When we picked up our "H" Oct 2004, we did a battery/auto-gen start test.
With 2 cruise airs on, the bedroom ceiling fan, lights, TV (tubed typed) and of course the frig, it took a little over 3 1/2 hours before the generator started. We thought not bad for all that load. So , we have no trouble making it thru the night and then some.
Had the house batteries load tested the first of the year, after almost 2 years, still in great shape.