# hi power batteries



## motor guy (Dec 17, 2008)

hello all
just wanted to tell everyone about our situation. and/how hi power and the electric car co made everything right.
my name is kevin from topeka electric motor, we have showed you our 2000 s10 truck. topekaelectricmotor.com this is were it can be viewed.
we have 48 cells 200 amphr. with reap bms.
shortly after we had the truck running our bms found that we had some weak cells, these cells wouldnt hold the same substainable charge, we made 3 long test runs to try to get over the 100 mile mark, the batteries all performed exactly,the same to about 75miles. and then you could watch the voltage levels lowering considerably faster on these cells than the other cells. we had 10 cells showing these signs. you could put the truck on the charger and these 10 cells would come back to the correct voltage and all 48 cells would end up .030 volts from highest to lowest. like i said we did this test 3 times, loging voltages per cells and total volts per mile. aslong as you only drove less than 70 miles and then recharged, the cells performed exactly the same,you wouldnt of know there was a problem, until you went over that range and you then had these lower cell issues. without a good bms it would be hard to find and prove these issues.
hi power batteries say they have a 2 year warranty, well after all the documention and proof, we had 48 new cells show up at our shop today. we will be installing them this weekend.

big thanks to carl clark (electric car co ) and hi power batteries. stand up companies are hard to find these days.

thanks kevin


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## DavidDymaxion (Dec 1, 2008)

Great story! I have bought several things from Carl and have been happy. Here's his web site: 

http://www.evequipmentsupply.com

BTW motor guy whats the max Amps you could pull from those CHP 200 Ahr batteries, and for how long? I bought a couple that I'm going to torture test after I'm done torture testing the 10 Ahr cylindrical cells.


motor guy said:


> hello all
> just wanted to tell everyone about our situation. and/how hi power and the electric car co made everything right.
> my name is kevin from topeka electric motor, we have showed you our 2000 s10 truck. topekaelectricmotor.com this is were it can be viewed.
> we have 48 cells 200 amphr. with reap bms.
> ...


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## motor guy (Dec 17, 2008)

thanks david

carl has told me about your car, sounds real neat. also tell him you want a copy of the video of our truck he made up.
let me know how the torture test works out.

maybe i am just over stimulated, about our new ac motor but i think there are going to be some big gains made in the ev world in the next few months from all who develope the new ideas.

thanks kevin


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## DIYguy (Sep 18, 2008)

motor guy said:


> hello all
> just wanted to tell everyone about our situation. and/how hi power and the electric car co made everything right.
> my name is kevin from topeka electric motor, we have showed you our 2000 s10 truck. topekaelectricmotor.com this is were it can be viewed.
> we have 48 cells 200 amphr. with reap bms.
> ...


Hi Kevin,
48 cells of 200 Ah is 30720whr. To cover 100 miles you would have to run with an efficiency of 307 wh/mile. That's a lofty goal for an S10 truck. Did you check any of the 10 weaker cells to see how many Ah they were capable of discharging? Most people with this kind of vehicle would be happy with 400 wh/mile...which would give you about 76 miles. Perhaps the weak cells aren't too far off the actual 200 Ah rating??? 

Cheers,


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## motor guy (Dec 17, 2008)

we have alost gone 100 miles, like we have stated 95.5 miles is our best to date. no cigar yet.
the good effiency, i think is all beause we use the 5 speed transmission to stay in the warp 9's best power range, you will soon figure out the amps per mph to achieve the best range.
one item i find very interesting is that on slave #2, cell's 9,10,12 will drop their voltage around the 85 mile range to about 2.5 vdc,while cell #11 is still above 3.0 vdc. when this happened the first time we took a vom meter and check all the battery voltage to make sure the bms wasnt giving us bogus readings. our batteries are all series connected.
we had to answer alot of questions and send lots of data to prove there was an issue to hi power, i am so glad we bought a good battery management system that can supply you with that kinda data.
that was a good lesson learned.

thanks kevin


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## DIYguy (Sep 18, 2008)

I'm just thinking that perhaps your weaker cells still have 200 Ah and the rest have more? Can you test one of them? (for what you paid for that BMS...you could have bought another small pack of batteries! lol)


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## JRP3 (Mar 7, 2008)

Let me also point out an easy way to know your cell capacity is to bottom balance your pack. Once you have them all discharged to the same SOC you monitor them when charging. When the voltage starts to shoot up on the first one, (around 3.50 for SE/CALB), you know it's reaching full and you know it's your smallest capacity cell. Using an amp hour meter you know how many amp hours went into it. Also, my SE/CALB cells all came with a data sheet listing actual capacity and resistance for each cell, tested at the factory. I guess HiPower doesn't do the same? You can also use a $30 Cell Log 8 to log 8 cells at a time to see how they behave under load.


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## david85 (Nov 12, 2007)

Good to know that Hipower honored their warranty. 100 miles out of a battery that size in that type of vehicle is impressive.


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## DIYguy (Sep 18, 2008)

Very true David.... impressive indeed. It's ironic when u think about it.... "we" are all worried about the Chinese battery manufacturers and dealers screwing us ... and the only ones I've seen screwed are from here! lol.

I can't see them (Chinese battery guys) screwing folks and expecting to do more business. Can you??? If I recall David, you stuck your neck out and ordered batteries from a vendor that was little known and had them shipped direct.... yes?


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## david85 (Nov 12, 2007)

Correct, although I carried out testing on a 12.8V sample first to try and verify the reserve capacity and High current draw (although I was only able to do a rough test of 3C @ 10 seconds). So far the battery has performed well, but with only about 2000 kilometers on all electric, it doesn't say much.

The company that sold my batteries was an interesting one because they carried every kind you could imagine. LiFePO4 was the most obvious but they also had NiCad, NiMH, and NiFE among a long list of others among in and lithium varieties.

What gives me some reason to celebrate is that Kevin's battery is a carbon copy of mine in terms of rated capacity AND system voltage.


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## DIYguy (Sep 18, 2008)

david85 said:


> Correct, although I carried out testing on a 12.8V sample first to try and verify the reserve capacity and High current draw (although I was only able to do a rough test of 3C @ 10 seconds). So far the battery has performed well, but with only about 2000 kilometers on all electric, it doesn't say much.
> 
> The company that sold my batteries was an interesting one because they carried every kind you could imagine. LiFePO4 was the most obvious but they also had NiCad, NiMH, and NiFE among a long list of others among in and lithium varieties.
> 
> What gives me some reason to celebrate is that Kevin's battery is a carbon copy of mine in terms of rated capacity AND system voltage.


If I may inquire....what was it that convinced you to send your $$ in advance of having product? Was there any particular thing?.... No other buyers to praise them? or... a revelation moment of some kind


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## david85 (Nov 12, 2007)

What I did wasn't completely without precedent at the time. Back then I had already looked at conversions using thundersky LiFePO4 cells that had a few years on them and I took the time to contact some directly to ask how they were performing. No one that I found had anything bad to say about them.

TS is of course a different company, but the chemistry is the same and after I received a sample that worked as they claimed, I felt "less uncomfortable" about buying something like this. They also answered all my questions and when I plotted my measured discharge curve to compare it to their plot it was a perfect match. I sensed there was also a realization on behalf of many chinese companies that they had to overcome much of the bad wrap that TS placed on all of them a few years ago when a large group buy of lithium batteries turned sour and they didn't perform as advertised. This was before TS introduced the current gold standard LiFePO4 series.

The chinese are slowly starting to embrace western 3rd party payment methods like credit cards and paypal or equivalent so a direct wire transfer is becoming obsolete (thankfully). Are they better than thundersky or sky energy? I have no idea. There simply aren't enough miles on my car to say for sure.


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## motor guy (Dec 17, 2008)

hello all, just wanted to say our new batteries are installed and must say we are very happy.


thanks 
kevin 
topeka elctric motor


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## strawberry (Feb 22, 2010)

DIYguy said:


> If I may inquire....what was it that convinced you to send your $$ in advance of having product? Was there any particular thing?.... No other buyers to praise them? or... a revelation moment of some kind


I have a friend who installed Hipower 300V100Ah battery pack, he had put 496 miles on the pack for one charging.


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## hipowerkevin (Jan 14, 2010)

One of my customer in Germany, he convert Porsche, here is her car data:

Porsche 912
2 + 2 seater
electric motor: 72KW / 350Nm
Gearbox: 5 speed
battery: HIPOWER 40S2P / 128V / 200AH / 25,6KWH
weight: 1150Kg inclusive batteries
max. speed: 165KPH with two passengers
cruising speed: 120KPH
range: 200+ Km at 100KPH with two passengers

Here is his car


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## DIYguy (Sep 18, 2008)

hipowerkevin said:


> One of my customer in Germany, he convert Porsche, here is her car data:
> 
> Porsche 912
> 2 + 2 seater
> ...


Those numbers are a little more realistic... not many cars could get 125 wh/kilometer (205 wh/mile) at 100 kph.... ??? Nice looking ride though!


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## DIYguy (Sep 18, 2008)

strawberry said:


> I have a friend who installed Hipower 300V100Ah battery pack, he had put 496 miles on the pack for one charging.


your "friend" is leading you down the garden path... this is not technically possible. This is your second post here.... are you spamming?

edit.....I see that you are a rep for Hi Power batteries. You may not realize it, but you have just done some damage to your companies' reputation....


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## strawberry (Feb 22, 2010)

DIYguy said:


> your "friend" is leading you down the garden path... this is not technically possible. This is your second post here.... are you spamming?
> 
> edit.....I see that you are a rep for Hi Power batteries. You may not realize it, but you have just done some damage to your companies' reputation....


yes, I am a rep, from Hipower, my name is Candy, my friend from USA, who has 25 years experience for batteries. in 2008, he bought 300V100Ah battery pack, but because our equlizer charger damage most of the cells, then this year we make replacement for the whole pack, now he is very happy for the Hipower upgrading cells . you can check the original Email from him as attached. I just want to verify not only one customer speaks highly about Hipower cells. nothing special .


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## todayican (Jul 31, 2008)

Looks like a lost in translation thing..

Candy, if you were explaining the differences between the Calb, Thundersky, and Hi-power 100ah cells, what would they be? Why would one buy one above the other?
Thanks
Tom


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## major (Apr 4, 2008)

strawberry said:


> yes, I am a rep, from Hipower, my name is Candy, my friend from USA, who has 25 years experience for batteries. in 2008, he bought 300V100Ah battery pack, but because our equlizer charger damage most of the cells, then this year we make replacement for the whole pack, now he is very happy for the Hipower upgrading cells . you can check the original Email from him as attached. I just want to verify not only one customer speaks highly about Hipower cells. nothing special .
> 
> View attachment 8573


Hi Strawberry Candy,

I think you read this incorrectly. 



strawberry said:


> I have a friend who installed Hipower 300V100Ah battery pack, he had put 496 miles on the pack for one charging.


Or wrote this incorrectly. 

I read that attached email as saying he has gone 496 miles on multiple charges of 40 to 50 miles per daily charge. NOT 496 miles on a single charge.

Might be a language thing going on here 

Regards,

major


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## JRP3 (Mar 7, 2008)

strawberry said:


> I have a friend who installed Hipower 300V100Ah battery pack, he had put 496 miles on the pack for one charging.


Just to be clear, the 496 miles were not done on one charge, but many charges between 40 and 50 miles each.

*Ah Major beat me to it.


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## strawberry (Feb 22, 2010)

todayican said:


> Looks like a lost in translation thing..
> 
> Candy, if you were explaining the differences between the Calb, Thundersky, and Hi-power 100ah cells, what would they be? Why would one buy one above the other?
> Thanks
> Tom


 Tom, thank you for your question, a good question. 
And I just can tell you that the single cell are nearly same, but for the battery pack, we can provide all in one solution. 
As a Hipower Rep here, I don't make a sale as a purpose here, just make my customers happy, Kevin Constant is my customer, Carl Clark, I have many customer is happy with Hipower cells, just because Hipower has done a lot which can make them happy , thanks for all , we can enjoy the high-quality LiFePo4 battery. 
Candy


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## todayican (Jul 31, 2008)

Where might I find specs for the 100ah cells?
Thanks


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## strawberry (Feb 22, 2010)

todayican said:


> Where might I find specs for the 100ah cells?
> Thanks


 if you feel convenient, you can send the request for 100Ah Spec by Email , my Email adress is [email protected] . 
if you want to buy cells, you can buy from Carl Clark, 001-8012435300
-- Keep Smiling & Never Give Up !!!​
TKS & Best Regards​
Candy Yan ​
008613874997703​


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## DIYguy (Sep 18, 2008)

Yup, all good. Thanks guys. Sorry Candy...was just the wording there. 

Cheers.


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## JRP3 (Mar 7, 2008)

strawberry said:


> if you feel convenient, you can send the request for 100Ah Spec by Email , my Email adress is [email protected] .
> if you want to buy cells, you can buy from Carl Clark, 001-8012435300
> -- Keep Smiling & Never Give Up !!!
> 
> ...


If you just post the specs here on the board then everyone can see them.


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## strawberry (Feb 22, 2010)

JRP3 said:


> If you just post the specs here on the board then everyone can see them.


Thank you so much for your suggestion, here is it . 
View attachment HP-PW-100AH Specification.pdf

-- 
Keep Smiling & Never Give Up !!!

TKS & Best Regards

Candy Yan 

008613874997703​


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## JRP3 (Mar 7, 2008)

Thank you. Is each cell tested for actual capacity and internal resistance, do they come with a data sheet with that information, and how close to each other are the cells in capacity? For example, my SE/CALB cells each had a serial number and a data sheet referencing tested capacity and resistance. The 100ah cells all were between 110-114 actual capacity. Closer grouping of capacity would be preferred and make management easier.


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## motor guy (Dec 17, 2008)

hello to all

i would like to offer more input if anyone is looking to purchase a set of hi power batteries, or are just have some questions on how they act or perform under load.

i will try to answer any question to the best of our ability, if we dont know i would be glad to try to find out.

since we have installed our new pack, our weather has been colder, in the 20's in the morning and highs about 45, we have been driving and useing our heater and charging in the afternoon,and all seems to be good. they are charging up balanced and have very good power even when cold.

we are not trying to stand up for any companies past behavior or actions, all i know is what they have done now. they seem to be attempting to make all better. but i will give a piece of advise to hi power " if you trip and fall again,and dont support your customers, your reputation will be completely damaged beyond repair." that will most likely mean no more sales of batteries to the usa ev market.

our ph # is 1-785-233-4750

thanks kevin constant
topeka electric motor inc.


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## motor guy (Dec 17, 2008)

hello to all

on our new pack we got a test sheet and a serial # sheet. the test sheet showed that the pack had 213 amphr per cell.

thanks kevin constant
topeka electric motor inc.


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## JRP3 (Mar 7, 2008)

motor guy said:


> hello to all
> 
> on our new pack we got a test sheet and a serial # sheet. the test sheet showed that the pack had 213 amphr per cell.
> 
> ...


Each cells was exactly 213 ah? Do they all discharge and charge to the same value? Have you pulled the whole pack down below 3.0 volts per cell?


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## motor guy (Dec 17, 2008)

hello

no we have taken them that low yet. i was waiting to get a few cycles on them first. but as soon as i do i will tell the world the findings.
because i believe that the truth will make better products.

thanks kevin


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## Guest (Nov 30, 2010)

Were there any 100 AH Hi-Power batteries sold that were just crap batteries? How many folks here are using Hi-Power 100 AH batteries? How are the holding up? Performing? 

PDF says greater than or equal to 1000 cycles. I thought the cells were in the range of 2000 to 3000 cycles, not 1000? Must be confused on this one. 

Anyway, Would Hi-Power be a good alternative to TS or CALB in performance and price for the 100 AH size batteries? 

Pete


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## todayican (Jul 31, 2008)

got the pricing and thats attractive anyways...


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## hipowerkevin (Jan 14, 2010)

JRP3 said:


> Each cells was exactly 213 ah? Do they all discharge and charge to the same value? Have you pulled the whole pack down below 3.0 volts per cell?


Dear JRP3,

This is Kevin from Hipower, very glad to meet you. I would give some suggestion about your question. Batteries would made some extra AH, for high C-rate discharge.. Our engineers would make about 5% to extend 3C continuous discharge, they think it is enough.

Hipower battery is somehow different than Thundersky or CLAB, We use "Aqueous solution" technology, it is more suitable for electron translation in Aqueous liquid, the charge and discharge ability is better than "oily solution", and it is more safe. The "Aqueous solution" is translated as Chinese mean, I don't know the real English word is. However, this improved technology really have better discharge curve, and it is easier to control cell's quality as electrical property of cells in producing, cell would have more "same" property as IR, charge / discharge characteristic.

For battery packs, Hipower select the most same cells to assemble battery pack. We use CLMT (cycling,logging, matching,testing) quality control method. Use machine to pick up cells which have most same IR, as candidate, then do charge / discharge cycles, find out the most same charge / discharge curves, them pick up those cells, to make up battery pack. Our acceptable quality level is : With standard discharge to 80%DOD, the difference of cell's voltage in pack should less than 0.1V. charge to 80%SOC, the difference of cell's voltage in pack should less in 0.1V also.

If you take Hipower batteries, we could offer technical detail support, like fast charging restrict, temperature upping with different C-rate, best discharging condition consider the cycle life. We think no one know our battery than our-selfs, we need to be honest, tell customer what can do or what can not do. Customer is not a battery professor but sales need to be. So the relation is health.

Some useful information: 
*For all Li-batteries, the best using condition is not totally charged or totally discharged, it due to Li-battery chemistry.* So, in 100%DOD can cycle 1000 times, while in 80%DOD can use 2000 times. charge to 3.65V is better than 3.85V to extend the life cycles. 

All li-batteries, there is liquid in cell, if temperature is too cold, the electron in liquid would not be easily transported. The capacity would be "frozen", some of capacity can not be fully discharged. when temperature returns to normal, the rest capacity (energy) can be discharged. So design a battery box with heat insulating marital to stop cold temperature effect the battery in winter is better. You may also design some of heating wires to warm cells. For Hipower batteries, when discharging, the temperature would rise about 5 Celsius degree with 0.5C continuous discharge, 10 Celsius degree with 1C continuous discharge. 

For fast charging, All Li-battery charging method is CC/CV, and they need balancing time. Hipower battery can take 1C current charing is CC mode, which is 0%~90% SOC, 1C continuous is no effect to cycle life. While for CV mode, which is balancing time, need about 1~2 hours.

I hope it would be helpful.


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## Duncan (Dec 8, 2008)

Hi todayican

_*got the pricing and thats attractive anyways...*_ 

Don't keep us in suspense!


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## todayican (Jul 31, 2008)

She asked me to keep it off the forum and I may buy so ill honor that, just to say that its a *bit* less then TS or CALB for what, according to the specs seems like somewhat lower ratings.

She is friendly and fast with a response, hit her up


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## strawberry (Feb 22, 2010)

todayican said:


> She asked me to keep it off the forum and I may buy so ill honor that, just to say that its a *bit* less then TS or CALB for what, according to the specs seems like somewhat lower ratings.
> 
> She is friendly and fast with a response, hit her up


 Thank you so much for your frank comments, I like the style. I also do the business in this way, which we can do, then we will tell the customer the truth, we will obey the truth, not like some datasheet, bull shit on the datasheet. as the LiFePo4's physical property, 80% DOD is 2000 lifecycle, and 1000 lifecycle as 100% DOD. 
I just can say , High quality is not shown on the paperwork, and it is tested by the enduser. 
Thank you !
Candy


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## JRP3 (Mar 7, 2008)

hipowerkevin said:


> Dear JRP3,
> 
> Hipower battery is somehow different than Thundersky or CLAB, We use "Aqueous solution" technology, it is more suitable for electron translation in Aqueous liquid, the charge and discharge ability is better than "oily solution", and it is more safe. The "Aqueous solution" is translated as Chinese mean, I don't know the real English word is. However, this improved technology really have better discharge curve, and it is easier to control cell's quality as electrical property of cells in producing, cell would have more "same" property as IR, charge / discharge characteristic.


I think what you are saying is that your electrolyte is water based as opposed to petroleum, or oil based.


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## JRP3 (Mar 7, 2008)

todayican said:


> She asked me to keep it off the forum and I may buy so ill honor that, just to say that its a *bit* less then TS or CALB for what, according to the specs seems like somewhat lower ratings.
> 
> She is friendly and fast with a response, hit her up


I don't understand why certain sellers like to keep their price a secret. Other places publish their prices and shipping details so buyers can compare.


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## MN Driver (Sep 29, 2009)

JRP3 said:


> I don't understand why certain sellers like to keep their price a secret. Other places publish their prices and shipping details so buyers can compare.


It's normal in China, and many other countries, for business to be done by negotiation or through a certain price on volume. If someone gets a better deal, they don't want the customer that didn't get the better deal to know about it. I think it all comes together the same way for high volume transactions as well because the little guy buying 50 cells at 60Ah won't get far trying to buy at the same price as 100,000 cells at 200Ah, for example.

India is similar to this as well. I used to work in Minneapolis(work in the suburbs now, where parking is free) and would visit a store that sold electronics nearby from time to time and it wasn't uncommon for a man from India who is working in the US to come up and be excited while he tries to haggle a deal on 5 digital cameras to send home to his family at a big store that has fixed prices. In India, China, and many other countries, they are not direct with purchases and do not have fixed prices because they sell things market-style where deals are made.

Hope that helps make sense of it a little bit.


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## motor guy (Dec 17, 2008)

hello to all
i said yesterday that i would tell how our pack is doing.

we are testing our new pack in the cold weather here in kansas, it was 17 deg F this morning. i realize for optimum performance we should have a heated battery box. our truck is still running great with out it. the battery voltage is staying from highest to lowest .04 between all 48 cells. we have 42 miles on this charge,while running the heater, and our high cell is 3.279 and the low cell is 3.234 vdc. the sos meter shows that we still have about 50% left in the pack.

we will continue to run the pack to about 80% DOD and then tell you all the #'s.

like i said yesterday, we have nothing to hide, it is what it is, we wont bump any # to make it look better.


thanks kevin


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## strawberry (Feb 22, 2010)

JRP3 said:


> I don't understand why certain sellers like to keep their price a secret. Other places publish their prices and shipping details so buyers can compare.


Hello, everyone :
As I said here before, Hipower Rep come here, it is not for sales purpose, just for the technical and experience idea exchange, so anyone want to buy and know more about Hipower cells, you can ask me, ( Candy , I am a senior sales from Hipower, my email adress is [email protected] ), also you can contact our local distributor Mr. Carl Calrk, 001-801-2435300, he can get all the shipment together, and the customer can save a lot local charges at the port. 
Thank you 
Candy


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## dexion (Aug 22, 2009)

hipowerkevin said:


> Dear JRP3,
> 
> This is Kevin from Hipower, very glad to meet you. I would give some suggestion about your question. Batteries would made some extra AH, for high C-rate discharge.. Our engineers would make about 5% to extend 3C continuous discharge, they think it is enough.
> 
> ...


 
Kevin,

you mention too cold and back to normal for temperature changes. But you didnt mention what too cold or normal is. Can you clarify with actual ranges of temps? Also would the cycle life of a cycle be reduced if it was say always stored at 80F as opposed to 70F or even 100F etc? And also what about charging below freezing too.

thanks


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## motor guy (Dec 17, 2008)

hello all

well i just wanted to up date our mileage and voltage. for the new pack.
we have run our pack down to 20.5% on the sos meter,after 59.5 miles. 20.2 of which were on the hiway, 60-65 mph.it has been cold here so we are also running our heater. we started with our total pack voltage of 163.2 vdc. 

after pulling in the drive way tonite and not giving the cells any time to rest or regain any voltage by sitting, the highest cell was 3.144. lowest cell was 2.933. for a total pack voltage of 147.636. for 48 cells.

we put the batteries on the charger tonite,it is the 5th time on the charger,and we will see in the morning how it is, the weather guy says single digits tonite for the temp. so some cold test runs in the morning.

thanks kevin


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## hipowerkevin (Jan 14, 2010)

dexion said:


> Kevin,
> 
> you mention too cold and back to normal for temperature changes. But you didnt mention what too cold or normal is. Can you clarify with actual ranges of temps? Also would the cycle life of a cycle be reduced if it was say always stored at 80F as opposed to 70F or even 100F etc? And also what about charging below freezing too.
> 
> thanks


Hello Dexion,

Hipower LiFePO4 battery can discharge in -20°C to 60°C, it would not effect cycle life. 
The best using condition is 15°C to 45°C, have best available capacity. 
Low temperature would effect capacity,not effect cycle life. But we should avoid liquid be frozen, it would effect the inner structure little. We estimate liquid be frozen about -35°C. While we suggest working condition above about -20°C.

For high temperature, LiFePO4 battery is very suitable for high temperature condition compared with other Li-battery, other Li-battery would get dangous condition or cycle life loss. For LiFePO4 battery, all professor think working condition lower than 75°C is safe. While we take 60°C, as recommend for using. just take it. 

For charge, 0~45°C

For storage, -20~45°C is no problem, would not effect cycle life, you know storage means electron would not move, battery inner, any thing would be no move, -20~45°C is OK for storage.


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## dexion (Aug 22, 2009)

Thank you. I have taken to just keeping them at 25C (80F) all year round (im in detroit) via heating pads under the batteries. I just wanted make sure I wasnt lowering their life that way.


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## DIYguy (Sep 18, 2008)

Hey Dex, how are those Blackhawk Li batts working out for you? .... and do u use the heating wires on 110 VAC only?

Cheers,


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## dexion (Aug 22, 2009)

They are working fine I cant really see any difference from day 1. I really dont take them down far. Most I go is down to 40% soc but thats rare (perhaps 4 or 5 times.) Notmally its down to 60% soc. But, I cant really complain so far. I have about 15000 miles on the pack. The heaters are 220V (as is the charger.) On 110 there is no heat but I do have a 110 charger if needed (never use it.) I just leave it plugged in all the time and the thermostat turns it on and off as needed my situation (having 220 at work to use) is pretty nice and takes a lot of the problems out of commuting in an electric car in the winter. 
They take a while to cool/heat (based on the one thermometer probe I have stuffed in the pack somewhere.) So the 1 hour commute isnt a problem. I just plug in at work, unplug when I leave in the winter. I can unplug it for 4 hours in 30F weather and its still 70F or so at the probe.


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## DavidDymaxion (Dec 1, 2008)

HiPowerKevin or Strawberry:

Can you tell me the dimensions, weight, and internal resistance for your 10 Ahr and 14 Ahr cylindrical cells? Thanks. My understanding is the 14 Ahr cells are new, are those being sold now? Any further info or spec sheets would be great. Many thanks for the information.

BTW I bought some 10 Ahr cells from Carl http://www.evequipmentsupply.com and have been testing them -- they seem to be doing well at 10C rates.


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## strawberry (Feb 22, 2010)

DavidDymaxion said:


> HiPowerKevin or Strawberry:
> 
> Can you tell me the dimensions, weight, and internal resistance for your 10 Ahr and 14 Ahr cylindrical cells? Thanks. My understanding is the 14 Ahr cells are new, are those being sold now? Any further info or spec sheets would be great. Many thanks for the information.
> 
> BTW I bought some 10 Ahr cells from Carl http://www.evequipmentsupply.com and have been testing them -- they seem to be doing well at 10C rates.


 Hi, can you send the request to my email box : [email protected] 
yes, our 14Ah is new. 
Thank you 
Candy


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## ElectriCar (Jun 15, 2008)

Subscribing. I like this battery and the reputation they are building along with Carl.


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## motor guy (Dec 17, 2008)

hello all

just wanted to say that all is good on the new pack. for the about the last 3 weeks it has been in the teens and 20's in the morning and about 32 deg f at the end of the day. the pack seems to work good even when it is 10 deg f. there is some loss but way less than lead acid.

we just ordered another 48 pack from carl for the new truck. we have the electrical specs on the new motor and hopfully monday we will have the mechanical demensions. it will be 72 volt, at 94.1 % eff. and A good chance we will have the first built unit by the end of janurary.

as soon as we get all the demensions and specs we will post them.

as far as the hi power batteries we are very pleased, like we said we just ordered another set. we had issuses with the first pack and hi power stood behind them and made it right.

i like very much dealing with a company that takes care of its customers. that how we run our business everyday. 

thanks 
kevin
topeka electric motor inc
ev designs dept


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## ElectriCar (Jun 15, 2008)

All you guys are out west or mid west. Hell we drive ev's on the east coast too, I need suppliers out here!


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## strawberry (Feb 22, 2010)

JRP3 said:


> If you just post the specs here on the board then everyone can see them.


 Hi, Hipower has been upgraded our SPEC, here it is . 
Thank you 
Candy 
View attachment HP-PW-100AH.pdf


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## ElectriCar (Jun 15, 2008)

Hi Strawberry! When did these go in to production? I'm looking at the 200Ah batteries now, measuring to see if I can 50 in my truck!


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## strawberry (Feb 22, 2010)

ElectriCar said:


> Hi Strawberry! When did these go in to production? I'm looking at the 200Ah batteries now, measuring to see if I can 50 in my truck!


HI, JR3 :
it is on the production already , and they can be avaliable in January . 
200AH SPEC as the attachemnt. 
View attachment HP-CT-200AH.pdf

Thank you 
Candy


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## ElectriCar (Jun 15, 2008)

If I ordered tomorrow could they ship before the holidays or do I have to wait for your 10 days off?


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## strawberry (Feb 22, 2010)

ElectriCar said:


> If I ordered tomorrow could they ship before the holidays or do I have to wait for your 10 days off?


Dear Sir :
What kind battery pack are you looking for ?
do you know what is Hipower's advantages ? and do you know why Kevin Constant's battery pack can work so great ?
We are different from other suppliers, because we well select and match the battey pack , which will take us one week time. 
that means in the same battery pack, there is closer inner resistance, capacity, volt tolerance, etc. 
thank you 
Candy


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## ElectriCar (Jun 15, 2008)

Hi Candy, I've been emailing you about this.  I want 50 pieces 200Ah cells. If I order tomorrow, Tuesday through Carl Clark, can you get them shipped before the holidays?


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## strawberry (Feb 22, 2010)

ElectriCar said:


> Hi Candy, I've been emailing you about this. I want 50 pieces 200Ah cells. If I order tomorrow, Tuesday through Carl Clark, can you get them shipped before the holidays?


 You mean to say the Chinese Spring Festival ?
is it by sea or by air ?
Thank you 
Candy


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## ElectriCar (Jun 15, 2008)

dexion said:


> Thank you. I have taken to just keeping them at 25C (80F) all year round (im in detroit) via heating pads under the batteries. I just wanted make sure I wasnt lowering their life that way.


Hi dexion, I'm very interested in your heating pads. Could you give us some details ie brand and part number of them? Also how are you controlling them? Can you post photos too? I've been thinking of what to use for this too as I know these things won't heat up like lead batteries do so I'll need to keep a little heat on them. Sure would be a big help if you'd share your knowledge!


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## dexion (Aug 22, 2009)

Unfortunately they came with the car (solectria force) but people have used waterbed heaters and soil heaters. There is a controller in the battery boxes to control the heaters. They seem to max at 90F.


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## rfhendrix (Jan 24, 2011)

Subscribing. I am looking more and more into Hi power batteries. I hope you all will keep us updated. I have already dealt with Carl (in Midvale, Utah) for other EV parts and I am very happy with his service and attitude in general.


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## Guest (Mar 18, 2011)

If you can afford to buy the new Winston Batteries with Yttrium you'd be much better off than with Hi-Power Cells. I got my Hi-Power because I got a good deal. I still like mine because of the price I paid, not because of the quality. They are good but are 08 batteries and not as good as others like TS or Calb. So I will continue to use mine until I can get the new Winston batteries. 

Pete


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## rfhendrix (Jan 24, 2011)

gottdi said:


> If you can afford to buy the new Winston Batteries with Yttrium you'd be much better off than with Hi-Power Cells. I got my Hi-Power because I got a good deal. I still like mine because of the price I paid, not because of the quality. They are good but are 08 batteries and not as good as others like TS or Calb. So I will continue to use mine until I can get the new Winston batteries.
> 
> Pete


The price is a big factor for me but I am still a few months down the road before I make a decision. Thanks for your advice.


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## david85 (Nov 12, 2007)

gottdi said:


> If you can afford to buy the new Winston Batteries with Yttrium you'd be much better off than with Hi-Power Cells. I got my Hi-Power because I got a good deal. I still like mine because of the price I paid, not because of the quality. They are good but are 08 batteries and not as good as others like TS or Calb. So I will continue to use mine until I can get the new Winston batteries.
> 
> Pete


Uh, Pete? What the heck is Yttrium? 

Proof that I've been out of the loop lately.


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## acrdesigner (Mar 16, 2011)

motor guy said:


> hello all
> just wanted to tell everyone about our situation. and/how hi power and the electric car co made everything right.
> my name is kevin from topeka electric motor, we have showed you our 2000 s10 truck. topekaelectricmotor.com this is were it can be viewed.
> we have 48 cells 200 amphr. with reap bms.
> ...


Motor guy if you dont me asking . what is the approximately weight on your truck ?
thanks


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## Guest (Mar 18, 2011)

Yttrium is a reactive metal that was used in the TS battery chemistry to basically contaminate the matrix but what that does is hold the matrix together better so it does not collapse over time near as fast. So what it is there for is structural integrity and increased the cycle life by a considerable amount with out really affecting the performance of the battery. Very little is used but that is all that is needed. Kind of like mixing carbon into iron to make steel. A little goes a long way. So now 70% DOD is up to 5000 cycles. Not quite doubled. Old style at 70% DOD was set at 3000 cycles. 

Pete


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## david85 (Nov 12, 2007)

gottdi said:


> Yttrium is a reactive metal that was used in the TS battery chemistry to basically contaminate the matrix but what that does is hold the matrix together better so it does not collapse over time near as fast. So what it is there for is structural integrity and increased the cycle life by a considerable amount with out really affecting the performance of the battery. Very little is used but that is all that is needed. Kind of like mixing carbon into iron to make steel. A little goes a long way. So now 70% DOD is up to 5000 cycles. Not quite doubled. Old style at 70% DOD was set at 3000 cycles.
> 
> Pete


Thanks Pete.

Sounds promising.


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## Guest (Mar 18, 2011)

Yes they are. Rickard is using them and he is getting them for his Escalade project too. I'd love to get them. Found out that TS was before Calb and that Calb is licensed to use the TS technology. So TS gets paid by CALB but only Winston (TS) uses Yttrium in the cells to increase the life of the cells. Price is no different than before. The older ones are still great. But the Y ones are much better. So my pick is the the Winston Batteries. They hold the patent on these cells. Others pay to use the technology. So Winston is the top of the line when it comes to these LiYFePo4 cells. Not exactly sure where the Y is to be put with the designation. 

Pete


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## david85 (Nov 12, 2007)

Did some looking on Alibaba, and ran the numbers on one example. I came up with roughly 150wh/kg on one of them but I don't know if that can be trusted. Do you know if the energy density is any different? Last I heard the "Blue" sky energy LiFePO4 version was top of the food chain with 115 wh/kg with cells like mine being around 90.


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## EVfun (Mar 14, 2010)

gottdi said:


> So my pick is the the Winston Batteries. They hold the patent on these cells. Others pay to use the technology. So Winston is the top of the line when it comes to these LiYFePo4 cells. Not exactly sure where the Y is to be put with the designation.


I have an early set of the Thunder Sky Yttrium cells. The data sheet lists them as being Thunder Sky LiFeYPO4 cells with the part number designated as TS-LFP60AHA. These are the ones I was slapping around to 5C in the Datsun that are now going in the Buggy. Right now I cannot get the Winston site to load the MSDS sheets but at one point remember seeing that there was actually more Yttrium than Iron. 

I have noticed that CALB has upped the stored capacity. The current cell they offer, in the same size as the TS 60 amp hour cell, is now rated at 70 amp hours.


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## JRP3 (Mar 7, 2008)

The other factor to consider is cell matching. So far from what I've seen CALB has the edge on that. I actually consider close grouping more important than the difference between 3000 and 5000 cycles, since 3000 cycles on a 50 mile pack is already 150,000 miles, and an imbalanced pack can kill cells quickly.


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## Guest (Mar 18, 2011)

CALB is the Density Champion but they still are sitting at 3000 cycles at 70% DOD. As for quality control? I'd almost bet one would be hard pressed to truly find any major discrepancy between the two companies. One may be a bit tighter on that control but the differences for our uses are not what I would call critical. Were talking thousandths of a volt differences and may be a few AHs differences. So you have a cell that is rated at 200 AH and it tests out to 220 AH. Wow, you got 20 free AH or a 20 AH fudge range to play with. I'd go with the Winston batteries. The differences in capacity and voltage from the factory are so small I think its a non issue. Remember that these guys are not building these batteries for us. They are building them for customers that need thousands upon thousands of them for vehicle projects. Big companies. They just don't mind selling to you. Money is money after all.


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## Guest (Mar 18, 2011)

> I actually consider close grouping more important than the difference between 3000 and 5000 cycles


The groupings are close. Work within the parameters you have and that extra 2000 cycles for the same price is a pretty big friggin deal. These batteries are already a pretty big friggin deal to begin with. Even the worst of these LiFePo4 batteries out surpass the best of any other battery made that you can buy today.


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## JRP3 (Mar 7, 2008)

I'll disagree. Closer capacity makes management much easier. Matching your cells closely makes life easier and less likely to damage an individual cell. I'm not talking about getting extra capacity, I'm talking about getting each cell capacity to closely match all the others. I'd much rather have all my cells at 210ah instead of a range from 210-220 since the extra capacity of those over 210 can't be used.


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## Guest (Mar 18, 2011)

It would be true but you purchased a cell with 200 AH and that is your basis of your setting up your cells. Not the extra that is built in. I would bet that most of the cells from Winston or CALB are close in voltage and capacity. To the point that it is truly is not something you have to worry so damn much about. I see so many making such a doo about what has been shown to work reliably for quite some time. The problem I see is that every one is trying to squeeze every ounce out of every cell every cycle. It is just such a waste of time and effort. You could actually be out enjoying your drive instead of fretting so about such small differences if you set your pack up properly. 

It is a much too do about nothing. It's like trying to scrape out every ounce of unneeded weight from your car to get that extra thousandths of a second off a blast from one green light to the next on your street car. What a waste of time. 

I agree it would be good to have the capacity close. They are.

Its fine to disagree. 

I just don't plan on wasting the time or fretting so.


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## Guest (Mar 18, 2011)

Actually that extra is being used. With the extra you actually get to use the full 200 AH with some to spare. Now if you have a pack that has cells that are like 180 AH and some with 220 AH then you may have some troubles but the cells don't come that way new. They just don't come with such a large variance. 

Pete


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## JRP3 (Mar 7, 2008)

I'm talking about the extra capacity between 210 and 220 ah, you can only use up to 210 ah. Simple fact is the cells will likely track more closely over time if they are at the same capacity. OEM's are concerned with matching cells and so should we. Remember the video from Jay Whiticare and what he stressed? Match those cells. I'm taking his advice. Until someone reports what their batch of TS cells come in at we don't know how close they really are. We do know how close the recent batches of CALB's are, and we do know that previous batches of TS cells have not been as close. Hopefully the new ones are closely matched. Pick whatever cells you want, but I'll continue to recommend that people get closely matched cells, just as Jay Whiticare did. Also the extra cycle life of TS is projected, not documented as far as I know.


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## Guest (Mar 18, 2011)

So your expecting to use that extra? That is like adding a couple more batteries to your pack because your controller can handle two more batteries but it's pushing the threshold. I buy 100 AH cells and if there is more in there then great. They are not 210 or 220 AH cells, they are 200 AH cells. There is built in extra so you can use that to your advantage. Well if you need to know how well balanced they are why not ask them. I won't use my cells in that manner. I will build for a 200 AH pack, not a 210 AH pack. So all the cells do fit within the 200 AH range so are matched quite well. If you match them at 210 then the 200 AH cells are lower capacity and those are your limiting factor. So you have cells at 210 and 220 and all are in this range? You do have a fully matched 200 AH pack. If you want 220 AH cells then you must contact them and order a fully matched set at that AH range. It will cost you, I guarantee you it will. If I find my cells are in the 90 to 100 AH range then I have a pack that is balanced at 90 AH and not at 100. If I have a batch of batteries that are over 100 AH then I have a pack that is balanced at 100 AH. So I don't use the extra. No big deal. I only paid for 200 and planed on 200 so I put it all together at 200. All will provide 200 AH. That is good. 

Pete


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## Guest (Mar 18, 2011)

You do know that Winston Battery company is the leader in these cells. What makes you think that they are not balanced from the factory in voltage and AH ratings? More likely who makes you think that? Who are you following? The Trolls (who by the way have taken over a few forums but left their mark) or those who are really doing and showing? 

Aren't you running lithiums? 

PS. Did you notice how quiet the forum has gotten since the main daddy trolls left?


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## JRP3 (Mar 7, 2008)

You're missing the point. No I don't use the full capacity potential most of the time. However the farther apart the cells are in actual capacity the different SOC each cell will actually operate at. If you have 100 ah cells where some are at 110 ah and some are at 120 ah, even if you only charge to 100 ah that means the 110 ah cells are at a higher SOC than the 120 ah cells. That also means the smaller cells will be putting out higher relative C rates than the large cells at the same current draw. All this can add up to different aging characteristics over time, which is probably why Jay emphasized matching cells. He's the expert, not me, I'm just following his advice. As for capacity variation for TS cells I'm going by what people have been reporting, just as I'm going by what people have been reporting for recent CALB orders. Maybe TS has improved their cell matching for each order, but I have not yet seen reports of such. I'm well aware of the relationship between CALB and TS, the fact is that CALB had better QC and cell matching than TS at one point, regardless of who licenses what.


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## Guest (Mar 19, 2011)

If all my cells are rated at like 110 and all fall within that 110 range + or - a few AH's and I put in 100 AH then That is all they will have in them. They won't have more than what I put in. If I have a glass that can hold 110 ounces and I only put in 100 then 100 is what I get out. They will always hold that if my filler container can only hold 100 ounces. I fill up each cell to 100 and that is all each will give. I just have some spare room. So it won't matter if a cell can hold extra cause your not using it, right?

I think I have the point pretty clearly.


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## Guest (Mar 19, 2011)

> I'm going by what people have been reporting


Yea! My point is WHAT people are reporting that? Are your batteries capacities that far out of whack? Very very doubtful. Mine on the other had are but only because some were abused badly and have a lowered capacity. I must cull out those with capacities way lower than the rest. Mostly I have found only a couple and the capacity is not off by much. The SOC is off by a lot but that is being fixed. I still have a bunch of cells that are needing balancing because of past abuse and were used with a malfunctioning BMS system. It is just time consuming to bring the SOC to a respectable level and then charge the packs. I am leaving many alone for now while I mess with the MG and Ghia. I am not putting on loads of miles either right now because of weather. The open MG is not the most fun in cold wet weather. We are getting a good soaking this week.


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## MN Driver (Sep 29, 2009)

gottdi said:


> If all my cells are rated at like 110 and all fall within that 110 range + or - a few AH's and I put in 100 AH then That is all they will have in them. They won't have more than what I put in. If I have a glass that can hold 110 ounces and I only put in 100 then 100 is what I get out. They will always hold that if my filler container can only hold 100 ounces. I fill up each cell to 100 and that is all each will give. I just have some spare room. So it won't matter if a cell can hold extra cause your not using it, right?
> 
> I think I have the point pretty clearly.


As far as capacity goes, that is correct, it won't matter because they will drain down at the same rate but if you have one that has a capacity of 110 when fully charged and one that is 100, when you draw them down and you are pulling, say 300 amps, you draw 3C from a 100Ah cell and 2.7C from the 110Ah cell. The 100Ah cell will generate slightly more heat which is wasted energy and slowly over time that wasted energy adds up to imbalance. The bigger the capacity difference or impedance mismatch with a pack, the bigger difference it makes. Of course usually you don't draw constantly at a high rate to where the cells get hot so its not as big of a deal as you might initially think but its a factor. If you had a bigger disparity amongst the pack, it would require a little more attention every xx cycles. This is the primary source of lithium cell drift, there isn't much of it, but its there, energy lost at heat with different rates between cells.


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## JRP3 (Mar 7, 2008)

> I think I have the point pretty clearly.


No I'm afraid you really don't. Read my last post again. Different sized cells filled with the same amount of amp hours will be at different states of charge. That is an imbalance that will be repeated every cycle and possibly be amplified over time. Minimizing this difference seems prudent, and what the OEM's are doing. We want our cells to all behave the same, the best way to do that is for them to have the same capacity and ideally the same internal resistance. My pack of SE/CALB cells came in between 110 and 114 ah actual two years ago, pretty close, but newer CALB shipments have come in with less than 1% variation, even better.


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## Guest (Mar 19, 2011)

Oh yes I do. If I fill each cell to it's own capacity then I will have troubles if my capacity is different and I drain to the end of that in a pack that is strung together. In reality that is not what happens. We charge the pack as a whole. 

Say I have a pack of 10 cells that range in capacity of 110, 109, 110, 104 and so on for all 10 and I put in a 100 AH level all at the same time in the string then the total fill level will only be 100. Not 110 or 109 or any such thing. If my stop level is 100 then ALL cells will be at the same capacity all the time every time if I use 100 as my stop level. If I change that level to 105 then some of the ones that are 104 will overflow or overcharge. But we don't charge cells one at a time now do we. We charge them in a string as though it is one single cell of a specified voltage and if you put in more than the minimum cell can hold then you over charge those cells. If all the cells can safely hold 100 or 200 AH then ALL the cells will MATCH in capacity but in reality they all can hold more. If I fill them to the same level each time and I leave enough safe room then the changes in temp and other factors then all the cells will maintain a balance. So far no one has really found that these imbalance due to the variances but the theory is sound. Even your saying its possible and not for sure. If it ever becomes a problem it is most likely that the cells are reaching the end of life anyway and its time to change them out. This is after many years of successful driving with no apparent discrepancy in balance. 

There is no imbalance if one fills to a safe level. But if you insist that you take the cell to the limits then maybe you will have troubles. Maybe. 

A 200 AH cell is showing 220 AH but since they are 200 AH cells I set my limits to 190 AH for both charge and discharge cycles and live in that zone. There will be no problems. Sure I am not using the full capacity of the cell but that is the goal too. Longer cell life. 

Pete


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## Guest (Mar 19, 2011)

> the best way to do that is for them to have the same capacity and ideally the same internal resistance.


In a perfect world. Yes that is true but what we are getting IS GOOD ENOUGH. So you really tested them all? Real accurate or guesstimate? Within those ranges of AH capacities your SOC will be so close and if you use the same method to charge each and every time you won't have trouble. 

I guess it is really important to be anal about making sure all our batteries are absolutely perfect in capacity and resistance. So if you really need that level of accuracy then you need to work with the company to be sure all cells are all fully matched and perfect for every order that comes out of the doors. There is fudge room for a reason. It might be needed to have that level of accuracy if we were talking about taking these to mars. But for our cars on the street the accuracy is not required. 

Pete 

SOC is relative anyway.


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## ElectriCar (Jun 15, 2008)

gottdi said:


> In a perfect world. Yes that is true but what we are getting IS GOOD ENOUGH. So you really tested them all? Real accurate or guesstimate? Within those ranges of AH capacities your SOC will be so close and if you use the same method to charge each and every time you won't have trouble.
> 
> I guess it is really important to be anal about making sure all our batteries are absolutely perfect in capacity and resistance. So if you really need that level of accuracy then you need to work with the company to be sure all cells are all fully matched and perfect for every order that comes out of the doors. There is fudge room for a reason. It might be needed to have that level of accuracy if we were talking about taking these to mars. But for our cars on the street the accuracy is not required.
> 
> ...


I wouldn't call that anal but the closer they are matched, particularly in IR the longer they will stay in balance which I think is a good thing. Mine all came in at .025-.030 with the vast majority .025 & .026. I added a spare at the last minute and it was tested at .036! At first I thought that wouldn't be good if I mixed it in but likely by the time I need to use it, the IR of the others will have increased due to age and ???


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## JRP3 (Mar 7, 2008)

gottdi said:


> Oh yes I do.


No you don't. The amount of charge you put in does not change actual capacity. That's like saying if you fill an 8 ounce glass half way it's now a 4 ounce glass. If you put 100 amp hours into a cell that can hold 110 amp hours and another that can hold 120 amp hours the smaller cell is at a higher SOC, period. We know that the more charge you put into a cell the less cycle life you have, so each time you are putting more relative charge into the 110ah cell than the 120ah cell. That means the smaller cell will degrade faster by being more fully charged than the larger one over time. This assumes bottom balancing of course. Top balancing puts all cells at the same SOC but the smaller cells will be more deeply discharged each time, which also shortens cycle life. The way to avoid both problems is to get cells as closely matched as possible. CALB ships all cells with data sheets showing actual capacity and internal resistance so you know what you are getting. Does TS do the same? Additionally Jacks testing showed the CALB cells to have flatter discharge curves, if he didn't get the free donation from Winston he'd be using CALB as he originally planned.


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## Guest (Mar 19, 2011)

I do. It is only relative. That 110 AH cell CAN hold a higher SOC but if I do not put in that extra it is not at a higher SOC. SOC refers to the state of how full a cell is during the charge or discharge of the battery. 

Relative to each other yes but we are not using the SOC. It is only a meter to tell us how full or empty a cell is from our fill level. It does not matter. Since all are filled at the same time the level is the same. They will empty pretty much the same too. 

I am very aware of the relative aspect but I am talking of what we actually use. If all the 110 AH cells are filled to 100 and that 200 AH cell is filled to 100 then we have a relatively 100% full Pack.

If I put into my pack a 200 AH cell and charge the pack of 100 AH cells then relative to the 100 AH cells the 200 AH cell will be at 50% SOC. That cell won't take the brunt and drain in half the time. It will just never be more than 50% charged and will live quite happy with the batch of 100 AH cells. 

So there is nothing bad happening here but you make it sound like there is. 

A major difference in IR may be an issue but I don't think it will be as big an issue as your making it out to be. Sure it is good to be as close as possible to ideal and I think the ideal is already in play. It will never be perfect but so far no one has complained about IR being a real issue. Could it be? Sure. Is it? Most likely not. Will cells drain a touch at differing rates? Yup. It's like that with all chemistries. Internal Resistance is a player but if you don't abuse the cells and run them in the range expected from the manufacturer they will be just happy as little clams on the beach. The manufacturer knows the differences and has given a parameter range in which to operate the cells. If you go out of the range you can run into trouble. It is up to you to set up your pack so it will stay within that range with known issues. 

As the cells get better and things get more accurate the parameters will change and our setups will change. But you will always have to run the cells within the parameters of the cell no matter what. Go out side that mark and your asking for trouble. We have lots of guys wanting to take them outside that parameter and that is not a good thing.

It's always push to the limits and bitch when it does not work. 

Pete 

Enjoy your cells as they were designed. The surpass all others that have been available to the public. But in the end it is never enough is it!


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## Guest (Mar 19, 2011)

CALBS are used in Aviation and as such the aviation industry is always more anal about precision so it is no wonder that CALB is a bit more accurate and refined. Also more expensive. So in order to get the better you will pay more. like I said and another too. What we have IS GOOD ENOUGH. It will get better. But even in its early days these cells surpassed any other ever available to the public. Note I said (PUBLIC)


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## JRP3 (Mar 7, 2008)

You still are not getting it. A 110ah cell charged to 100ah is at a HIGHER SOC than a 120ah cell charged to 100ah. Let's make the math really simple. A 100ah cell charged to 90ah is at 90%SOC. That same cell charged to 80ah is at 80%SOC. 90%SOC degrades a cell faster than 80%SOC. Same thing is happening with the 110ah and 120ah cells, the smaller cell is at a higher SOC than the larger one when charged to 100ah, or 90ah, or whatever. The smaller cell will always be at a higher SOC than the larger one when filled with the same amount of amp hours.
Yes today's cells are good enough, never said they weren't, but to make them last longer, and to make it easier to do so, it's better to get them as closely matched as possible, just as Prof. Jay recommends and just as the OEM's are doing. We should all request cells as closely matched as possible from all suppliers. More educated and demanding consumers leads to better products.


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## Guest (Mar 19, 2011)

> A 110ah cell charged to 100ah is at a HIGHER SOC than a 120ah cell charged to 100ah.


Relative to the 110 AH cell. In use we still can only take out 100 AH because that is all that was put in. Yes the 120 AH cell will last longer by a bit because it is being used at a lower total state than the other. This is where the fudge factor comes to play with a pack that has varying capacities. Fill the smallest one to a safe level and the rest are just along for the ride. 

I agree that the closer the capacities and IR the better. 

Never thought different. What I get is that folks talk like it is going to be a problem. Well if you don't do things correctly then yes.

So, Yes I do understand. I have always understood. Pretty simple really.


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## Roy Von Rogers (Mar 21, 2009)

If you had 10 buckets with the same diameter and one holds 5 gallons of water before spilling over, but the rest were all taller in some way, and you had them all connected at the bottom.....now you fill them til the 5 gallon bucket was full....you would have a total of 50 gallons of water available.

The taller buckets have no meaning, for all you can get out of the total, without spilling one over, is what the smallest bucket can hold.

If you have an empty battery pack of 100ah batteries, and you charge them to the 100ah rating, or to the smallest one in the pack, its full.

The few that are some amount higher, are not usable, no matter if you bottom balance or top balance. The only SOC one is concerned about is whats usable.

Roy


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## rfhendrix (Jan 24, 2011)

Roy Von Rogers said:


> If you had 10 buckets with the same diameter and one holds 5 gallons of water before spilling over, but the rest were all taller in some way, and you had them all connected at the bottom.....now you fill them til the 5 gallon bucket was full....you would have a total of 50 gallons of water available.
> 
> The taller buckets have no meaning, for all you can get out of the total, without spilling one over, is what the smallest bucket can hold.
> 
> ...


What then is the effect on battery life in that scenario (overall pack and individual cells)?


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## Guest (Mar 19, 2011)

The cells with more available capacity will last longer due to not being charged fully. In other words the SOC is lower than the ones that hold less. But the ones that are pretty much near full SOC will last the normal life span. The others will give more. It is best to have each container hold nearly the same so after a full life the cells are still pretty much balanced. From the factory they pretty much are the same. I think that the IR is the more critical part of this equation. 

It is interesting to note that I have a cell in my pack that will jump in voltage to a higher level before the others but in the end it was nearly the same before shutting down the charger. That cell has a spot that will just jump then settle down to the level of the others. It is interesting to watch the cells charge up. They don't charge at the same rate but pretty much close.


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## JRP3 (Mar 7, 2008)

Roy Von Rogers said:


> The only SOC one is concerned about is whats usable.
> 
> Roy


I'm not talking about using the extra capacity of larger cells, you're missing the point. Percentage of charge has an effect on the battery. The greater percentage you fill to the greater the effect on cell life. The greater percentage you discharge to the greater the effect on cell life. SOC measures percentage, not amp hours or capacity. With a bottom balanced pack a 100ah cell charged with 100ah's is at 100% SOC. A 110ah cell charged with 100ah's is at 90% SOC. Same amount of amp hours, different SOC. The larger cell charged with 100ah's at 90% SOC will last longer than the smaller cell charged with 100ah's at 100% SOC because the higher the SOC the greater impact on cell life. Again, this example applies to a bottom balanced pack. If top balanced then the imbalance shows up on the bottom when discharging. The 100ah cell putting out 100ah's ends up at 0 SOC and the 110ah cell putting out 100ah's ends up at 10% SOC. The cell with the lower SOC also negatively affects cell life. Over time these differences will add up and cause cells to age differently, which will further accelerate those differences. No BMS can counter that effect but getting closely matched cells to begin with can. Smaller capacity cells will always use a greater percentage of their capacity however they are configured, and the greater percentage of capacity that gets used the larger the effect on cell life.


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## JRP3 (Mar 7, 2008)

gottdi said:


> Yes the 120 AH cell will last longer by a bit because it is being used at a lower total state than the other.


This has been my entire point. Smaller cells will age faster than larger ones, which will in turn reduce their capacity more, accelerating the difference. Undercharging everything helps but cannot eliminate this difference, the large cells charged to 70% will last longer than the smaller ones charged to 75% for example. Over time this difference will still increase. Minimize these differences enough by getting closely matched cells and it won't be an issue. I'm guessing around 1% difference is good enough but at this point we don't really know.


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## Guest (Mar 19, 2011)

Don't top balance your cells. Just buy them and charge them and go. You do need to watch them for a few cycles to be sure they all fall within a normal range. They should with no intervention. Don't discharge your new pack first. You need to charge it up first. NOT top balance. There will always be some variances but they should be very very very closely matched from the factory. 

I fully agree that cells should be well balanced and if your truly concerned then you need to contact the company and have them log every cell capacity and IR and SOC from the factory and to be sure that they all match. Expect to pay more because it will take some effort to IR and Capacity match a set of cells for you.


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## Guest (Mar 19, 2011)

> Smaller cells will age faster than larger ones, which will in turn reduce their capacity more, accelerating the difference.


No, the smaller cell will last the normal time and the others will just last longer. The higher one can't affect the lower on at all. The life of the low cell is the life of the group. It sounds like your saying that the cell with more capacity will cause the lower capacity cell to actually age faster than normal. If you set your pack up to operate within the factory specs then it will last as the factory states. Might even last longer. But the one with more capacity can't make that low cell actually age faster. 

Pete


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## Guest (Mar 19, 2011)

Larger cells age slower than the smaller ones that age normally.


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## JRP3 (Mar 7, 2008)

gottdi said:


> Don't top balance your cells. Just buy them and charge them and go. You do need to watch them for a few cycles to be sure they all fall within a normal range. They should with no intervention. Don't discharge your new pack first. You need to charge it up first. NOT top balance. There will always be some variances but they should be very very very closely matched from the factory.


I never said you should top balance, or bottom balance, I was just using them as examples to clearly point out the differences of the effects in cell capacity and relative SOC.


> I fully agree that cells should be well balanced and if your truly concerned then you need to contact the company and have them log every cell capacity and IR and SOC from the factory and to be sure that they all match. Expect to pay more because it will take some effort to IR and Capacity match a set of cells for you.


My point is it should be common practice to sort cells in that manner at the factory. CALB, and I suspect TS, already measure capacity and resistance of each cell as part of QC so it's a simple matter to group like cells together.


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## JRP3 (Mar 7, 2008)

gottdi said:


> No, the smaller cell will last the normal time and the others will just last longer. The higher one can't affect the lower on at all. The life of the low cell is the life of the group. It sounds like your saying that the cell with more capacity will cause the lower capacity cell to actually age faster than normal. If you set your pack up to operate within the factory specs then it will last as the factory states. Might even last longer. But the one with more capacity can't make that low cell actually age faster.
> 
> Pete


Never said the larger cells would do anything to the smaller cells, I said the differences will be exaggerated as time goes on. These differences will probably lead to an imbalanced pack, we just don't know the effect over time.


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## Guest (Mar 20, 2011)

> My point is it should be common practice to sort cells in that manner at the factory. CALB, and I suspect TS, already measure capacity and resistance of each cell as part of QC so it's a simple matter to group like cells together.


Well it does cost money to group and measure for EACH cell. I'd expect if you wanted that you'd have to pay for that service. I would not expect any different. I think the manufacturing process is pretty darn close and that there should be some checking of batches but not always every single cell. That is very time consuming and can become very expensive to pay to have that level of perfection. 

If you want it I'd hope that they would charge a nominal amount for that service so you can have a well matched pack. 

I know you never said to top or bottom balance. I was just trying to be more or less generic and not say YOU in particular on that. That was not the way it was meant to come across. 

I'd like to see how close new batches really are. I'd bet they come pretty darn close. Now if you were talking Hi-Power I'd say be up front on what you want. I'd say those guys are less interested in QC than CALB or Winston. 

Pete


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## MN Driver (Sep 29, 2009)

gottdi said:


> No, the smaller cell will last the normal time and the others will just last longer. The higher one can't affect the lower on at all. The life of the low cell is the life of the group. It sounds like your saying that the cell with more capacity will cause the lower capacity cell to actually age faster than normal. If you set your pack up to operate within the factory specs then it will last as the factory states. Might even last longer. But the one with more capacity can't make that low cell actually age faster.
> 
> Pete


"The life of the low cell is the life of the group."

No, it's not. If the first cell in the pack reaches end of life for whatever reason, remove it or bypass the cell, adjust the charging voltage and keep driving because the rest of the group is going to be fine once the first cell fails. You will lose the capacity of that one cell and have a slightly lower pack voltage but if it was your lowest capacity cell and the next lowest capacity cell is a bit better than this one was, it might not be so bad. 100Ah cell is only going to be 320wh anyway, so a mile or mile and a half or so depending on the efficiency of the conversion.


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## JRP3 (Mar 7, 2008)

gottdi said:


> Well it does cost money to group and measure for EACH cell. I'd expect if you wanted that you'd have to pay for that service. I would not expect any different. I think the manufacturing process is pretty darn close and that there should be some checking of batches but not always every single cell. That is very time consuming and can become very expensive to pay to have that level of perfection.


Every cell is already tested for capacity and resistance. It has to be in order for them to know if they have a functioning cell and to see if it falls within specs. As Jack says it's an automated process. Each cell has a serial number on it. The only added effort is to include a copy of the data sheet with the cells. CALB cells are only slightly more expensive than TS last I checked, which probably has more to do with their flatter discharge curve and better density than the data sheet that comes with them.


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## Guest (Mar 20, 2011)

MN Driver said:


> "The life of the low cell is the life of the group."
> 
> No, it's not. If the first cell in the pack reaches end of life for whatever reason, remove it or bypass the cell, adjust the charging voltage and keep driving because the rest of the group is going to be fine once the first cell fails. You will lose the capacity of that one cell and have a slightly lower pack voltage but if it was your lowest capacity cell and the next lowest capacity cell is a bit better than this one was, it might not be so bad. 100Ah cell is only going to be 320wh anyway, so a mile or mile and a half or so depending on the efficiency of the conversion.


Well yes a cell can crap out for what ever reason and yes the rest of the cells are still good and you can marry in another to keep it all going. I do think you know what I meant. The low cell is the limiting factor until it craps out or a cell craps out and you have to marry in another. I am not in any disagreement with that.


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## Guest (Mar 20, 2011)

JRP3 said:


> Every cell is already tested for capacity and resistance. It has to be in order for them to know if they have a functioning cell and to see if it falls within specs. As Jack says it's an automated process. Each cell has a serial number on it. The only added effort is to include a copy of the data sheet with the cells. CALB cells are only slightly more expensive than TS last I checked, which probably has more to do with their flatter discharge curve and better density than the data sheet that comes with them.


Yes that is true but there is still work to do to gather and go through all the information to sort out the closed matched cells. It is not fully automated when it comes to that. Yes testing is done in the manufacturing process to the degree that the machines need to do. The final sorting will need to be done by hand and it will cost and I would charge for that level of balance. Even if you ask you may get that level of service and maybe they will do that for you for no extra. All you have to do is ask. Gotta remember that they don't just build a few cells at a time. 

Pete


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## jeremyjs (Sep 22, 2010)

Do any of the manufacturers, available to the public, make their cells close enough to matter? From what I've read if all the cells in a pack are within 1% or less of each other in IR and Capacity you can bypass the whole cell level bms/monitoring issue and simply treat the pack as one big HV battery. Only worrying about over charging/discharging on the pack level and not the cell level. After an initial balance, either top or bottom, of course.


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## JRP3 (Mar 7, 2008)

As mentioned the latest shipments of CALB cells have come in under 1%.


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## jeremyjs (Sep 22, 2010)

JRP3 said:


> As mentioned the latest shipments of CALB cells have come in under 1%.



Impressive


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## Guest (Mar 20, 2011)

> After an initial balance, either top or bottom, of course.


Not needed unless the cells are so out of balance in SOC that you have no choice. Load them up, charge them up and go. They do not need a pre top or bottom balance if they are within those close tolerances. If you pick up a badly managed batch of lithium cells like I did you have no choice and then bottom balancing is best. But new fresh from the box and if you got them as one single shipment I would not do anything but charge them up then use them. 

Pete 

At 1% or less your batteries are pretty good. My SOC for my cells were so out of whack that it has taken quite some time to find matching cells. I am hunting for matching in capacity as well as balancing them for voltage at the lower end. So far it is working. Just for me it's a slow process. I do work a full time job and have other interests too.


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