Yeah, more details needed. Were you plugged in, on the generator, or have the engine running? Was it in storage? If so, did you push the battery isolation switches?
Southwind systems are pretty much the same as Pace Arrow. The only time I clobbered all three batteries was the first time I used a cover when in storage and forgot to isolate the batteries.
Will & Di
2004 Southwind 32VS
Workhorse/8.1
Ford C-Max/Blue Ox
"We have met the enemy, and he is us" Pogo