It is a GSX-R750 with AGM (absorbent glass mat) battery. The attached pictures show how it has bulged out on all four sides and the top. The charge was 12.9V when I first tested it, but that dropped quickly under load (10 ohm => 1.29V, 220 ohm => 8V). I'm thinking this was severely over-charged, and am grateful that it didn't leak or even explode. What do you guys think? I think traditional "wet" batteries fine for most applications, see no need to waste money on fancy types, but this is and example of how AGM may have been a real blessing!
The back-story: This battery has been in service for a couple of years. About a month ago the charge was down enough for the bike to not crank. I determined that the alternator was OK, but the regulator was bad, so replaced the regulator and all was well until today. I'll put another battery in tomorrow and check things again, but I'm pretty sure I'll find the charging voltage is way high. This is a rather crude charging system, the alt has flying-magnets as a "fixed" field, so out put is always maximum. It could rise quite high as engine rpm increases (12K+ rpm), but the regulator shorts the alt (full current) output "as required" to keep voltage down to desired 12-14V range. Yep, many times the regulator is dumping 300W or more as heat. If anybody is curious, I have a copy of the FSM, thanks to nickb2, with schematics of this poor design. I'll contact the(aftermarket) regulator people tomorrow after I confirm it only lasted about a month.
Wow Bill. Nice pics.
I probably told this story here before. But when a car battery exploded next to me from my knocking out some skid-do clutch springs. I was lucky to still have eyes. I was literally pulling off my clothes with my bare hands.
Since I am not very affluent in battery tech, I just see that battery as being sediment-ed so much, the lead just lay down and no charge will ensue. When that happens, they are literally a walking time bomb. You got lucky Bill. You caught it just in time. In your case. a AGM battery in principle should not sulfate.
I was charging a truck battery, think it was a ranger. So while I was banging the clutch springs out in the vice, the work bench just moved enough to spark. Clamp of that sun charger where nowhere to be found for weeks.
It was careless of me to have a charging battery which I knew was sulfa-ted that close to me.
I see the battery vented in three spots between the + and - on your first picture. Yeah. kinda of makes a guy say HMMM.
You need to really overcharge a AGM for them to explode.