# Just got my Thundersky Lifepo4



## gss99 (Dec 31, 2009)

Hi. I just got my Thundersky cells. LP-20AHA. I haven't checked the voltage of each cell yet. How much time do I have before they need to be charged? Do I have a week or two? My charger is still on order. These are for an electric bike.


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## jondoh (Sep 8, 2008)

Relax, they don't self discharge like other chemistries. You have at least a few months-- probably more.


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## gss99 (Dec 31, 2009)

Thanks. I'm so worried about this. I don't want to have to go back to SLA. I'm going to the hardware store soon. Would appreciate anyone's help. 

Elite Power solutions sends out 12 Thundersky cells but 4 cells in each container. So I only have to hook up the 3 containers. Here is my list for when I go to the hardware store:

* 9 volt battery -- for my multi-meter (to check cell voltages)
* 10 gauge wire for hooking up the batteries
* 8 terminal rings ?? anyone know what they are called? They attach to the screw...they have hole in it so the screw goes through it and can be tightened down... I think the terminals are M1 terminals if that helps anyone

* Maybe some connector piece to hook unhook the batteries but I don't think that's needed because you guys said I could just charge them while they are hooked up in series. 

I'm going to use a 12v black and decker charger and charge each 12v container separately but while they are hooked in series. I think you guys said that will work okay.


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## frodus (Apr 12, 2008)

terminal rings = lugs

I think 10Gauge is a little on the small side.... thats just me.

those 12V lead chargers won't fully charge the batteries, they're not going to follow the right curve..... so they'll probably be a little undercharged, but it shouldn't hurt them.


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## gss99 (Dec 31, 2009)

ok, I got all the stuff I need. The screw will only take 14- 16 gauge ring terminals so I hooked 14 - 16 gauge ring terminals up to 10 gauge wire. Hope that will be okay. The 10 gauge ring terminals are way too big for the screw that bolts on to the thundersky cells. The amps coming threw won't melt that metal will it? 
Ok, also...I'm going to charge them with my black and deck like this....notice these two batteries are hooked up in a series. If I put the red on the positive on the one battery and the black on the negative of the SAME battery, it will work okay and not hurt anything or blow anything up? See picture


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## MN Driver (Sep 29, 2009)

Yes, that is how you should connect them up. It won't be an issue with shorting anything out or blowing anything up to connect it to the 4-cell battery like that.


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## gss99 (Dec 31, 2009)

Ok thanks. I got all 3 packs wired in series now. Do you think my multi-meter will handle 38v running through it? It handled 13v. I heard about someone blowing up their multi-meter and not sure how they did it. 

I measured one pack and it was 13.42v . So that means each cell is about 3.35 volts in that pack. Also, has anyone ever opened these packs before? I guess I could pull the top up with a screwdriver? I have to be delicate with it because I'm assuming there is wiring under there.


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## gss99 (Dec 31, 2009)

Ok...I duct taped all 3 batteries together so they won't slip around and come disconnected. 

Is the only way to short these lifepo4 batteries out to connect a positive and neg terminal together on the same battery or are there other ways? Is it just like lead acid in that way?


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## frodus (Apr 12, 2008)

gss99 said:


> ok, I got all the stuff I need. The screw will only take 14- 16 gauge ring terminals so I hooked 14 - 16 gauge ring terminals up to 10 gauge wire. Hope that will be okay. The 10 gauge ring terminals are way too big for the screw that bolts on to the thundersky cells. The amps coming threw won't melt that metal will it?
> Ok, also...I'm going to charge them with my black and deck like this....notice these two batteries are hooked up in a series. If I put the red on the positive on the one battery and the black on the negative of the SAME battery, it will work okay and not hurt anything or blow anything up? See picture


you got really small ring terminals then, the wrong ones. Go to Napa and see if they have copper lugs for 8 or 6 gauge. 10gauge wire is too small, it'l do 30A, and those TS cells will do more than that.... but it all depends on how many amps you're running through it. The smaller the wire and more amps, the more heat and resistance and more losses.

I'd say you should be using at least 8gauge, maybe 6.

as far as the charger, using a SLA charger with lifepo4 isn't recommended, but feel free to try. Just make sure it doesn't overcharge the batteries.


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## gss99 (Dec 31, 2009)

frodus said:


> you got really small ring terminals then, the wrong ones. Go to Napa and see if they have copper lugs for 8 or 6 gauge. 10gauge wire is too small, it'l do 30A, and those TS cells will do more than that.... but it all depends on how many amps you're running through it. The smaller the wire and more amps, the more heat and resistance and more losses.
> 
> I'd say you should be using at least 8gauge, maybe 6.
> 
> as far as the charger, using a SLA charger with lifepo4 isn't recommended, but feel free to try. Just make sure it doesn't overcharge the batteries.


Frodus, you said, "I'd go smaller but that's just me". That tells me that 10 gauge is okay. 

I got a more serious problem. I almost short circuited the whole battery. 

Ok, I didn't see any sparks but this is what happened. I've got all 3 batteries hooked up in series. I accidentally messed up in hooking up the anderson powerpole....so while it was still hooked up to the battery I unhooked those two leads....and I held one in one hand and one in another and I got shocked. I got shocked but would that kill the battery? I'm worried. It's been 3 min...how long does it take for me to know whether I blew the battery up?


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## gss99 (Dec 31, 2009)

I got a 35 amp controller. What about the wire between the individual 12v packs, is 10 gauge enough for that? Crap...I did all that work for nothing ??


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## gss99 (Dec 31, 2009)

I found some 8 or 6 gauge wire that I can use. Is it okay to use 10 gauge in between the actual 12v battery packs, though? I'd hate to have re-do all that work. There won't be as many amps running through those. Would there?


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## MN Driver (Sep 29, 2009)

gss99 said:


> Frodus, you said, "I'd go smaller but that's just me". That tells me that 10 gauge is okay.


I don't see him saying that quote at all. He was saying that he suggested 8 gauge or maybe 6 but that was before you said that you are using a 35 amp controller.
My personal opinion is that you will probably be able to get away with 10 gauge between the short runs on the battery as long as you aren't running the 35 amp load continuously on it. ...at the very least I'd stop after you've had the circuit under load(riding it) and check to make sure things aren't getting too hot at either the wires or the lugs.


> I got a more serious problem. I almost short circuited the whole battery.
> 
> Ok, I didn't see any sparks but this is what happened. I've got all 3 batteries hooked up in series. I accidentally messed up in hooking up the anderson powerpole....so while it was still hooked up to the battery I unhooked those two leads....and I held one in one hand and one in another and I got shocked. I got shocked but would that kill the battery? I'm worried. It's been 3 min...how long does it take for me to know whether I blew the battery up?


You managed to have ~36 volts pass through your body all the way from one hand to the other? These batteries usually can put out a tremendous amount of amperage, if you didn't get burned where the metal contacted your hands where you got shocked, then your bodies resistance probably didn't pass through enough amperage to damage the batteries. ...but be careful because whenever you have enough power to pass electricity from one hand to another with your heart in the path, you are putting yourself in lethal danger.


> I found some 8 or 6 gauge wire that I can use. Is it okay to use 10 gauge in between the actual 12v battery packs, though? I'd hate to have re-do all that work. There won't be as many amps running through those. Would there?


If you have access to the thicker gauge wire, I'd use it on those longer runs. The amperage will be the same throughout since everything is in series. The only amperage that will be different will be the amperage going between the controller and the motor.


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## Coulomb (Apr 22, 2009)

gss99 said:


> Frodus, you said, "I'd go smaller but that's just me". That tells me that 10 gauge is okay.


I think he may have meant a smaller number, not thinner wire. 6 gauge is thicker than 10 gauge.



> ....and I held one in one hand and one in another and I got shocked. I got shocked but would that kill the battery? I'm worried.


Take a chill pill, man!  The batteries will be fine; look after your self. You would have had about 40 V between those terminals; it's unusual, but not unheard of, that you would even feel that. Perhaps you were sweating a lot. Was the charger connected at the time? Maybe it was leakage from the charger, but that seems unlikely. Now you know that you can get a tingle from that voltage, respect it; avoid touching two wires at once.

You might have felt a milliamp flow for 2 seconds, or 2 mA.S (two milli-amp-seconds). Call it 10 mA.S tops. An amp-hour is 3600 A.S, so that was 10/3600/1000 of an amp-hour, or about 10/3600/1000/20 of your pack's capacity (14 millionths of a percent of capacity, if I got the maths right). So despite how sharp and energetic that shock would have felt, it's just nothing compared to the capacity of your pack.



> It's been 3 min...how long does it take for me to know whether I blew the battery up?


Unfortunately, damage to the pack is usually not easy to notice, unless it's really gross damage (like overcharging for an hour, then the pack could get really hot and possibly melt). You've done nothing bad to it so far, but if you eventually do, you almost certainly won't notice those extra weeks of life coming off the battery (e.g. by over discharging). But your pack has years of life, so even a dozen events like that are hard to notice unless you watch closely. However, they finally accumulate, and you might notice 10% less range as the first sign.

I can't think of an event that would "blow the battery up" in a matter of seconds. It will probably live through a complete short of say 2 seconds with only minor effect on life.


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## frodus (Apr 12, 2008)

> Frodus, you said, "I'd go smaller but that's just me". That tells me that 10 gauge is okay.


Never said that. 10gauge wire is too small. the larger the "number" the smaller the diameter. 18gauge wire is smaller than 10gauge wire.



> I got a 35 amp controller. What about the wire between the individual 12v packs, is 10 gauge enough for that? Crap...I did all that work for nothing ??


35A controller, then you DEFINATELY need at the very least 8Gauge. 10gauge will heat up too much (maybe melt) at 35A.



> I found some 8 or 6 gauge wire that I can use. Is it okay to use 10 gauge in between the actual 12v battery packs, though? I'd hate to have re-do all that work. There won't be as many amps running through those. Would there?


use 8gauge for ALL POWER LEADS from batteries to controller, and from controller to motor. That includes anything between the packs. Anything that is going to be carrying 35A of current needs to be sized as such. There's just as much current going through the wire in between the cells as is coming out. 



> Ok, I didn't see any sparks but this is what happened. I've got all 3 batteries hooked up in series. I accidentally messed up in hooking up the anderson powerpole....so while it was still hooked up to the battery I unhooked those two leads....and I held one in one hand and one in another and I got shocked. I got shocked but would that kill the battery? I'm worried. It's been 3 min...how long does it take for me to know whether I blew the battery up?


You got shocked with 36V of juice.... thats it. 



I think you NEED TO STOP WHAT YOU'RE DOING and read up a little on how electricity works, or get someone who knows electricity better than you do..... I wouldn't trust you with a lightbulb and a battery at this point. 

Stop just hooking things together hoping that i'l work. Thats a good way to get hurt or blow something up..... and ruin your batteries.


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## gss99 (Dec 31, 2009)

I know I don't know what i'm doing. Ebikes.ca sent me some wire to use on my bike. I compared the wire to the 10 gauge and they appear to be the same thickness. 

I'm tired. I spent all day messing with that stuff. I got it hooked up. 

Here is how it is hooked up. 

10 gauge wire from the battery ----> turnigy watt meter ---> 8 gauge wire??? ----> anderson connector ----> controller ----> motor

The only way I can disconnect the batteries easily is at the anderson connector near the controller. 

I bought another anderson powerpole but it's 50 amp industry strength and very hard to pull apart. Not to mention that for some reason the connection was bad so I took it off. 

What do I do now? I wish I could pay someone to do it. I would have bought 8 gauge but.........oh nevermind. Half the wiring from the battery to the controller is 8 gauge. Does that help ? Or is it still bad?


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## gss99 (Dec 31, 2009)

I know I don't know how to do this stuff. That's why I'm on here. Give me a break.


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## jorhyne (Aug 20, 2008)

gss99 said:


> I know I don't know how to do this stuff. That's why I'm on here. Give me a break.


Right. Questions are good. But most people ask them before they start playing with potentially lethal objects.


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## frodus (Apr 12, 2008)

anything carrying current, should be sized to handle 35A My rule of thumb is size 25% over.... so if you need 35A peak, size for ~45A, which would be 8gauge.

you need to use 8gauge between the three series batteries, 8gauge on battery +, 8gauge on battery -, 8gauge wire to and from the turnigy power meter, 8gauge to the controller from the anderson, and 8gauge to the motor.

throttle/keyswitch and all the other low power stuff can be smaller wire, but anything carrying current needs to be higher amp rated wire. 10gauge just isn't that big.


Oh, and you forgot ONE REALLY REALLY important thing.....

a Fuse.

And you should disconnect at the batteries, not at the controller. The closer the disconnect is to the batteries, the better.


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## gss99 (Dec 31, 2009)

I just re-did everything. My friend says 10 gauge wire is fine so I'm sticking with it unless something happens. I agree with him because the size that ebikes.ca sent and 10 gauge look exactly the same. 

Ok, here is what I've got now. The negative wire is hard-wired to the battery and the watt meter but I put a anderson powerpole on the postive wire. As long as the positive wire is not connected, the batteries won't deplete, right? So now, when I want to disconnect the battery, I can just unplug the anderson powerpole. The watt meter lights up when the powerpole is connected and isn't lit when it's disconnected so I assume the batteries won't deplete with this arrangement. Let me know, thanks.


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## gss99 (Dec 31, 2009)

the voltage on the pack says 39.78v. It's a 36v pack.


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## gss99 (Dec 31, 2009)

frodus said:


> I think 10Gauge is a little on the small side.... thats just me.


...............


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## frodus (Apr 12, 2008)

gss99 said:


> ...............


are you just not listening?

I said 10gauge is on the small side, which means, I'd go with a LARGER DIAMETER wire....As gauge number increases, diameter decreases. 8gauge is larger diameter than 10gauge.....which means it'l carry more amps. Sounds to me like you're just not listening.

Don't listen, in all reality, you'll likely end up smoking something, cooking the batteries with that charger, shorting something out or worse.



Why did you even come here and ask questions if you're just going to ignore the answers we all give you. We're trying to make the bike SAFE..... you just want it to WORK..... without regards to safety.


(BTW, I'm an electrical engineer and design lighting control systems for my day job, work as technical sales engineer working for EVComponents on the side, and consult for 2 other companies. I've designed..... 15-20 systems for people, and the same thing always happens. People think they know what they're doing, but they don't size the wire/fuse/diode/contactor/controller/motor correctly.)


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## gss99 (Dec 31, 2009)

frodus said:


> Why did you even come here and ask questions if you're just going to ignore the answers we all give you. We're trying to make the bike SAFE..... you just want it to WORK..... without regards to safety.


If you would have said, "no, don't get 10 gauge, that will absolutely not work". I would have gotten 8 gauge. That's the reason why I made the post to find out what to get before I went to the store. I came here to get good advice but when you say something like that. What am I to think?

That's like saying, "well, you could connect the postiive and negative of the battery and short it but I don't recommend it" . If someone said that, they'd be implying that nothing bad will come of that but they wouldn't do it themselves. 

I just went and checked on the gauge wire that I was using before with my 60v 9ah SLA and my 35 amp controller and it says "10 AWG" on it. And I never had any problems so I don't expect any now. 

I appreciate your help Frodus but that's pretty characteristic of most kinds of help that I've seen on the internet. People not answering questions. It's really hard to find good help on the internet. People answer 1/4th of the question or they don't say things clearly.


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## ahambone (Jan 13, 2009)

hipowerkevin said:


> Here's another choice of lifepo4 batteries----...
> I’m sure hipower batteries will be a better choice for you.


Can we get the above post flagged as spam? Clearly the posting party has not read the thread and didn't event take the time to understand what is being discussed. 

Cheers,
--Adam


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## frodus (Apr 12, 2008)

> If you would have said, "no, don't get 10 gauge, that will absolutely not work". I would have gotten 8 gauge. That's the reason why I made the post to find out what to get before I went to the store. I came here to get good advice but when you say something like that. What am I to think?


I did tell you that, several times. You just went ahead and used 10gauge. It will work for a little while at 35A, but its not "will it work", its "how long will it work before the insulation heats up too much".



> That's like saying, "well, you could connect the postiive and negative of the battery and short it but I don't recommend it" . If someone said that, they'd be implying that nothing bad will come of that but they wouldn't do it themselves.


I recommended a wire size based on the possiblilty that you could be drawing 35A continuous. I based my recommendations on known ampacity tables in worst case scenarios. 



> I just went and checked on the gauge wire that I was using before with my 60v 9ah SLA and my 35 amp controller and it says "10 AWG" on it. And I never had any problems so I don't expect any now.


Just don't go 35A for very long or the wires are going to start to heat up.


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## velocipede (Jul 29, 2009)

My opinion is that you are OK with your 10 gauge wire. There is no danger that the insulation will melt at that amperage. This wire can handle 55A. source: http://www.powerstream.com/Wire_Size.htm
You don't need to use the big anderson power poles. The regular 45A is enough.

I don't know your specific setup, but at 36V, you should have a top speed of about 40kph using around 10 amps. You will only pull 35A during the first few seconds of acceleration.

If you want more e-bike specific information, you can visit the endless sphere forum.


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## frodus (Apr 12, 2008)

I've seen NEC and NFPA codes that differ between 25 and 40A for 10gauge, depending on ambient temperature (the link above doesn't state temperature), and insulation type. I was going by an engineering book I have at my desk, and it says 30A..... NFPA says 40A, another says 55A.


How bout this, get the thing hooked up, ride around for 20-30minutes, if the wire is too warm to the touch, or you smell something melting/heating up, maybe think about switching to some larger gauge wire. Because until you know real life amp draw and how long that current is drawn, we're all kinda guessing.


Oh yeah, and the link for the endless-sphere forum is: http://www.endless-sphere.com/forums/index.php

great info for bike guys..... they'd answer most of your questions.


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## wenowhavepower (Dec 24, 2008)

I have an old (really old ~ 1950's book) Electric book and it has the following for 10 AWG:

```
[        Insulation (amps)           ]
A.W.G #   Rubber    Varnished-cloth      other
10         25                 30           35
```
This is from NEC (National Electrical Code).


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## patrickza (Dec 28, 2009)

I think Frodus is right, it seems like you're trying things you don't understand, and only then asking questions...

I can see you're not running a BMS. You will eventually lose cells this way. It's time for you to stop and to get your project planned on paper first.

Head over to the sphere and start a thread. The guys are very helpful and will be able to provide all the advice you need.


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## gss99 (Dec 31, 2009)

patrickza said:


> I think Frodus is right, it seems like you're trying things you don't understand, and only then asking questions...
> 
> I can see you're not running a BMS. You will eventually lose cells this way. It's time for you to stop and to get your project planned on paper first.
> 
> Head over to the sphere and start a thread. The guys are very helpful and will be able to provide all the advice you need.


I'm getting advice from a friend who has the same cells and has been running them for a year without a BMS without any problem. I tend to agree with user, Volkswagen, I don't think a BMS is really necessary. It doesn't make sense to pay $100 to protect a $380 investment when a 12v pack cost $120 anyway. I think you guys aren't considering the risk/reward ratio enough. If there's a 50 % chance that I kill cell after a year and a half and it's only $120 to replace 4 cells...or maybe even $50 to replace one cell, it just doesn't make sense to worry much about a BMS.


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## wenowhavepower (Dec 24, 2008)

Well depends, how long are you planning to keep the bike?
If for a very long time, investing in a BMS now, and using it for X amount of future packs replacements doesn't look so bad at all.


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## ahambone (Jan 13, 2009)

There are several advantages to having a BMS around. The BMS I'm using will work on basically any LiFePO4 battery - A123, HeadWay, SkyEnergy, etc. If I want to upgrade my pack to larger capacity cells or different cells it's no problem. The BMS I use is a kit developed by a couple of engineers over on the endless-sphere forums and was specifically designed for e-bikes; it works fine in cars too.

As a previous post mentioned, a BMS has significant cost. My particular BMS costs $75~$115 depending on the size of pack you put it against. For me that was a $115 BMS for a $2400 battery pack. The safety and peace of mind were well worth the extra 5% of cost. Plus it's fun to watch the lights when charging. 

I think the most important point is the risk/reward for the BMS. If you don't mind risking $ for cells later then skip the BMS. Several people have flown without one with no problems. They accept the risks.

If you want something that can run relatively maintenance free then LiFePO4 with a BMS is really the way to go, IMHO. The BMS saves you time, money, and suffering later in exchange for some $ and time up front buying and wiring it up.

Cheers,
--Adam


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