Warm up cold batteries before charging?

[hueman]

When stored cold (like down to zero Celcius), should batteries be warmed up to room temperature before charging them?
I know that before using them they need to be warmed up but for charging too?
@PatR @DoomMeister
Cheers.

 

[Eagle's Eye Video]

I would say yes....

 

[Phaedrus]

I would get them to at least room temperature before charging. Bring them into the house for a couple of hours.

 

[DoomMeister]

I know that it is recommended to let LiPo’s cool to ambient temperature before charging after being discharged and I believe that the preferred temperature be below 32C (90F).

I am assuming it would be best for the battery to warm up to a temperature above 15C (60F) for best results.

I have been charging mine in the garage in Florida with temps around 15C and in the basement in Michigan where the temp was about the same.

I’m quite new at this myself, but I think the veterans of LiPo usage will agree that I’m in the ballpark with my figures.

 

[PatR]

I would get them to at least room temperature before charging. Bring them into the house for a couple of hours.

Agreed. It’s also a good idea to avoid letting them be stored or cooled to 0C.

 

[Phaedrus]

Agreed. It’s also a good idea to avoid letting them be stored or cooled to 0C.

Especially since storing at that temp means I would have to go out into the cold to get them!!

 

[hueman]

Agreed. It’s also a good idea to avoid letting them be stored or cooled to 0C.

Oh? I read that storing them cold can work in our favor... "Reducing the storage temperature slows the chemical reaction of the aging/degrading process. There is a limit as to how cold is OK. Lipos don’t want to be frozen solid, but keeping them cool during storage is most certainly in our favor. It turns out the typically household refrigerator (37 to 40 degrees which is 2.8-4.4 C) is the perfect storage place."
Naturally I wouldn't let them freeze but the temperature may go down to zero overnight in which case I'd get them in and slowly warm them up.

 

[Phaedrus]

Within reason the storage temperature is less important than the storage voltage. Especially when you are using your packs semi-regularly. The issue with storing in a refrigerator is the potential for moisture buildup, especially on the contacts.

But regardless of your storage temp, prior to recharge I would bring them up to room temperature.

 

[hueman]

ok, thanks all!

 

[PatR]

I sort of figure that since manufacturers provide us with best operating and storage temps it makes sense to make use of their advice. None of them recommend storing at 0C.

I’ve also read posts from people extolling the benefits of super cooling their batteries prior to charging to obtain higher capacities but not once have I seen test data that included enough, or even any, A-B-A test results to support their claims. It’s easy to lay claim to a perception but providing proof to establish fact is a lot more difficult. One thing is fact and that is using a cold lipo generates higher resistance in the cells, which by itself reduces performance.

 

[Mrgs1]

I've read storing them too cold, can cause condensation when warming them up.