Weird battery problem...

[crw]

So, a week ago, the battery went out in my Suburban. I have a diagnostic tester, and it showed it to be unable to charge. The battery was quite old, about 8 years on a 5 year battery, so I just replaced it.

Then, five days later, the new battery is dead. Dead as a doornail. It won't charge at all. I have two chargers and they neither work. I took the new battery out of the vehicle, and I get the same result.

So, I don't know... perhaps it's the alternator. But is this normal to have a new battery that dies from a bad alternator, and it's unable to be revived with a charge? At around $100 per battery, this is not something you want to see. It's a Wal-Mart MAXX brand, and I'll try to get a free replacement... I'm not sure how well that will go.

 

[Corvette Owner]

Yes it is normal. You should check out the alternator, a lot of auto stores will do it for free.

Or you could check the voltage at the battery while car is running. It should be 13.5 volts or higher, if not the alternator is toast.

If you have a bad alternator, usually the battery light will come on.

 

[45ACP]

A volt tester can determine if the alternator is charging.

A vehicle can drive off the battery until it fully discharges.

You may be able to slow-charge that battery back to life, if you charge it right away. Its called "cycling" and a few times wont hurt it. Good for it, actually...

I have experience driving no alternator vehicles to work with two spare batteries, including charging the vehicle prior to going to work. And just my luck? .. the 20 mile drive home is at 4AM so.. headlights needed. Not anymore.

 

[friendly_jacek]

if battery is zero volts, most chargers will not charge. Put the dead one in parallel with a good one and then charge.

 

[The_Eric]

Battery chargers won't charge batteries that are lower than a certain voltage. The trick is to hook a up a known good battery to the dead one via jumper cables, then throw the battery charger on it.

As for the truck, check the charging system and use the multi meter to check for current draw. More than 50-80 milliamps is too much.

 

[45ACP]

Originally Posted By: The_Eric
Battery chargers won't charge batteries that are lower than a certain voltage. The trick is to hook a up a known good battery to the dead one via jumper cables, then throw the battery charger on it.

As for the truck, check the charging system and use the multi meter to check for current draw. More than 50-80 milliamps is too much.


What about good old fashioned manual chargers on the lowest (2 Amp) setting? Leave it sit for "a day?" No?

I once had a 1.5V charger that did not work and sparked and blew up when i plugged it in and connected to battery.. and i have never owned a charger slower than 2 Amps, therefore.

 

[wkcars]

Alternator problem or might have some electrical problem with something that is draining the battery.

 

[crw]

Wow, good ideas on the charging. You may have saved Wal-Mart a battery. I'll try leaving it on my old charger.

This happened while I was out of town. The battery was dead for three days....

 

[eljefino]

Sometimes totally dead batteries, if you let them sit disconnected, will eventually come back to a tiny charge which might make a smart charger happy. Give them a little shake and wait. The 2 amp dumb charger suggestion is a good one as is the jumper cable one.

 

[45ACP]

Originally Posted By: eljefino
Sometimes totally dead batteries, if you let them sit disconnected, will eventually come back to a tiny charge which might make a smart charger happy. Give them a little shake and wait. The 2 amp dumb charger suggestion is a good one as is the jumper cable one.


+1

And i always have felt that that little tiny bit of life, you are right that just "comes back" if its left disconnected.. if slow-charged all the way back up to full.. can save the battery.

Sitting totally discharged for 3 days should be ok. Its when it gets into months and years that the battery loses capacity, and dies.

 

[TFB1]

Wal-Mart would likely replace it if you took it in fully charged and said it was bad, dead will not be a issue...

Like already mentioned, if alternator doesn't produce at LEAST 13.5v when engine is running it isn't charging... In cool/cold weather, with heater blower and headlights on, voltage should be more like 14v to 14.4v if it's charging properly... Charge is tapered back in hot weather to lessen battery boil off...

 

[oilstudent24]

In addition to the alternator test, I would also check and make sure the battery is newish. I have seen some batteries at a big box store. The battery I needed was 7 months old still on the shelf. If you drive short distances an old (new) battery may not have time to fully charge. Not saying you don't have other issues with your charging system but also something to think about.

 

[JimPghPA]

After you charge the battery, when you put it in the vehicle use an amp meter to see how much current the vehicle pulls when the engine is off.

A battery has about 50 Amper Hours of charge. So if a vehicle has a problem and is causing a drain of 1/3 of an amp the battery will be completely drained of charge in 150 hours (about 6 days). It is simple math. So if you have a constant drain because of something on the electric system of the vehicle, you can figure out how many hours it would take to make a total drain of 50 Amper Hours.

It use to be that if you jump started a vehicle with the good vehicles engine running there was a chance that a diode on the alternator would be damaged and leak. That would cause a constant drain that would kill a battery in a few days.

Also if the alternator is charging to too high of a voltage (over 14 Volts) it will cook a battery and kill it. Usually you will smell the acid boiling off if this is going on.

 

[Donald]

I have an older dumb charger I use sometimes to give the battery some charge, then a smart charger to finish the job. I have also connected a dead battery to a good battery and let it sit that way for a few hours.

 

[jim302]

Once you get the battery charged or replaced, the charging system should definitely be checked, as well as the parasitic drain.

Although rare, it is possible to get a battery that dies from a bad cell after a few days, weeks, or months. What does a voltmeter show when hooked up to the battery terminals with no load, engine off?

Even a completely discharged battery should have about 11.9V (this varies by temperature... a colder battery will read several tenths of a volt lower). If you're getting something like 10.5V then the battery has a bad cell or some shorted cells.

 

[JHZR2]

The checkout info is good, and I'd be quick to try to get the battery swapped if truly at 0v, as likely it will be un-testable and exchanged.

I had a bad alternator only once. It put out fine voltage, and if the car was jumped, it would run and even charge the battery a bit.

But turn off the car and the battery would go flat.

Turned out that the alternator had a bad diode in it, so it would discharge the battery when off. I don't recall that I had a light come on or anything! The charge circuit apparently was fine!

 

[crw]

Good news... my old charger on 2 amp mode seems to have revived the battery! I just switched it over to the new charger and it shows 60% and climbing.

The thing about the old charger... I could stare at that display for three days and not understand what it is trying to say. Anyway... I'm glad I kept it. I keep it for my tractor with a 6V system. Looks like I need to keep it forever.

Tomorrow I'll take the alternator out and have it tested. This site is great! Thanks.

 

[ltslimjim]

^Success FTW!

BITOG hits another HR!

My old 'meh' Stratus coughed up a red battery indicator/warning(charging system flagged) to let me know the alternator was going bad before it actually went out(I was beginning to hear some alternator chirping).

 

[mechtech2]

Low batteries can puke an alternator - or at lest hasten their demise.
Many alt warranties are void if the battery is not good.

 

[oppirs]

Originally Posted By: crw
Tomorrow I'll take the alternator out and have it tested. This site is great! Thanks.


I've dealt with dead new batteries on 2 GMC's, 1 Suburban. 2000 -2004. Takes about 3-5 days to drain the battery, DEAD, if not run. It's was a 2.4 amp draw from the radio circuit.

Keys out, pull radio fuse, test for draw. Fix was to buy aftermaket radios and cancel/remove OnStar. Or pull fuse until your ready to use the truck. If alt tests out good, hoped that helped. Good luck!