Can LiFePO4 Batteries be charged below freezing

[rloveless]

I thought that you shouldn't charge LiFePO4 Batties below freezing temperatures. But I'm not sure what to believe anymore because...

- this site/company says that it's possible: "When charging lithium iron phosphate batteries below 0°C (32°F), the charge current must be reduced to 0.1C and below -10°C (14°F) it must be reduced to 0.05C."

Also this video shows that no damage was done when attempting to charge at low temps.

Also I thought I heard that some LiFePO4 cells being developed can operate below freezing temps. This battery has its low temp protection set at -40F with out a built-in heater. [Maybe this is an error on their part?]

I'd be curious about your thoughts or any documentation people have.

Thanks

 

[sunshine_eggo]

I thought that you couldn't charge LiFePO4 Batties below freezing temperatures. But I'm not sure what to believe anymore because...

- this site/company says that it's possible: "When charging lithium iron phosphate batteries below 0°C (32°F), the charge current must be reduced to 0.1C and below -10°C (14°F) it must be reduced to 0.05C."

I also thought I heard that some LiFePO4 cells being developed can operate below freezing temps. I'd be curious about your thoughts or any documentation people have.

Thanks

Freezing isn't a hard line. Below freezing, and the typical 0.5C rated charge current may cause lithium plating and loss, and it gets more dangerous as temperatures drop. Charging at lower temperatures at lower currents can be safe. Knowing now much current and at what temperature is the problem.

It's nice to see companies post that information. It's not common.

Yttrium doped cells can typically be charged safely at rated current down to -20°C.

 

[jasonojordan]

Also when its says 0c as the cut off for most for coldest temp to charge that is cell temp not air temp.