Thank you much. At the time I did this, I had the selector set to BOTH for all batteries - not sure if that is better or worse!
Anyway, I will either track down a volt meter or buy one. I am reassured though by your comments. Just another lesson learned I guess.
So the 'bad' part of starting while connected to shore power is what?? if no battery is selected? What is the issue? just for my knowledge.
Thank you again.