I'm looking for some more of you gear heads to validate my train of thought on this frustrating issue I've been having. I'm pretty sure I've narrowed the issue down to an intermittent regulator failure. I've got a 98 evo that's popping batteries and bulbs. i checked the charging system per Dr H's sticky and everything came back within specs. Stator not grounded, output good. Cleaned all of my grounds and checked voltage after the regulator. Voltage after regulator was 13.5-14v depending on RPM. Checked diodes on regulator and they were fine. Riding home from work one day the ol' girl coughed a bit acted like the ignition wasn't igniting and then I had no electrical power to anything on the bike and she died. I pushed the bike home since I was only a few blocks away, down some residential streets. Got it home checked the battery and voltage was 10.5 dropping to 6 when trying to start. Took the battery to the local parts store for them to test it and it came back after charge as a bad battery with 0 CCA and wouldn't fully charge. Replaced battery, checked charging system and decided my old battery had just failed since the charging system checked fine.
About 2 weeks of good riding go by with no issues. I had to leave for about 6 weeks and left her on the trickle charger as well as setting her up to be stored. I came home, gave her the tune up treatment with new fluids, plugs and a good checking including the charging system. On the way home from work she sputters and dies again this time blowing all the bulbs except the dash. Headlight, tailight, running lights, and turns all were fried. Got her home and battery was testing bad again. Replaced everything and went to extensively testing the entire electrical system. No odd results except a slightly high resistance to ground on the ground wire of a rear turn signal. Sorted the ground out and checked the charging system. Took her for a ride around the block a few times and checked the charging system hot. Everything tested good. Needless to say I lost another battery, this time it was a lithium ion battery that looked more like a twisted pile of plastic after it smoked to the point I dumped a ten pound extinguisher on the harness and called the local FD because the battery wouldn't quit smoking. After going through a bunch of bulbs and a few batteries I can only imagine the regulator is failing after it gets "hot enough." I'm guessing I wasn't able to duplicate the problem by going around the block and this really is an intermittent voltage regulator failure allowing excessive voltage to overcharge the battery and spike the electrical enough to blow elements in the bulbs before the circuit breakers trip. When the battery burned, nothing else burned. No wires, no insulation, and nothing else besides the battery and bulbs were affected. Sorry for the long post but any help would be greatly appreciated.

 

When I have seen similar in an auto it's been a positive cable rubbed through some where. It can come and go according to where the short (rubbed through) is located.

I think cking all the cables for this condition would be a good Idea.

"When the battery burned, nothing else burned. No wires, no insulation, and nothing else besides the battery and bulbs were affected."

A battery can short out internally but it's rare in my experience.

Hard to imagine the cables don't show some signs of being hot.

Good luck WP

 

Thank you for the input WP50. I did check all of the wires in the main harness as well as the sub harnesses to the bars, signals, etc... I was thinking the same thing, that it was an intermittent short. I tested all the wires while they were in the bike with my multimeter, did the whole shake the harness routine and couldn't find any issues so I took the connectors off the wires and pulled the main harness out of the frame. I visually checked each individual wire from beginning to end and found no issues. I was hoping I could find a simple fix and get back to riding without having to worry about electrical fires. As you said, batteries internally shorting are pretty rare and I highly doubt it's happened three times to me. The only common denominator is that all three batteries were in my bike. It's gotta be something I'm overlooking or something failing and I can't duplicate it while I'm testing. I'm going to keep after it and keep y'all posted.

 

Just thought I'd add too that I thought it was extremely weird to have no burned insulation, no connectors looking burned, or anything even remotely showing something got hotter than normal. The only items affected as far as looking burned were the elements in the bulbs and the battery. Even the battery cables that were connected to the battery while it was smoking, look and test out on the multimeter just fine. I figured I'd be looking at replacing a lot more things than what is apparent right now. I'm out of town at the moment but plan on going back through the harness and sub harnesses again when I get home as a precaution.

 

Yeah, I'm going with an intermittent bad regulator. All the bulbs blowing out is the clue. I would replace that, put a new battery in, check the voltage at the battery and call it good.

I bought a battery on Amazon. It was cheap (for a HD battery) and is working out fine. It was $75. YTX24HL-BS Scorpion sealed AGM from Blue Grass Batteries & Electronics.

 

Paragraphs are your friend.
A large block of text is very hard to follow.

 

Thank you Dr.Hess for the input. I was leaning towards that already and your expert input definitely makes me feel better about dropping the money on a tight budget.

Texashillcountry I will definitely try to break up large blocks of text in the future, thanks for the advice. I looked back at my post and definitely agree with you.

I'll keep y'all updated on the solution so others who have a similar problem can reference my experiences with this.

 

For sure the regulator. Excessive voltage will pop the bulbs.

 

This is a key factor which it certainly sounds that you understand it. Good for you.

Seems a good regulator and a cheap battery is in order. WP

 

Sounds like the regulator is not regulating or rectifying. It is probably intermittant, but it sounds like it is dumping raw AC through the system (instead of being smooth DC regulated at about 13.75 volts)...YD