Last Saturday I went to start my boat. It sounded as though someone had fired a .38 in the engine compartment. Everything went dead. Inspection showed that one of my batteries had exploded. Acid everywhere along with battery case fragments. Other than having to wash everything down and neutralize with baking soda it blew the connectors off the electric fuel pump. There are three batteries on the port side and getting the shattered one out requires removal of one them by taking out the remains and turning it sideways 90 deg to get over a large muffler. Try that when its going to dump it's acid over one. Stepson helped and now its time to do battle with Interstate Battery and Costco.
So lesson for one and all. Battery 3 years old. Never overcharged or frozen. Well ventilated. No reason for it to explode. Internal short probable cause from manufacturing defect.
Fortunately the hatch was closed and retained the flying acid and parts. When doing ANYTHING with batteries wear eye protection and never connect a battery under load or be near it when you are charging or discharging it.
This was my second such incident over the years. Not as uncommon as you might think.
Be safe out there.
Keith
hot battery temps need lower charging voltage
What kind of batteries, vent caps, etc? Easy for a spark to occur at the posts with high starter draw. Low electrolyte level gives lots of room for an internal explosion. Usually an external explosion will not cause the battery case to blow apart. High charging rates can cause high temperatures boiling off the water in the electrolyte and dropping the level and allowing room for explosive gas.
When an internal short happens, it's not unusual for the battery to blow off the caps and act like old faithful for about 5 minutes.
Pierce
Battery 3 yrs old maintenance free, electrolyte level OK, temp high 40's. Compartment ventilated before explosion. Never fast charged always trickle charged. No ignition sources present. Battery not used for a week. Engine started fine when load transferred to other bank.
Therefore I surmise an internal defect as plates badly distorted and burnt.
Keith
I made the mistake of removing a tractor battery and putting the charger on it over the winter. It exploded also, lucky I was no where around when it happen. Now I use trickle charger or smart charger.
Earlier this year we did a Laborers project with a couple that had a new-to-them Newmar. As we were visiting he told the story.
They had a Newmar very much like this one a year ago. They were Wally-docking and had gone out for dinner. When they came back their coach was missing and there was a large burned area on the parking lot. Wal-Mart was watching for them to come back and told them what happened. Their coach "blew up" and one tire flew about 50' where it burned into the blacktop. Insurance and fire investigators finally determined that one of the batteries exploded.
They don't have pets, so no loss of lives. The coach, though, was thoroughly destroyed. They were able to salvage only a few things. The battery space is directly below the bed, so if this had happened during the night they would have been right on top of it. Wayne is a bit hard of hearing, but he thought that he would have been able to hear the explosion.