Don,
I believe this is the inverter Cecil has:
APS750 If not, it is very similar. It is intended to be connected to the batteries at all times.
Let me know what you or anyone else thinks about these. I plan on getting a hard wired version of this brand for my back up system. This is the one I am looking at:
APS2424 This will only get wired into the watchdog system. With two of these, properly setup, I can run a 3 phase motor. Probably won't do that tho.
We've done the acid thing and it worked, but we're going way back in time