Thank goodness this didn't happen in my boat, but not sure why it happened at all. This fall I noticed that when I started my backhoe the battery
seemed a bit low. It seemed to take a charge pretty well, but eventually, after a couple of days without running it I'd have to put the charger
on it to start the engine
. I assumed I had a small short somewhere in the system but didn't have the time to go looking for it. Finally I hung the battery charger
on it one evening. It started out charging
around 20 amps and after 45 minutes dropped to around 10 or 12 amps. I decided to leave it on over night to top off the battery. Sometime during the night the battery exploded. My wife heard it, but I didn't and she didn't tell me about it until the next evening. I forgot to check the charger in the morning so didn't discover the situation until after work the next day.
OK here's my line of thinking. I believe the battery had an internal short that was causing it to lose charge and when put on the charger, heated up and started venting hydrogen gas. At some point there was a spark that ignited the hydrogen and the battery went blewy. The battery was an 18 month old NAPA battery so I picked up all the pieces cleaned things up with lots of baking soda and brought it all in to NAPA for a warrenty exchange. After a lot of head
scratching they decided the problem had to be my charger and no one at NAPA could imagine how a battery could develop an internal short, and had no idea how an internal short could cause a battery to blow up anyway.
There really are two questions here. The first is, "Is my hypothesis that the problem developed from an internal short likely?" the second is "If not, what type of problem with my battery charger could have caused this to occur?" Actually a third question would be "How could I discover either of these situations ahead of time so I don't blow a hole in the bottom of my boat?"
Thanks in advance for any insight from the "far more experienced than I" who reside on this forum.