close-to-full they'll harden the plates. And flooded Ni-Cd and NaS don't care (not sure about NiMH...)



Technologic said:


> Constantly using them will shift this data around into unpredictable territories. It clearly will be heavily application dependent (and treatment dependent) just like with lead acid.


QFT


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## Technologic (Jul 20, 2008)

JRP3 said:


> What? Lead acid lasts longest when kept fully charged, lower charge leads to sulfation.


if you remove the electrolyte, otherwise LA will discharge extremely quickly if left on a shelf.

Lower charges in LA are always bad of course.

I think I'm going to have to employ a light solar A/C system of some kind in an insulated battery area... I'd rather get 10+ yrs ... and A/C is simple/cheap enough. Simply run a small AC system over the batteries? 

I dunno I'll have to look into the power of a 100-120w small AC system to keep a highly insulated area cool enough...

25C is a monstrous difference in damage done than storing at full charge at 40C (summer).

Though in my application I will probably keep it at 50-80% 95% of the time, it still seems a bit on the safe side to set up a small A/C area so they don't boil constantly for 6+ mths a year


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## JRP3 (Mar 7, 2008)

I wonder what they consider fully charged to be? 4.25 is theoretically fully charged but recommendations are to not go above 3.8 or so.


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## Technologic (Jul 20, 2008)

JRP3 said:


> I wonder what they consider fully charged to be? 4.25 is theoretically fully charged but recommendations are to not go above 3.8 or so.


I honestly don't know... 3.27v is what my battery read after about 2 hours sitting... it was measuring about 3.9v right after charging.


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## coryrc (Aug 5, 2008)

JRP3 said:


> I wonder what they consider fully charged to be? 4.25 is theoretically fully charged but recommendations are to not go above 3.8 or so.


Can't measure SoC from just voltage.


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## JRP3 (Mar 7, 2008)

Technologic said:


> I honestly don't know... 3.27v is what my battery read after about 2 hours sitting... it was measuring about 3.9v right after charging.


Sounds as if it wasn't charged long enough, or maybe it needs to see higher voltage when charging, how high does it read on the charger?


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## Technologic (Jul 20, 2008)

JRP3 said:


> Sounds as if it wasn't charged long enough, or maybe it needs to see higher voltage when charging, how high does it read on the charger?


3.9v-4v is the charging I was charging at (recommended to charge at max 3.9v).

nominal voltage is supposed to drop to 3.2v or so... it's more likely I overcharged it than undercharged it as well... it was taking 20amps for over 5 hours.

I'll know in 2 days when I'm able to discharge it where the AH is so I can adjust, but 3.2xxx volts sounds correct for the nominal voltage after some time.

If the battery was really 3.7v or higher at charging, the battery would (higher nominal voltage) actually be a 333wh cell... or 0.29/WH in price.

I can't know until I discharge it via my battery analyzer.


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## Technologic (Jul 20, 2008)

on a totally seperate note ... fully refrigerating a battery compartment is actually relatively cheap for summer longevity.

With decent insulation one can expect their battery area to be kept around 10C for about 100wh/day... much less than I predicted (this is obviously a rather high temp for a normal refrigerator). If you're talking about a 10kwh pack size (about 2-2.5cubic feet) it shouldn't be any problem at all keeping it 10C even during 90F degree weather.

I'll know once I dig into it myself soon... but I'm going to attempt to make a cooled battery area.

In fact a tiny 25watt solar panel should provide the daily electricity necessary if you just use about 4-8 inches of polyurethene/fiberglass insulation (which is waaay less than I was planning to use anyway)

Well that's a good thing... I'm pleased.

Much easier to just baby them with constant temps  I need to stop being so excited about this... it's still a few months away before I can really get dirty and get my body/frame built... but man this will be fun... refrigerated batteries for the win.


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## JRP3 (Mar 7, 2008)

Cool temperatures may help shelf life but I think they actually perform better at higher temps, like 40 C or so.


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## Technologic (Jul 20, 2008)

JRP3 said:


> Cool temperatures may help shelf life but I think they actually perform better at higher temps, like 40 C or so.


Pretty much nothing about lifepo's performs better after about 25C... you can look at the temp curves... 40C harms everything... and 60C is really bad.

10-25C is the best range ... and the lower the better as far as self-discharge and annual damage.

small fridges are so cheap and have temp circuits already wired in ($70) it will be a super easy swap in even if you set it to something like 50F... which is basically ideal...

in the winter you can use a heater if you feel like it, though for NC and many other southern states it's not needed at all. But a small heating coil could heat up a fridge sized area for even less total wh/day... so it's really just preference and where someone lives (as far as marketing goes). The fridge would autoturn off at like 50F so you could just set the heater to activate at say -5C and shut off at 10C... if you wanted... temp controllers are cheap.


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## Technologic (Jul 20, 2008)

JRP3 said:


> Sounds as if it wasn't charged long enough, or maybe it needs to see higher voltage when charging, how high does it read on the charger?


Hmm I'm curious if you're right now JRP3.

http://www.skyenergy.com.cn/EnProductShow.asp?ID=6

This shows a 4.0v nominal for the TK90AHA over parts of the discharge range (actually from 100%-20% charge it averages 3.7v)... 

It's possible I undercharged this quite a bit... I was just going by what they told me from the manufacturer.

4v x 90AH = 360WH (just say useable range of 80% of that). At the $1.1/AH price that means this will actually be 0.27/WH.. (or 333WH if you count the average over the first 80% of the discharge... which would be 0.29/WH)

Maybe I should retitle the thread if that's the case 

I will have my own chart resembling that one (same method measuring) up to 0.5C discharge sometime sat/sunday... I'm off to bed... have mock court in the morning... cheers.


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## david85 (Nov 12, 2007)

Technologic, are these LiFePO4 cells? 4V/cell seems too high for that chemistry. What am I missing here?


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## Technologic (Jul 20, 2008)

david85 said:


> Technologic, are these LiFePO4 cells? 4V/cell seems too high for that chemistry. What am I missing here?


They're LiFePO4, same exact chemistry (though different cells) as the TS LS90AHA or whatever their name is.

4v seemed high to me as well after looking at the chart, I was initially told 3.2v was the nominal voltage... but I can't know until I attempt to charge it again and see if it "comes to rest" at 4+v after a few hours


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## JRP3 (Mar 7, 2008)

3.2 is nominal, just as a 12 volt battery is 12 volts nominal, but it's considered charged at 12.7 volts. How many amps are you charging with? It looks like you want about 40 amps till you are at around 4 volts or so then amps taper off for about an hour as voltage holds steady.


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## coryrc (Aug 5, 2008)

Technologic said:


> With decent insulation one can expect their battery area to be kept around 10C for about 100wh/day...


Are you counting heat generated from the battery due to internal resistance?


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## david85 (Nov 12, 2007)

I didn't know a123 lost the bid for the volt. Good to know. Not sure yet if it means anything, but still good to know.


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## JRP3 (Mar 7, 2008)

From what I've read it sounds as if LG had the more mature product and greater manufacturing capacity, as well as the fact that GM didn't want to use cylindrical cells.


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## david85 (Nov 12, 2007)

I wonder what this means for a123? Their patent was delt a blow by the european patent office last year, but to loose a customer the size of GM can't be good.


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## Technologic (Jul 20, 2008)

coryrc said:


> Are you counting heat generated from the battery due to internal resistance?


The batteries wouldn't heat up unless you were driving?

I'm just talking about protecting the batteries during summer days, while driving they might heat up, but that's actually a good thing


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## speculawyer (Feb 10, 2009)

david85 said:


> I didn't know a123 lost the bid for the volt. Good to know. Not sure yet if it means anything, but still good to know.


I suspect they just had a higher price. The A123s are well-known for their great power output . . . and their high price.


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## Technologic (Jul 20, 2008)

speculawyer said:


> I suspect they just had a higher price. The A123s are well-known for their great power output . . . and their high price.


lol and their 500 cycle life spans 

A123s are pretty much a big failure from what I can find to read about them... approaching something like .80-$1/wh even in OEM volumes, while lasting less than 1500 cycles even with extreme care taken.


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## Technologic (Jul 20, 2008)

I got my CBA II and got it installed (it was annoying to get it working)...

Look for at least 2 full battery tests (one at 0.25C and 0.5C) tomorrow in a new thread... that will start the process.

Here's a picture of the Sky Energy TK90AHA... likewise initial power tests show 3.296v nominal... I'm going to be testing discharges using the CBA II which will show voltage from 100% to 15% DOD as a function of amphour capacity


Look for a new thread once I get hard data. The battery is heavier than you'd think... though it's actually quite small

I'm still shooting for 50 cycles and mapping the differences... then potentially (possibly) attempting to "crash" the battery and see how the case holds up.

I'm going to quick charge it as well... shooting for a 2 hr charge cycle and see how it holds up... it SHOULD be capable of it...


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## Technologic (Jul 20, 2008)

k currently I'm trying to get my DC supply to stop ramping up to 50amps x 4.3v upon connection with the battery... I believe this is why my initial tests are only showing about 85% capacity it's supposed to have (because of the fast charging).

Going to discharge and either series resistor in line with the outputs, or pot box the output.

I hate messing with DC supplies... far too worried about electrocuting myself


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## david85 (Nov 12, 2007)

You're worried about electrocuting yourself with 4.3 V?


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## Technologic (Jul 20, 2008)

david85 said:


> You're worried about electrocuting yourself with 4.3 V?


lol this DC regulated supply is variable to 24v x 50amp 

not particularly worried... more worried about the battery 

I'm trying to monitor the charge cycle atm with the CBAII... something's muffed up the amp-meter on the supply is at 0 but the voltage is at 4.25v


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## ElectriCar (Jun 15, 2008)

I believe you'll need a bit more than 24V to be electrocuted. However 144V is very lethal. I'm surprised there hasn't been more reported deaths of EV'ers.


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## Technologic (Jul 20, 2008)

I'm using a straight regulated DC supply with selectable voltage output (via a back area that will change the circuit).

Here's my current CBAII charging so far... it's posting 0 amps...

That would suck if my old DC supply broke on me 
Fuse is not burnt... nothing that basic is going on.

Likewise it appears the amperage meter on the front of the rack mount is showing 0amps now... so weird.


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## david85 (Nov 12, 2007)

I was able to get a little buzz from 12-14V while working on my truck but I had touched a 12V source with a fresh scrape on my palm so the skin was thin enough for some power to ground through me. Just a tingle. Now the ignition system on the other hand....... (litterally the hand)


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## Technologic (Jul 20, 2008)

grrr I'm pissed I'm pretty sure my PSU just fried itself now. I can not pull any amperage out of it.

Luckily I just bought this... so refund time?  stupid pyle brand garbage.

On a happier note the CBA II is a monster... very pleased with it so far...


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## Technologic (Jul 20, 2008)

rmay635703 said:


> I would assume most people here have enough sense that they have never been burnt by DC both by how they design the car and because its easy to see what not to do.


DC doesn't worry me in general (I used to hand 300amp draws out of alternators with bare hands never worrying much).

What worries me is when rack mounted PSUs have their bare AC input wires exposed right next to the output terminals for the DC 

I've electrocuted myself with 110v many many times over the years (once a halogen lamp was oiled via removing a transmission... and "shock shock shock" for 10 min every time I accidentally touched the car's frame)


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## DIYguy (Sep 18, 2008)

ElectriCar said:


> I believe you'll need a bit more than 24V to be electrocuted. However 144V is very lethal. I'm surprised there hasn't been more reported deaths of EV'ers.


50 volts is the generally accepted limit for safety. It's unlikely that electrocution will result from EV systems though, as the ground path is isolated to the battery circuit..... not earth ground....


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## ElectriCar (Jun 15, 2008)

True, but all you have to do is touch two points of the system and "POW!" you're hair is smoking! I took a label maker and installed warning stickers under the bed of my truck and under the hood.


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## Camaro (Jul 29, 2008)

So I've been looking around for LifePo batteries and I found this website:

http://www.everspring.net/txt/product-battery-LFP160AHA.htm

It looks almost identical to this battery:

http://skyenergy.en.alibaba.com/pro..._power_battery_for_golf_cart_battery_car.html

The big difference is that the first website says 1000 recharge cycles while the second says 2000. Which one is right? Are they really that different in chemistry that one would last twice as long as the other? In which case the blue is so much better than the yellow!

Tech, I'm glad you got the blue ones.


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## Technologic (Jul 20, 2008)

Camaro said:


> It looks almost identical to this battery:
> 
> http://skyenergy.en.alibaba.com/pro..._power_battery_for_golf_cart_battery_car.html
> 
> ...


Those are not the same battery

The first is a thundersky version that also is both lower voltage and lighter... Sky Energy makes a "similar" battery, that's slightly cheaper. But the blue versions are their better line of LiFePO from what I was told.

The chemistry is different, because thundersky changed around a lot of their stuff to make it cheaper (though it's not cheaper than Sky Energy's btw).

Also from what I can find out (limited information) Sky Energy is subsidized by the chinese government. I don't want to give any more suspicions until I am able to at least start my testing (DC power supply can rot in hell argh).

Thundersky's prices are still close to the 0.50/wh range though...

Those might be the same cell (clearly the same battery graph) but I'm fairly certain the companies are only loosely related at this point... and that lower line TS battery isn't really the same (we'll have some idea soon I guess)


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## JRP3 (Mar 7, 2008)

Technologic said:


> Those are not the same battery
> 
> The first is a thundersky version that also is both lower voltage and lighter... Sky Energy makes a "similar" battery, that's slightly cheaper. But the blue versions are their better line of LiFePO from what I was told.


They both weigh the same, same physical dimensions, and TS says 2.5-4.2 voltage range where the SE page says "Operating Voltage 3.3-2.0V. What makes you think the TS version is lower voltage and lighter?


> Thundersky's prices are still close to the 0.50/wh range though...


Some have claimed they are getting TS cells for 0.35/wh as well.


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## Technologic (Jul 20, 2008)

JRP3 said:


> They both weigh the same, same physical dimensions, and TS says 2.5-4.2 voltage range where the SE page says "Operating Voltage 3.3-2.0V. What makes you think the TS version is lower voltage and lighter?


that is a 160AH version... check the sky energy site... their's claims 6kg 


> Some have claimed they are getting TS cells for 0.35/wh as well.


I heard about that... but nobody's heard anything about it since? 

They could be the same, no telling IMO, but TS has a lot of different "versions". Sky Energy has 2 different ones... there's at least "something" going on there.


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## JRP3 (Mar 7, 2008)

Technologic said:


> that is a 160AH version... check the sky energy site... their's claims 6kg



From the Sky Energy page for the 160Ah battery:

Specification of 160AH li-ion battery Nominal Capacity

Weight 5.6kg ±100g
http://skyenergy.en.alibaba.com/pro..._power_battery_for_golf_cart_battery_car.html


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## Technologic (Jul 20, 2008)

JRP3 said:


> From the Sky Energy page for the 160Ah battery:
> 
> Specification of 160AH li-ion battery Nominal Capacity
> 
> ...


hmph you're right

http://www.skyenergy.com.cn/EnProductShow.asp?ID=5

I just have a terrible memory then. 
There seemed to be some differences when I was looking at both sites the other day

For instance:
http://www.thunder-sky.com/pdf/20092201190.pdf
LFP90AHA claims to be 3.2kg vs Sky Energy's 3.0kg

it also appears to have the same >2000 cycles spec (vs. the other 160AHA)

http://www.skyenergy.com.cn/EnProductShow.asp?ID=6

I'm prepared to say they "are" the same cell, but construction "may" be different.

Likewise in either instance both are yielding 2000-3000 supposed cycles (not that I imagine most people would ever even get to use half that?)

I think it's pretty obvious that their graphs are the same etc... which makes sense if they're using the same cells (and were once a single company)

The graphs are scaled differently though... as far as the test data... (sky energy shows a higher voltage over the discharge)


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## Technologic (Jul 20, 2008)

Good news folks... my terminal connections to the battery were bad (causing the DC power supply to ramp up without a load).

I'm now currently recharging the battery with the CBAII charge monitor... charts to follow

Cheers.


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## Technologic (Jul 20, 2008)

Ok since I got my DC PSU to work it's causing a few issues that need constant adjusting (namely as the DC supply heats up both voltage and amperage drops... )

Here's a very very short (5 min) discharge of the battery at about 10% charge capacity... you can see just how the CBAII battery analyzer works though

I will try to be patient and get a full charge/discharge cycle done by tomorrow (at 0.5C discharge which is the max I can test)

After messing with it for this long... I will be lucky to have the patience to test 10 cycles  9+ hrs to charge and upwards of 2 hours to discharge with a chart.


Lots of energy is such a light little thing. As you can see from this chart though, voltage drop at ultra low capacity could still get you "home" potentially, but it's definitely not advisable to run these things at any serious C rating below 15% capacity or so


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## ClintK (Apr 27, 2008)

Can I recommend starting a new thread for the battery tests? We're up to 290 posts here and it may get hard to review results. 

I'd like to add a link to your tests similar to David's tests http://www.diyelectriccar.com/forum...k-techniques-lifepo4-cells-25818.html?t=25818


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## Technologic (Jul 20, 2008)

ClintK said:


> Can I recommend starting a new thread for the battery tests? We're up to 290 posts here and it may get hard to review results.
> 
> I'd like to add a link to your tests similar to David's tests http://www.diyelectriccar.com/forum...k-techniques-lifepo4-cells-25818.html?t=25818


I plan to do so once I actually get a real test for everyone... this is just me getting used to the CBA and frustrations 

Also the positive terminal screw appears to be aluminum with anodization on it  a very poor choice on their part (aluminum oxide is one of the best electrical insulators)

You definitely need a connection directly to the post... not the screw part of the battery.

All further information on the battery can be seen here;
http://www.diyelectriccar.com/forums/showthread.php/sky-energy-tk90aha-test-0-35-28708.html


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## Wirecutter (Jul 26, 2007)

Technologic said:


> Also the positive terminal screw appears to be aluminum with anodization on it  a very poor choice on their part (aluminum oxide is one of the best electrical insulators)


FWIW: Some years ago, I worked around big network switches with low voltage, high amperage DC (+5v, +12v, etc) being distributed up and down the box. The connection area of aluminum bus bars running this stuff looked like it had an oxide layer on it, but the "power supply guy" at our company assured me that it wasn't. (Another engineer once used a wire brush to "clean it off" before bolting on to it once with amazing heat-producing results.) Apparently, the stuff in this case was actually some kind of conductive coating, although I confess I don't know what it was. Ok, well it was yet another helpful thing that looked like exactly the opposite of what it actually was. 


-Mark


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## dtbaker (Jan 5, 2008)

Technologic said:


> I will be doing rigorous and mind blowingly annoying testing on this cell probably for 100 cycles before I'm prepared to order.


....and so, how did testing work out? 

Do you have a solid configuration of batteries, BMS, and importer you are happy with? At the price you thought?

I am just trying to keep tabs for my NEXT car. when it looks like I can get a package off the shelf that doesn't require custom breadboarding a BMS, and has some history on life-cycles....


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## Technologic (Jul 20, 2008)

dtbaker said:


> ....and so, how did testing work out?
> 
> Do you have a solid configuration of batteries, BMS, and importer you are happy with? At the price you thought?
> 
> I am just trying to keep tabs for my NEXT car. when it looks like I can get a package off the shelf that doesn't require custom breadboarding a BMS, and has some history on life-cycles....


Testing is working just fine for right now going to try some 1C and higher tests I hope soon.

BMS wise the goodrum/fetcher will probably be my choice... you can check out the testing thread in this forum.


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## lorraine (Feb 11, 2009)

you are right,they draw the cycles conclusion depends on the charge/discharge rate of 0.3CA.. My engineer told me about this

Lorain
Headway LiFePO4 battery,keep our sky bluer!
http://www.xhnykj.com/index_en.asp
Quote:

Can you explain the "standard charge/discharge rate of .3CA"? Is this the rate upon which the cycles are based? I.E. 2000 cycles at 70% DOD, while pulling only .3CA?? I haven't been clear on this figure.

Thanks.

Rob 
That confused me as well, but I was told 3CA was the normal discharge rate... and 10CA was the maximum.


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## dtbaker (Jan 5, 2008)

lorraine said:


> you are right,they draw the cycles conclusion depends on the charge/discharge rate of 0.3CA.. My engineer told me about this
> Lorain



so.... if 2000 life cycles are based on .3 CA, we really have no idea how they will do in real life use in an EV.


d


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## Technologic (Jul 20, 2008)

dtbaker said:


> so.... if 2000 life cycles are based on .3 CA, we really have no idea how they will do in real life use in an EV.
> 
> 
> d


That's a pretty large assumption that does not follow anything I've been told.


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## JRP3 (Mar 7, 2008)

It seems the harder you draw from the battery the shorter the lifespan, so that does seem to be a reasonable assumption. TS shows "standard" charge/discharge at .3C, so that's probably the rate they base their life cycles on.
http://www.thunder-sky.com/pdf/TS-LFP60.pdf


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## Technologic (Jul 20, 2008)

JRP3 said:


> It seems the harder you draw from the battery the shorter the lifespan, so that does seem to be a reasonable assumption. TS shows "standard" charge/discharge at .3C, so that's probably the rate they base their life cycles on.


It's possible, however, it's unclear what if any damage it will do to the cycle.


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## JRP3 (Mar 7, 2008)

Since excessive heating will shorten the cell life, higher discharge rates will presumably lead to elevated cell temps from internal heating, which could potentially lead to reduced cell life. Lower discharge rates, less stress on the cell, longer cell life.


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## Grant_NZ (May 28, 2008)

Is there any more news on the sample testing or has there been a separate thread started for this?


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## Technologic (Jul 20, 2008)

Grant_NZ said:


> Is there any more news on the sample testing or has there been a separate thread started for this?


Separate thread... in this forum


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