question

tomio avatar image
tomio asked

Lithium Battery warmers and heat pads

Hi, Just wondering what the latest info might be on heating your Lithium Batteries in subzero temperatures.

I did a search on the archives and found the following.

https://www.thermosensedirect.com/acatalog/silicone_rubber_mat_heaters.html

Just wondering if there's anything else that someone has tried and can recommend here.

Thanks


battery chargingLithium Battery
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2 Answers
wkirby avatar image
wkirby answered ·

I am getting away with just thermal insulation.
The lowest outside temperatures have been -10ºC recently. The outbuilding's inside temperature has gone down to 0ºC yet the battery temperature has not gone below 8ºC.
This battery charges from the network during the coldest times in the early morning. Charge power of about 30% of the battery's maximum charge power but it is enough to warm the battery up to 15ºC. The thermal insulation then keeps them warm for the rest of the day. Heavy discharge periods during the day will also cause them to warm up or at least retard the cooling, so the whole thing works passively.

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sebastian-k avatar image
sebastian-k answered ·

Hi,

I have placed a piece of 24 Volt Electric Underfloor Heating and a electrical PTFE insulation below my 8 prismatic LiFePo4 cells in my DiY battery. In my case its 0.6m in length resulting in ~15W. Additional thermal insulation is not yet installed. It takes ~5 hours to increase the temperature of the battery cells by 4...6K. This is not much but helps in some cold days to increase the battery temperature above 0°C before PV production starts.

https://www.amazon.de/Electric-Underfloor-Heating-Infrared-Assembled/dp/B08FCFQV8C?ref_=ast_sto_dp&th=1

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