How cold is too cold for lipo?

[RUSTY XL-5]

About this time of the year, I go on a lot of camping trips, and even some during the winter up in the northern states. Naturally, I want to take my R/C's along.

I was wondering what temp is too cold for a lipo before the batt becomes harmed? Also, do lipos have a specific temp at which they perform the best?


Thanks!

[jnev]

I have ran my lipo in about 15*f weather and they performed fine. I warm them a little before going out, and during the run they usually don't go below 85 - 90*F.

[jhautz]

Not sure I know the answer to what temp to low is.. but I do know that if you are running a pack that is cold... 50 degrees F outside and the pack is at air temp it has noticeably less punch. The internal resistance goes up the lower the temp which makes it less capable of delivering current effectivly lowering it true C rating at the lower temps. I tend to be on the safe side. What I have found to be a good solution in the colder months when I want ot run is a couple of those hand warmer bags (the ones when you break the seal inside they heat up for an hour or 2.) I toss a couple of those in a small cooler and keep the lipos inside there untill I'm ready to use them.

[RUSTY XL-5]

Originally Posted by jhautz

Not sure I know the answer to what temp to low is.. but I do know that if you are running a pack that is cold... 50 degrees F outside and the pack is at air temp it has noticeably less punch. The internal resistance goes up the lower the temp which makes it less capable of delivering current effectivly lowering it true C rating at the lower temps. I tend to be on the safe side. What I have found to be a good solution in the colder months when I want ot run is a couple of those hand warmer bags (the ones when you break the seal inside they heat up for an hour or 2.) I toss a couple of those in a small cooler and keep the lipos inside there untill I'm ready to use them.

I thought they would slow up when cold, and thanks for the cooler idea. I'll be using that idea this winter.



PS. I would really love to know (if somebody does) what is too cold for a lipo. That way I can leave them in my tent (protected of course) and not have to worry about warming them up until it is time to use them.

[jhautz]

Do you mean to cold to store them or to cold to use them?

I have heard of people storeing them in the refridgerator during extended periods of non use... but I dont know if that actually helps anything or not, but I dont think it hurts them. I wouldnt let them freeze or anything, thats for sure. And Id try and get them at least to a reasonably warm temp befor running them hard.

[lincpimp]

Or you can throw then in your inside jacket pockets... So people may be a bit hesitant to do that... I just put them in my pockets to warm them up!

[RUSTY XL-5]

Originally Posted by jhautz

Do you mean to cold to store them or to cold to use them?

I mean what is too cold to store them. I'm going to make sure they are warm before using, especially since I always drive hard.

[VintageMA]

Check out the ThunderPower Lipo Sheet here:

http://thunderpowerrc.com/PDF/THPSafetyWarnings.pdf

Middle of Page 2:

Storage & Transportation
1) Store batteries at room temperature between 40 and 7 0 degrees F for best results.
2) If storing longer than one week; batteries must be stored at 3.8V/cell to 3.9V/cell (approximately 50% charged) . This is easily
accomplished using the Thunder Power 1010C charger.
3) Do not expose battery packs to direct sunlight (heat) for extended periods.
4) When transporting or temporarily storing in a vehicle, temperature range s should be greater than 20 degrees F but no more than
150 degrees F.
5) Storing Lipo batteries at temperatures greater than 170 degrees F for extended periods of time (more than 2 hours) may cause
damage to battery and possible fire.

[RUSTY XL-5]

Thanks! Just the info I was looking for.