intermittent "Low Voltage"

[JHardwick]

A couple of days ago I stopped in Ames, Ia to pick up a horse. When I got back in my truck and headed down the road, I got a "check gages" and zero voltage on my gage. So I drove on to Des Moines and bought an alternator, problem solved!?



The next morning, I woke up in Mi and started my truck before I checked on the horses. Again, "check gages" and zero voltage??? So, I shut it down and refired it twice ... ..... viola 14 volts!!



So the next night in eastern Pa, I stop to sleep a few hours and I decided to leave it running. However, I woke up to "zero voltage", and when I pop the hood, a steaming battery !?!



Being a couple hours from my next stop, I decided to shut everything off and make a run for it. Wouldn't you know, an hour up the road it started charging again after hitting the clutch and shuttng it down, then bumping it



I have an inverter for my laptop, and a series of LED's from 11v - 14v on my aftermarket 3-way DC power outlet, so I know it's not a faulty gage.



Would you suspect a battery?

 

[steved]

However, I woke up to "zero voltage", and when I pop the hood, a steaming battery !?!



Would you suspect a battery?

If it was one battery steaming, then I would suspect a direct short in that battery.



I would replace the batteries if they haven't been replaced in a while...

 

[JHardwick]

Ya, it was only the passenger side battery. Neither are very old, but I'll buy one at least before I leave upstate NY.

 

[GaryOwen]

I had a passenger side battery over heat. I disconnected the battery and ran on just one for a few days. Wasn't any problem since the weather was warm. Be sure to wash the area around the battery good to prevent corrosion.

 

[JHardwick]

LOL Gary, I JUST unhooked the passenger side battery, I decided that I could easily get home that way.

 

[JHardwick]

okay, well, now what?

I unhooked the passenger side battery and made it home without incident.

A couple days after I got home, I took the passenger side battery to AutoZone where it tested good. So I argued a little about and intermittent short and got a new one, all is well right?

Wrong.

I put the new battery in and started the truck to idle for 5 maybe 10 minutes and called it good.

Today, we load up a couple horses to go riding and bang, check gages!! Again the passenger side battery was boiling over like before.

So this time I unhooked the driver side battery and we went about our way. So far everything is fine operating on the opposite side battery ... ... ... ... ... so why am I okay on one battery and not 2? Did I replace the wrong battery, or is it the battery at all? I already replaced the alternator in Iowa, so what gives?

So, why

 

[MMeier]

Sounds like you have another bad battery. I've had them bad from the day I bought them before. I'd look everything over good and replace both as a pair myself.

 

[BHanna]

Sounds like a short but may or may not be in the battery. I'd start with a good check of the wiring before throwing more parts at it. You may find some scorch marks where it's happening. Sounds like a lot of amperage if the battery's boiling.

 

[Skydiver]

JHardwick, As I always tell people, "Test the tester" meaning your dash guage could be wrong.

This is a serious electrical problem. A boiling battery means heat and heat could lead to fire. Sounds like the voltage regulator is either allowing all or nothing. Get a good volt meter and proceed.

Try disconnecting the invertor next time this happens.

 

[HBarlow]

Skydiver's advice is good but the fact of a smoking battery says the gauge is right.

I would start over with a pair of matched good quality batteries. I think you'll ultimately find the problem caused by a bad battery causing the other to be overcharged. I think your ECM/PCM contains the voltage regulator and circuit breakers and fuses would almost certainly trip or blow to elimininate shorted wires or devices.

 

[Pawpaw]

A couple of months ago, I noticed my passenger-side factory original battery was showing signs of overheating.



I took it as a sign that one or both of them were dying, and replaced them both with Optima yellow tops. Life is good.



Bob

 

[steved]

Did you happen to have the supposed "good" battery tested??



Don't I remember also about a bad battery temp sensor causing this?? Causes the alternator to overcharge?



The simple fact that both batteries are directly linked together indicates one of them is bad.



Don't rule out checking all the grounds... there are two to the block and about five to the firewall. I found mine with questionable connections and pulled/cleaned/reconnected them... made the truck idle smoother.

 

[jelag]

From 30 years ago, I can remember 4 very important tests on a battery..... one or more are often overlooked by most testers... . all must be done to qualify a battery as being good... .

1 - cell hydrometer test... . giving you the actual specific gravity of each cell... . no more than +- about 10 points... . on a temperature compensating tester... .

2 - Test the battery with a temperature compensated cell tester... if the cells are all the same and it passes this test do a load test at 3 times the AHR (amp hour rate) or 1/2 the CCA (cold cranking amps)

3 - 3 min on charge test. . to test if the battery has too much resistance to be charged... or cell voltage test when on a load... . Put a a 40 amp load on the battery or charge the battery at 40 amps... do not change the load once the test is started... . check each cell voltage with a digital voltmeter using probes designed for this... or a set of nails you can throw away... head of the nail into the cell, don't touch the plates... cell voltage needs to be the same across the battery... . +- . 2 volt..... the load test is used for a fully charged battery, the on charge test is for batteries that fail a load test... .

4 - if your using the on charge test at 40 amps... . at the end of 3 minutes without changing the charging level the battery charger needs to be below 15. 7 volts... if its higher than this... the battery will never take a charge from the vehicle... .

All known battery problems will show up with these 3 simple tests... mind you it takes a technician who understand batteries and these tests... I used to do this whole thing in under 3-5 minutes and now it takes me often 5-7 minutes because I have to get the lid off the sealed batteries... . of course if the battery fluid is below the cells and you can't see it... stop, the battery is toast...

SAE used to call this the 3-minute battery test... . it was used by all manufactures for testing for warranty... . it still holds true today... with the fancy stuff in a battery except the 15. 7 volts changes to 16. 5 volts on high end batteries with a lot of anomony (chemical in plate material) I might have it spelled wrong. .

Hope this helps...

 

[Skydiver]

Good report jelag.

One other safety tip. The steam (gas) from a boiling battery will EXPLODE.

In 1980 my Dad was blinded for 6 months after he stopped to help a stranded motorest. Their battery was dead and all he had for light to see the electrolite level was a butane lighter. BOOM. The person with Dad lead him to a nearby house and the man who came to the door thought Dad had been in a knife fight. Allmost denied him the much needed water to flush his eyes.

 

[JHardwick]

I have no clue. Both batteries test good, all grounds are secure and I can find no evidence off wire chaffing or shorting out.



I can run on the passenger side battery. I can run on the driver side battery. But I cannot run on both batteries#@$%!