After connecting our boat to240v landline and leaving the victron charging for 48 hours our leisure batteries have overcharged and one even blew the top off. Recently purchased the boat so thought the set up was the same as our previous boat in that we could just leave the charger to trickle feed the batteries through the winter lay up period
I assume the charger is a Victron one? I have seen this happen before and it usually down to a faulty battery. There are of course many other possbilities, for example the wrong settings in the charger for the battery type, poor wiring on the boat. We have lots of instalations using Victron chargers none of which cause any problems. I would start with changing all the batteries then mnoitoring the voltages when the charger is switched on and for several hours after that.
