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Old 09-02-2008, 06:42 PM   #16
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Heating LiPO's really helps lower the IR of the pack. Tests have shown increases in performance(on track) over a non-heated LiPO. It doesn't seem to matter if the pack is heated during charge or after the pack is completely charged. As long as the pack is at the optimal temp when it's on it's way to the track. Die-Hard racers don't care if heating the LiPOs takes away cycles. It's all about performance.

Check with your track to see if there are any rules in place regarding pack temps. It's probably a good idea for tracks to put rules into affect to limit the heating and voltage of LiPOs. Extreme overheating and overcharging can cause swelling, destroyed cells and possibly FIRE!
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Old 09-03-2008, 08:08 AM   #17
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[QUOTE=Tubaboy;4797538]In Stock classes this isn't an option. For bashing, yeah it's not needed. But when racing, you can't add cells and if you're in a stock class, you can't run a hotter motor.

Aaah, okay. I wish I knew that because if I did, it would mean I have more than a clock to race against. Should've know something like that from me hydro racing days tho.
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Old 09-03-2008, 09:43 AM   #18
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Well we aren't really suggesting that you heat it to 170 degrees. Most suggest that you heat it up to 110 to 130. IIC had a limit of 110, and they had 0 issues.

On our track, during the summer, the track surface temp is in the 120s normal. This obviously warms up the pack on their own. And after a couple of warmup laps, the battery is well into the peak operating temp. But when racing on carpet, or on a cool day, definitely something that a few guys follow.

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Old 09-03-2008, 11:33 AM   #19
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I for one think this thread is a very dangerous one, especially when some people say it really helps getting more power out of your LIPO.
Since this is a very popular forum, this thread is going to reach enough idiots that are going to try to warm their LIPO because they think they can get somewhat faster if they have a little more power...

If you need more power, drop in a faster motor, if you're running 13.5 or 10.5 and you think you need more power, step over to modified instead of pushing your fellow racer to abuse his equipment to try to keep up with you.

It would be best if this backfires on a few with a big mouth down here that are saying this works in order to make sure this will not be a dangerous new way to get more power.
Oh, and telling people that it will give more power but you dont recommend it doesnt help, it'll just make em try. Just say it doesnt help... Oops, too late
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Old 09-03-2008, 11:40 AM   #20
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TrakPower endorses moderate warming as an acceptable practice. Ling provided some test data a while back that showed no ill-effects on cycle life when kept to a reasonable temperature. I think the IIC guys got it right with 110. Just be mindful of the temps if you're waring inside a Liposack, because they hold in a lot more heat.

If you want to be worried about something, how about guys removing the voltage clips from their GFX's to always charge to 8.44? That scares me more than a little heat.
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Old 09-03-2008, 12:20 PM   #21
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I am not a Lipo chemist or an expert of any kind. I find my information in a similar fashion as most of you...searching the internet.

In looking at Kokam's site it looks like the temps that were OK'd in Vegas are well with in the specs for Kokam cells.

http://www.kokam.com/english/product/battery_main.html

As for the practice of heating lipos...it seems like that is a standard practice in automotive grade lithium batteries. Watch this "How it's made" video and at the 3:40 mark they talk about placing heating elements in between the cells to keep them at operating temps.

http://www.youtube.com/watch?v=MqywKcJ0J2M

So I don’t think heating lipos are a bad thing, or dangerous if done right. The key here is having some sort of standard way for heating the packs, not just however someone figures out a way of heating a lipo. I’d like to see some guidelines about how to properly heat a lipo pack…not just by learning what not to do from the next recipient of a Darwin award
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Old 09-04-2008, 08:27 AM   #22
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Quote:
Originally Posted by Quante View Post
If you need more power, drop in a faster motor, if you're running 13.5 or 10.5 and you think you need more power, step over to modified instead of pushing your fellow racer to abuse his equipment to try to keep up with you.

It would be best if this backfires on a few with a big mouth down here that are saying this works in order to make sure this will not be a dangerous new way to get more power.
Oh, and telling people that it will give more power but you dont recommend it doesnt help, it'll just make em try. Just say it doesnt help... Oops, too late

Saying it doesnt help is not the truth. Running a differrent motor is not legal or sporting. I cant recall a time that I ever raced and didnt feel like I had to abuse my equipment just to keep up. I think thats just the nature of racing.

I dont really subscribe to the whole idea that you can stop an idiot from hurting himself by telling him something doesnt work. Lies typically dont improve a situation.
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