I've been working on the alternatorless modification a little bit lately (installed an
onboard charger) and the thought has occurred to me that I will probably need to do something more for it to enable me to use it this winter. Last winter I didn't use the modification at all due to having an older battery that just didn't have enough capacity to do what I needed it to. However, now I have a new deep cycle battery and now is the best time to try to make it work during winter.
To enable good winter operation, we need to get the battery warmed up a bit. So, the first step to do this will be to get some insulation around the battery. I'll be able to fit ~1/2" polystyrene around the sides of the battery (unfortunately not the top or bottom as I'm space limited) to hold the heat in. In addition to that I'm looking at heating wraps for the battery. Kats makes a few, but the reviews on amazon aren't the best. Does anyone have any other recommendations?
Alternatively, it would be ideal to heat the battery with engine coolant, but that is a much more complex project unfortunately. Darin also mentioned to me a while ago about moving the battery into the cabin to share the heat from the heater. This definitely would allow me to keep the battery warmer during the day while the car is in the parking lot (not able to plug in anywhere). Also, any relocation of the battery would allow me to add more insulation around the battery to retain the heat better through the day.
Any other ideas are welcome!