I have a small Victron charger/battery management/inverter (sorry not got a model number at present, as not on the boat) It charges two banks of 2 x 12 volt batteries, 2 engine, 2 domestic on my boat. 24 volt system. Last week my domestic batteries expanded and overheated dangerously and I had to remove them from the boat at once! They are AGM 200 ah batteries a little less than 3 years old.. The engine starter batteries are fine.
I have ordered two more 180 ah batteries (Varta) to replace them. But I am worried it will happen again. Everyone tells me it is probably because of overcharging - but can my reliable Victron charger do that? Is it capable of overcharging? I thought it was automatic and would sense the charge and stop charging. The boat is 10 years old and has been performing pretty well with no charger problem that I know of. Can anyone help?