This is more for the record than anything, but I grabbed some gloves out of the back of the van and got a bleep from the CO sensor that usually means low battery.
I stuck my head in the side door and the BlueSky read 6v, which for my panel (always seems to read a volt low) is 7v.
The van has been parked since our last trip almost exactly a month ago, returned to the garage with full batteries and only the propapane and CO sensor on. I suppose it is reasonable that the sensors draw 1/2 amp together which would account for a month on 424 amp hours I have, but still it just always feels like I have way less power than I think I should.