[Lee]

Hi,

Do you own a Multi-meter?

Usually a boiling battery is a result of being over charged. If you have a Multi-meter, reconnect the Battery Disconnect, plug the Shore power cord into an AC outlet and measure the voltage at the battery. If you get over 13.8vDC then the battery is being over charged. The charger(Inverter) is causing the boiling and needs to be addressed.

Also, as Face down suggested first top off the battery water level with Distilled water.

Lee