Lipos and snowballs

[Evandiego]

All I'm running these days are Lipos. I know not to operate them above 60C/140F as they can catch on fire....is there a minimum? I've searched here but couldn't find anything relevant. Snow is gonna be here in 3 months.

What about in the winter time? It gets down to -30C/-22F in January where I live which I probably wouldn't be outside for too long...but what about using lipos when it's -15C/5F?

I've got Nicd's on standby if Lipo's aren't recommended below a certain temp.

Any tips would be cool!

[jnev]

I don't have experience running crawlers in snow, but when I run my brushless 1/8 cars in the snow there is noticable less power, however, as the pack warms up, it performs just like before. It may be a good idea to warm up the pack inside before heading out. The temps outside for me during running were between 5 and 30 degress fahrenheit.

[toytech93]

we have comps during winter in VA. Normally, we just keep our lipos in our pockets to keeps some temp in the battery.

I haven't had any problems yet.

[Rick Findley]

Yes, the cold has a definite effect on LiPo performance, sluggish. There are LiPo heaters available, made just for this problem. I solved the problem by sitting on them.

A fellow put a NiMih in his pocket as a ready battery for an enduro race we where having. He forgot to take out his keys and other contents of his pockets. He was quite a disruption on the driver's stand. Jumping, squirming shouting and cussing, nothing new for him, typical driver's stand antics. But, then the ghastly sight of him dropping his drawers! Yuk! Something shorted and burned a hole in his pocket, down close to the valuables. I have nixed that idea about a battery in my pockets ever since... no matter what kind of battery it was.

[Evandiego]

Originally Posted by Rick Findley

Yes, the cold has a definite effect on LiPo performance, sluggish. There are LiPo heaters available, made just for this problem. I solved the problem by sitting on them.

A fellow put a NiMih in his pocket as a ready battery for an enduro race we where having. He forgot to take out his keys and other contents of his pockets. He was quite a disruption on the driver's stand. Jumping, squirming shouting and cussing, nothing new for him, typical driver's stand antics. But, then the ghastly sight of him dropping his drawers! Yuk! Something shorted and burned a hole in his pocket, down close to the valuables. I have nixed that idea about a battery in my pockets ever since... no matter what kind of battery it was.

Wow that sounds unpleasant but funny nonetheless! Now I see the extreme benefit from soldering female deans on batteries. Maybe I'll just stuff them in my socks Lol!

So from what I gather it is safe to run Lipo's in -15C/5F just a little sluggish. My lipo's will probably outlast me before I have to go back inside and warm up.

To make sure that the physical and chemical properties of the batteries are not permanently altered if subjected to extreme cold temps, I will contact a battery manufacturer for sure and will post their response.

[helhedded]

Originally Posted by Rick Findley

A fellow put a NiMih in his pocket as a ready battery for an enduro race we where having. He forgot to take out his keys and other contents of his pockets. He was quite a disruption on the driver's stand. Jumping, squirming shouting and cussing, nothing new for him, typical driver's stand antics. But, then the ghastly sight of him dropping his drawers! Yuk! Something shorted and burned a hole in his pocket, down close to the valuables. I have nixed that idea about a battery in my pockets ever since... no matter what kind of battery it was.

just keep all other metal objects out of your pocket and you will be good.

I had some nimh rechargeables and my keys in my pocket once. Within a few minutes my pockets were getting really hot.

[JohnRobHolmes]

70f is a good minimum temp. Don't try to charge the packs if they are cold either, it can reduce lipo lifetime.

[Evandiego]

Thanks for the inquiry. The MSDS does not actually address cold temps but only high temps. I do know that the ideal pack temperature is about 90-110 degrees F when running. The pack will perform it's best while discharging at those temp levels. Higher temps cause more resistance from heat build up and I imagine that lower temps would just cause poor performance as the power flow may slow down. If the cold weather conditions prevented the pack from being able to get up to at least 90 degrees, then you may see a lack of performance. I hope that helps. Let me know if there is anything further I can help you with. Best regards!

Clint Preston
www.MaxAmps.com
1-888-654-4450 Toll Free

Hmmm...I guess you can't damage a Lipo from being too cold! But a loss in performance will be experienced like all other batteries....Now the question is which type of batteries (NiCd, Lipo, NiMh, LiFe, etc.) voltage is least influenced by cold temps?

[clockworks]

The problem with LiPos is that they don't generate a lot of heat in use, unless they are seriously over-stressed.

NiMH packs get quite warm during use. Keep a pack in your pocket, put it in the truck, and it'll probably keep itself warm enough to be OK in sub-zero temps.

A LiPo will probably get colder as you run, reducing power and run time.
Since it never gets more than 2 or 3 degrees below freezing here, I've not had a problem with my planes. They only fly for 10-15 minutes, so the LiPos don't have a chance to get too cold.
I've not crawled in winter yet.

[Evandiego]

Update: Ran a winter rally series every month for the past two years running lipos. No noticeable difference in delivery of power. Car punchy as hell. However, there is a slight decrease in capacity. I would say about 200mah from a 2S 2000mah battery. So expect 10% less in -15C (5F).