That is good to know. I should have stated a 13.5k as the biggest, but if it can handle a 15k BTU A/C, that cannot hurt.
I definitely won't be running the A/C directly off the batteries, but having the ability to essentially have an online (not standby) UPS that feeds all components a clean voltage regardless of what is on the other end of the wire is nice. This means not having to worry about an autoformer, although a surge protector is still a must. If the CG voltage is low and the batteries are making up for some of the load, I can always plug a second multi-stage charger into the 20A outlet and have the batteries charge via that.
