"How are you UPS'ing for 6 hours?"
Sorry I missed the "How" part at first:
Deep cycle motor boat wet batteries coupled to an inverter. Not recommended anywhere for home use but sure cheaper than dry batteries which cost at least twice as much for the same efficiency. I now have two 12 volts batteries and I used to have 4. They are around 100$ a piece and I change them every 6-7 years or so since the power rarely go down around here so they last a long time. Most of the time, they cycle when I simulate a power outage to test the batteries. 1 hour power out test every 2 month and one test until the batteries are drained like once every six months or so.
Use at your own risk, I don't recommend or endorse anything here