Today I performed a temporary install of the 4 new batteries I've purchased for the Honda. These are in addition to the 6 it already has, thus making it a 120V system with ~12kWh pack (2o hr. rate). These four batteries plus the other two under the hood will be charged by two Dual Pro Recreational Series 3-Bank 6-Amp chargers. Each charger has 3 independent, isolated, microprocessor-controlled chargers capable of pushing 6 amps, which may be used in series or in parallel with each other. Here's a picture of the batteries wired up into a temporary 48V bank, with the Dual Pro chargers sitting next to them.
Also, I found out about a very economical way to control the temperature of batteries being warmed by battery heater pads: Water heater thermostats. These thermostats switch 120V AC, and handle the wattage of normal hot water tank heating coils. Perfect for the battery heater pads I've bought, which don't come anywhere close to the wattage of a hot water tank. And they cost less than $10 each, so you can afford to put one on each bank of batteries you'll be heating. That's important because different banks will have different thermal properties depending on their isolation from the outside environment. Here's a picture of a water heater thermostat I bought at Lowes, sitting on top of a Farnam battery heater pad I bought from KTA Services. The thermostat can control in a temperature range of 90'F - 150'F. Which is fine for lead acid batteries, since you probably want them warmed to about 100-120'F for best performance.
One thing Dave Cloud warned me about with the hot water tank thermostats, is to do one's best to isolate the thermostat from any possible gas the batteries might vent. This is due to the possibility that the contacts inside the thermostat could spark when making/breaking the circuit, which could ignite a concentration of hydrogen gas. While I assume this is more of a concern for flooded batteries than the AGMs I'm using, it's a valid point and one I will have to consider.
