Why Would a Starter Battery Boil?

Question:

We connected new house batteries in the same pattern as the old and our starter battery started to boil. Yikes! Having a gas engine and nearly creating a fire, we think we need some expert advice. What may cause this? We are the little blue/wood boat you were on board last summer in White Rock Bay.

Answer:

It is certainly not normal that your starter battery would start boiling after a swap-out. Boiling batteries is generally an indication of overcharging, not bad wiring.