Anyone have an overcharging alternator fry a battery?

[Johnny Mac]

Hey all! Had an odd occurance today, and wanted to see if anyone one had any words of wisdom.

Many of you know I have a 600hp+ smallblock, that I bracket race, and occasionally street drive on e85.
Here's what happened today.

Going Down the road, 1 mile into a maybe 7 mile drive, I start hearing a weird whistle/jingle.

I was JUST under the hood, and honestly wondered if I left a wrench on top of the radiator or something.

About the same time engine starts coming to temp, so I flick the fan on. Seemed to come to temp faster than normal, but it was 85 degrees. On e85, I rarely even use the fan, so thought that was weird.

So I glance at the voltmeter, and the sun is blaring, but it looked like 17+. (Digital and hard to see in direct sun)

Long story short, when I stop, I source the jingle to the alternator, and it's obviously overcharging for some reason. Still spins smooth by hand, so not sure if bearing is bad or what.

Pull alt belt, no noise. I can hand spin it and reproduce noise.

Battery however is at 5V, won't even run the fuel pump.

Anyways, title question....think my 17v overcharge for 5 miles killed my battery?

Probably a dumb obvious question.

With a completely fried battery, would the overcharging alt mess with my elec water pump and fans and cause it to run hotter? Ironically, it did have a small coolant leak out the petcock on the radiator, so it was hotter than normal, but not above 195 on the gauge. I snugged it and seemed to stop.

Seems I'm starting with an alternator, and battery.

@RustyRatRod any thoughts? Any other faba friends have thoughts?



 

 

[RustyRatRod]

I'm not an electrical genius by any stretch, but If I had to "guess" it would be that the battery was bad causing the charging system to max out. Usually, the lower a battery "gets" the more the alternator will charge in an effort to keep up. The jingle simply could be "something" inside the alternator that did not agree with putting out 17 plus volts. But of course, I'm sure I'm wrong. LOL

 

[toolmanmike]

Yep. I had replaced my old point style regulator on my 66 with a new style electronic one. The screws didn't tighten well enough into the firewall (poor ground) and I fried the battery and blew out some bulbs. It boiled the battery all over the driver's valve cover. It was pretty ugly.

 

[Johnny Mac]

Yep. I had replaced my old point style regulator on my 66 with a new style electronic one. The screws didn't tighten well enough into the firewall and I fried the battery and blew out some bulbs. It boiled the battery all over the driver's valve cover. It was pretty ugly.

Yuck!
I should point out its a 1 wire chrysler converted alt. 110 I believe. Probably 5 years old.

 

[Johnny Mac]

I'm not an electrical genius by any stretch, but If I had to "guess" it would be that the battery was bad causing the charging system to max out. Usually, the lower a battery "gets" the more the alternator will charge in an effort to keep up. The jingle simply could be "something" inside the alternator that did not agree with putting out 17 plus volts. But of course, I'm sure I'm wrong. LOL

I'm on the same train for sure lol.

 

[rumblefish360]

My only experience with this is once the regulator went bad and was stuck on charge. The gauge would let every time the car ran. The battery swelled fat and boiled all the liquid out dry. No other electrical items in the car were harmed.

I first replaced the battery since it was burnt toast.
The regulator was next since it was cheaper than an Alternator. Problem fixed and lucky for my young & broke wallet.

 

[Frodee]

Had a problem in that same thing 2 weeks ago, went to start my scamp and battery was dead so jumped it and drove down the road and noticed after driving 50 miles that my volt meter was reading 16 volts.
Checked with a portable volt meter and battery with the car shut off was reading 13.58 volts . Started the car and checked again and 16 volts into the battery.
1 wire Alt. as well still waiting for the repair guy to check it out.

 

[CFD244]

I had an old Reliant go into overcharge due to a bad regulator. Lots of the electrolyte had evaporated, and the plates were dry on top. Replaced the regulator, topped off the battery with distilled water, and got another 5 years out of the battery with no other damage.

 

[Mattax]

All we know is the alternator was producing power at 17 Volts (or maybe more).
The battery would have attempted to overcharge IF it saw that 17 Volts at its connections.
An ammeter would have shown the charge rate, but I don't think it matters at this point.

If the battery is at 5 Volts I wouldn't even bother load testing. I'm not sure it can be brought back regardless of whether it was caused by the alternator running at 17 Volts or some internal failure of its own. Some other guys here have more battery experience and knowledge.
Fix the regulation and probably best plan on a new battery.

 

[Oldmanmopar]

Your Voltage regulator in the 1 wire alternator is bad and didn't control the voltage output. Probably something fell off inside. Replace the alternator and try to recharge the battery.

 

[Demonracer]

Just be very careful if it's over charging, the battery it could explode. This happened to me on the way to a car show many years back, it took forever to finally repair the damage from the battery acid.

 

[Dana67Dart]

About the same time engine starts coming to temp, so I flick the fan on. Seemed to come to temp faster than normal, but it was 85 degrees. On e85, I rarely even use the fan, so thought that was weird

If the charging system was faulty (for what ever reason) you might not have had electric fans when you turned the switch.

and the sun is blaring, but it looked like 17+. (Digital and hard to see in direct sun)

17 v will boil the water out of the battery. And is hard on other 12v electrical components.

Pull alt belt, no noise.

Narrows it down to alternator

I can hand spin it and reproduce noise.

Confirms there is a problem in the alternator.
I would disassemble the alt a d see if there is anything obviously wrong

Anyways, title question....think my 17v overcharge for 5 miles killed my battery

May have boiled the water out so check that in the battery. Then put battery on a trickle charger. I would pull the battery out of the car and do the charging away from anything that could get damaged if the battery explodes.

With a completely fried battery, would the overcharging alt mess with my elec water pump and fans and cause it to run hotter

As noted before a shorted battery will make the alt try to charge at max charge. BUT I am not sure if it would go to 17v

In my experience a really bad battery will keep the voltage lower not higher.

The VR in the alt ( somewhere it was stated tyou have a 1 wire alt) should regulate the voltage to keep things safe. So I'm not sure the alt fried the bat or the bat fried the alt.

But based on what you have said I'm leaning on alt had a problem and over charged the battery causing the cells to go dry.

 

[Mike69cuda]

How old is your battery? Odd things can happen when your battery goes bad. That is the easiest thing to change. I would start there. Check the voltage after & see if it still overcharges.

 

[Johnny Mac]

How old is your battery? Odd things can happen when your battery goes bad. That is the easiest thing to change. I would start there. Check the voltage after & see if it still overcharges.

About 4 years old. It won't even trickle charge above 4-5 volts.

No visible water in trunk (where battery was until I pulled it this morning)

The audible noise from the alternator, and the fact it was super hot when touch kind of tell me it was the culprit in this one, and the casualty was unfortunately the less than new battery.

Could have been worst. Guess I'm lucky it didn't melt down

 

[67Dart273]

It's either the VR or a short of some kind is causing the rotor to "full field." Depending on how it is wired, it could be a short IN the rotor. In any case START by repairing or replacing the alternator. Go from there. As the battery has been boiled it is likely bad.

Nothing to do with this here problem, I do NOT like "one wire" sysems, because they require a vastly oversize charge wire.

 

[volaredon]

Had this happen twice over the 19 years I owned my wrangler. About 5-6 years apart. I was Driving along in town and started smelling what I thought was hot battery acid. Look down and saw the voltmeter pegged on 19. I got where I was going, popped the hood and pulled the caps on the battery. Looked stone empty both times. I replaced the battery both times and all was good. Never had to replace the alternator on that thing in over 200k miles

 

[pishta]

you could pop the vent covers and test for continuity between the + and - plates in the wells. It sounds like your battery may be shorted. you could also start car and remove battery lead but if its full boogie 17V then it may pop some bulbs. Id take the alternator and bench test it first before I put it back onto a fresh battery.

 

[MOPAROFFICIAL]

Hey all! Had an odd occurance today, and wanted to see if anyone one had any words of wisdom.

Many of you know I have a 600hp+ smallblock, that I bracket race, and occasionally street drive on e85.
Here's what happened today.

Going Down the road, 1 mile into a maybe 7 mile drive, I start hearing a weird whistle/jingle.

I was JUST under the hood, and honestly wondered if I left a wrench on top of the radiator or something.

About the same time engine starts coming to temp, so I flick the fan on. Seemed to come to temp faster than normal, but it was 85 degrees. On e85, I rarely even use the fan, so thought that was weird.

So I glance at the voltmeter, and the sun is blaring, but it looked like 17+. (Digital and hard to see in direct sun)

Long story short, when I stop, I source the jingle to the alternator, and it's obviously overcharging for some reason. Still spins smooth by hand, so not sure if bearing is bad or what.

Pull alt belt, no noise. I can hand spin it and reproduce noise.

Battery however is at 5V, won't even run the fuel pump.

Anyways, title question....think my 17v overcharge for 5 miles killed my battery?

Probably a dumb obvious question.

With a completely fried battery, would the overcharging alt mess with my elec water pump and fans and cause it to run hotter? Ironically, it did have a small coolant leak out the petcock on the radiator, so it was hotter than normal, but not above 195 on the gauge. I snugged it and seemed to stop.

Seems I'm starting with an alternator, and battery.

@RustyRatRod any thoughts? Any other faba friends have thoughts?



 

You provide engines for people surely you can figure this out and run the basic tests, load test, short test on alt.. let us know what you find.

 

[Johnny Mac]

You provide engines for people surely you can figure this out and run the basic tests, load test, short test on alt.. let us know what you find.

Agree 100%, just talking out loud. I did wonder how many others have seen it. I've never killed a battery before in this manner (literally while driving). first time for everything!

 

[MOPAROFFICIAL]

Agree 100%, just talking out loud. I did wonder how many others have seen it. I've never killed a battery before in this manner (literally while driving). first time for everything!

If it had a computer it would be more obvious if the battery was bad. Been known to make sensors go wild.

 

[Mattax]

Take this a step further. Can a battery failure cause the system to run at 17 Volts?
Maybe there is a way on some systems, but I can't think of way for the battery to cause that.

A battery failure can result in high (or low) recharging rates, but that won't effect the voltage regulation.

 

[Johnny Mac]

Take this a step further. Can a battery failure cause the system to run at 17 Volts?
Maybe there is a way on some systems, but I can't think of way for the battery to cause that.

A battery failure can result in high (or low) recharging rates, but that won't effect the voltage regulation.

my mind went there too initially, Not sure. I may not find the chicken or the egg on this one. It obviously needs both at this point. always something

 

[67Dart273]

Take this a step further. Can a battery failure cause the system to run at 17 Volts?
Maybe there is a way on some systems, but I can't think of way for the battery to cause that.

A battery failure can result in high (or low) recharging rates, but that won't effect the voltage regulation.

I don't know how. I think this is right at the alternator and what's inside.

 

[oldkimmer]

I had ad many 70s dodge trucks where the wires on the alt gauge came loose and they would over charge 15-18 volts. Other times it was a broken wired at/near the regulator plug. Mim