Battery Help Please!

Thanks in advance for any help you can provide.

My chevy truck has been sitting in the cold weather for over a month now. It has a Die Hard Gold battery that is probably 2 years old. Well, it would not start so I put the charger on it for two hours. The charger said 100% after 2 hours so I tried it and it started right up. The temp was 25 degrees. I let it run about 30 minutes. When I got back in the cab, the headlights were kind of dim and the gauge was at the far left, about 8 volts? So I turned off the ignition and waited 30 seconds. Now it won't turn over.

Not sure what to do now? Thanks for your help!

Brian

Reply to
bml
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Your battery isn't getting a charge. You will need to put it back on the charger.

The brushes on the alternator 'might' have seized up from sitting. I give them a whack with a mallet or chunk of 2x4 to see if suddenly the idle drops down indicated the alternator turned back on.

You could have dirty battery cables.

The fan belt might have dried out so it no longer grabs the alternator pulley. You can hand check that. With a cold off engine, see if you can slip the alternator pulley in the belt. If you can, the alternator won't grab good enough to charge under load.

You should get a multimeter so you can trace the power levels to see if the alternator is actually putting out, but you have a bad connection or not.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >
Reply to
Mike Romain

Time for a new battery. The small drain of the computer/clock, whatever else drained the battery and when it was cold it froze. Replace it, make sure the new one is fully charged and either leave it disconnected until you need the truck OR install a battery tender on it and leave it plugged in. That will keep the battery at full charge and prevent it from freezing. DO NOT try to drive it with that battery since the shorted cell in it will cause the alternator to crank the voltage and amperage up in an attempt to charge the battery and that will damage the alternator and possibly other items as well.

Steve W.

Reply to
Steve W.

I thought idle speed wasn't enough to charge a battery.

Reply to
Jon C

Um.... er.... If I read what he did correctly, he charged the battery so that it (at least) held enough charge to start the truck. Then he ran the engine for 30 minutes, during which time the battery DISCHARGED to the point that the headlamps were dim. With the engine running.

That sounds like a charging system problem to me. Now the battery may be dead as well, but even a dead battery should not show a voltage DECREASE with the engine running over a half hour period.

Reply to
Steve

Back in the days of generators, that was sometimes true (not usually, even then). But since Chrysler introduced the alternator in 1960, alternators have had plenty of output capability to charge a battery at idle, provided you don't also have too many other electrical loads switched on.

Reply to
Steve

How do you define too many? Headlights are, what, 70-100 watts by themselves? 7 or 8 amps?

Reply to
Jon C

DECREASE

A frozen battery will have an internal short. Using the charger on it will give it enough juice to start the engine. Then he left it running. The alternator probably died during that time due to the low voltage and it's attempt to charge the bad battery. Happens a lot in cold climates. It is also the reason why they warn you NOT to use the alternator in a vehicle to charge a dead battery. The regulator overheats and fries.

Reply to
Steve W.

don,t bang or hit anything!!! u can check the charging youself w/ a DMM or remove the ALT. and have a parts store check it for u. The ALT. should be putting out 13 to 15 volts to jump over the 12 volt Batt. voltage. BATT. needs checking as well

-- rusvd

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Reply to
rusvd

Depends on the relative size of the alternator and the electrical loads. But even the original 1960 Chrysler alternator could carry a set of headlamps at idle with a reserve left over for battery charging.

Pretty much ANY car made in the last 30 years should be able to charge the battery at idle unless things like the rear defogger, high-beams, heater with the blower on high fan speed, heated seats, etc. are turned on. Normal engine electrical loads should leave PLENTY left to charge the battery.

Reply to
Steve

Sounds like problem with your charging system. I would inpsect the alternator. Make sure the belt is not broken or slipping. If that looks ok, then pull the alternator and have it checked out.

-------------- Alex

Reply to
Alex Rodriguez

it is oviolsy ur alternator, i dunno y people try and over-diagnose these things. take it to a shop, and they will AVR test ur alternator to verify that that is the problem.

Reply to
newcastlenissan

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