I have a Victron multi plus. One day found all my batteries dead (they were 10 years old) so I replaced them. The charger still showed low battery. I had installed a shutoff so the inverter wouldn’t turn on while working on the 120 volt system. The switch had failed, come apart. Replaced the switch and everything is back to normal.
You should have a disconnect also for safety’s sake. Just an option.
Linus
Sumocean