Lipo running temps

[Jesse J]

I know lots of us have heard and shared the common knowledge that lipos should not be used under 70degF. I just found a thread on a car forum where guys are running them in freezing temps and not reporting any issues.

Does anybody have some manufacturer links or source data on these two extreme temps where lipos are being used?

Could it be that with cars the draw is an order or two magnitude less and this permits lower operating temps? Whereas boats dumping so fast, need the higher temp?

[Jeff Wohlt]

They pull much fewer amps (except starts, etc) and run long times. I still do not see why they would do this. Our guys race the same packs all dam night and several heats and don't even charge them.

[Jesse J]

I still do not see why they would do this..

Not sure what you mean here... do what?

[exotica]

I would say it would be the temp/dump issue. We run brushless cars and never heat the batteries up prior to use. It would be great to know if heating the packs up for rcboats promotes the life of a lipo.

[Rumdog]

I have ran boats in 20 degree weather without pre-heating with no issues at all!

[Jesse J]

I have ran boats in 20 degree weather without pre-heating with no issues at all!

Allright, that does it, I gotta ask.....

WHY?? If you have to wear gloves, it is not boat weather...

[Jesse J]

OK, does anybody have any data that supports the flailing hypothesis that running lipos in cold temps damages the cells???

[Jesse J]

This just in:

Operating Temperature:

* Charge:
o 32 to 113 degrees F
o Let battery cool down to an ambient temperature before charging.
* Discharge:
o 32 to 140 degrees F
o During discharge and handling of batteries, do not exceed 160 degrees F.
* Battery Life
o Batteries that lose 20% of their capacity must be removed from service and disposed of properly.
o Discharge the battery to 3V/Cell, making sure output wires are insulated, then wrap battery in a bag for disposal.

Storage & Transportation:

1. Store battery at room temperature between 40 and 80 degrees F for best results.
2. Do not expose battery pack to direct sunlight (heat) for extended periods.
3. When transporting or temporarily storing in a vehicle, temperature range should be greater than 20 degrees F but no more than 150 degrees F.
4. Storing battery at temperatures greater than 170 degrees F for extended periods of time (more than 2 hours) may cause damage to battery and possible fire.

http://www.rctoys.com/pr/2006/10/20/...mer-batteries/

[Jesse J]

oops, double postage

[Doby]

We run ours in the cold up here all the time without pre warming them. They are slower initally untill they warm up for a few laps but seem to be no worse for wear.

[Fluid]

Something has been lost in translation. The reason not to run LiPos under ~70F in boats was due to their much higher internal resistance when cold. At high amp draws the cells could be damaged because of the internal resistance - overheating and puffing were reported. At low draws the temperature should not matter, and newer cells might not be as succeptible to damage..



.

[Jesse J]

Thanks Jay, I was wondering if it was something like that. I will still warm my batts for running boats, but might relax the temp range for the cars.