Hey Chris, the M925 down in Mt Airy had two 24-volt solargizers installed at one time for their quad pack of batteries...I presume you'll be running with two batteries, which should be enough IMHO.
Swyne, I would remove the batteries from the truck and keep the on the maintainer in the garage or somewhere cool within reach of the extension cord.
Lead-acid batteries have less self discharge when cold, but need to be fully charged to keep from sulfating...
Don't know much about solargizers, but they do need a lot of time to do their job and the original versions don't charge or keep the batteries "topped off".