Check your battery charging setup if you want to avoid unpleasant surprises is the message in a safety alert issued by Marine Safety Forum. In this case two chargers were at work simultaneously, evaporating electrolyte and leading to an explosion.
As part of his weekly routine, the Engineer was carrying out planned maintenance of emergency generator. When the Engineer started the generator, he heard a loud bang from the battery container.
He stopped the process and investigated the noise which was when he discovered that one of the starter batteries had fragmented with the top of the battery detaching from body.
The battery was safely removed and switched over to hydraulic starting mode.