battery problems

My house batteries are Group 24 12-volt deep cycle from West Marine. I got them in the spring of 2017. They are serviced each fall and put on a trickle charger. As soon as I turn off the battery charger at the dock, or shut the engine down, the indicator on my instrument panel shows a pretty...

I have a 1980 C27 Catalina. My batteries have gone dead while plugged into the shore power. Shore power was attached, 120V circuit breaker on, and the battery selector switch in the "both" position. I don't understand why they would have gone dead while attached to shore power. Shouldn't they be...