Battery Heaters

Lithium battery technology is amazing for a van - high energy density, long life, and you can use almost all of the energy in them without damage vs only 50% or less for previous battery technology.

The only drawbacks are cost and the inconvenient fact that you cannot charge them below freezing. Some batteries have internal heating plates that use some of the batteries own energy to keep itself warm. Victron batteries do not so I created an equivalent system.

I modeled some aluminum heater plates and had sendcutsend.com create them for me. Then bought some bee hive heater pads off Amazon and wired them up. The Victron control system 'brain' (Cerbo GX) has a relay that can turn the heater pads on/off based on thermostat rules I setup. The Cerbo GX has a temperature input probe that is attached to negative battery post of the lowest battery (the coldest one).

When we're using the van in freezing weather, the heater will keep the entire interior and batteries plenty warm to take a charge. But the plates might be handy if we want to leave the van unheated for awhile (or put the heater thermostat very low).

In cold seasons, I'll put more insulation around all 3 of the batteries. But that's removable because in warm seasons, the batteries perform better when they aren't too hot so best not to install anything permanently over the top of them.