What is causing my battery to boil over?

Answer by  mechtech74 (692)

Clean cable ends and tighten them, check fluid level is about 3/4 inch from the top of the battery, then test voltage across the battery, car running. Over 14. 6 volts? Your voltage regulator is allowing overcharging. If built into the alternator, you have to replace both. Otherwise, your battery is defective, especially if boilover affects only one or two cells.

Answer by  worker3643 (39)

Check the voltage with the engine off, if over 13v you are overcharging this usually means the voltage regulator if malfuntioning.

Answer by  Michael90 (99)

it is probably time to replace the battery. but it could be that you have too much water in the battery.

Answer by  Riley (765)

Batteries boil over where there is a slight direct short or over=charging. When a battery is over charging it is usually a voltage regulator problem. When there is a slight direct short the power side of the battery and the ground side of the battery are touching each other through a nicked or broken wire causing the problem.