"dead chassis battery even though we'd been plugged into shore power overnight"
Chassis (engine) battery is isolated from the "RV" batteries. Being plugged into Shore power will NOT charge the chassis battery - at least that is the way I understand it.
You could have jumped the Chassis battery from one of the RV batteries to get the engine started (at which point the chassis battery is being charged). Or you could have removed the chassis battery and connected it to the RV batteries and let the Shore power charge the Chassis battery.
Gerry
