Don't hook your laser printer up to that 750. I have a 1000 just like that, but have it hooked to two external 12V batteries, so it weighs quite a bit less.

I have a 3.6KVA unit in the basement, but I haven't powered it on in about five years. It takes 72V, which is six 12V batteries, and I don't have them. The ones I did have went bad.