Batteries may have been done in because the inverter was running your 30 amp side, including the outlet your CPAP was on, rather than your actually having any power at the park post. If memory serves, our genset starts off the chassis batteries, but on some rigs it's off the house set. Since the first thing the generator does is charge the house set, it would seem better to have it start off the chassis, since as in your case the house set can be too far dead to start the generator in the first place.
Your words: "The 30 Amp is hot, but the 50 is not." Keep in mind that that could imply the inverter had taken over, not the power post, and was running its normal 30 amp breaker box components. Are you sure now that your power is 50 amp and coming from the post, or the generator? Just starting the engine I'd not expect to fix that, other than to BIRD over to charge the house so the genset would start.
I still think your park personnel need to check your post. Otherwise there is the unusual chance it is your transfer switch that's not passing power through. Did you try plugging into the 30 amp outlet on the power post?
Joel
