Electrics

When I plug my first 31.7 into shore power do all the electrics, ie lights,fridge, radio etc run from the shore power or from the boats batteries?

The issue I seem to have is that when I'm 'plugged in' we still appear to use battery power. Am I missing something?

Last week I spent a few days in Ipswich conected to shore power, but after a couple of days my battery was run down, ( I keep the engine starter batt off when not using the engine) so that was Ok, and the other battery soon charged up under engine power, but something tells me it shouldn't be like that.

I have power going to the battery charger, I have a switch on the electics panel that I'm not sure what it does but has 3 lights a rocker switch and the words DC under it.

I know this sounds a bit of a dull question, but basically I'm a sailer not an engineer of any sort!! and the bigger the boat the more complecated it seems to become...

Any advice would be really helpful.

John

John