Heat your Lithium Batteries

[Scramjet]

Several people have asked about heating Lithium batteries in unheated spaces. This is true especially for the cheap china batteries where the BMS does not have a proper low temp cutoff. Most of the cheaper china batteries suffer from this condition. None of us want to ruin our batteries even if they are cheap. Further, even for those with a good BMS that does cut off, you may want to camp and charge in below freezing temperatures.

The obvious solution for full timers is to install the system in a heated space. But for part timers who don't heat their rig full time it is a problem. It is enough of an issue that Battleborn has developed a heated battery solution that is now available (at a price).

So... I ran an experiment last night (and I love a good experiment). I ordered a cheap 12w silicone heat pad, a cheap temperature controller and some thermal adhesive tape from Amazon. I thermal taped the heat pad to the side of a lead acid battery, connected the temp controller to the negative post and put it all in a factory battery box. I then put the box inside a plastic storage tote overnight. To monitor the test I put an outside sending unit from a weather station on top of the battery. The controller was set to turn on at 5 degrees C (about 40 F) and turn off at 10 degrees C (about 50 F). After a 30 degree F night the morning temp on top of the battery was 52 F and the controller temp at the negative post showed about 46 F. It seems to be cycling and working!!!

Conclusions: It does work. I would test it quite a bit more before I trusted it to guard $1,000 - $2,000 worth of batteries. Battleborn does have an off the shelf solution. The energy consumption when on is about 1 amp. On time will depend on the ambient temperatures and the enclosure.

Concerns: Robustness and longevity of the design and connections. Power consumption. Thermal conductivity of the case. Tightness and insulation of the enclosure.

I hope this helped or encouraged others to try this as a potential solution.

Regards, Brian