# Bad Battery. Ruining Alternator?



## Last (Jul 27, 2004)

I've had my GTO for a couple of days & when I first brought it home I put it on a battery charger because it had been sitting on the dealers lot for so long. The 'Green Eye' indicator on the battery is black & I can not get the battery to fully charge. I no doubt will have the battery replaced soon.

However while my battery will start the car I have bad feelings about driving it without the ability to keep a charge. This can not be good for the Alternator?

Any thoughts on driving the car till I can get it in or should I let it sit until I have the battery replaced?

Thanks for any & all replies.

Last :seeya


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## rock421 (Aug 7, 2004)

The "green eye" is not always the best indicator of battery condition. The new replacement Delco batteries don't even have the eye. If the car is starting OK and you arent getting any SES light, then don't sweat it. Once you have started the car, the battery is doing nothing but being recharged. The alternator is what supplies the vehicle with current and the battery is just giong along for the ride.
If the car won't start after a few days of sitting, then you should have the battery replaced.


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## Last (Jul 27, 2004)

I agree that the battery is doing nothing for the car once you've started it but won't the alternator have to work harder to try to charge a battery that won't go to a full charge?

Thanks for your reply.

Last :seeya

btw: no SES light.


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## rock421 (Aug 7, 2004)

I don't believe so. The battery just won't take any more charge.


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## Napalm (Dec 19, 2004)

I noticed the eye on my battery is black also and that the battery is not sealed like a maintenance free battery should be. My next battery will be an Optima or an Interstate.

Also when the engine is at idle most cars do not produce enough power for the electrical load, thus you do run off you battery at idle. Also if your battery was bad and causing a problem with your alternator then the computer would give an indication. OBDII systems are nice.


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## rock421 (Aug 7, 2004)

> Also when the engine is at idle most cars do not produce enough power for the electrical load, thus you do run off you battery at idle.



Get yourself a hand held volt meter. Start your car and turn on your headlights, A/C, stereo, and whatever else you can think of. Check the battery voltage when the car is at idle. Turn off the ignition only and check your battery voltage again. 
The car manufacturures are not going to give you a vehicle that would deplete itself if you were to get stuck in hours of traffic with headlights, heater, windshield wipers etc., all running at the same time. 
I run a late model 100 amp alternator on my 65' with an underdrive crank pulley and a larger diameter alternator pulley. Even with the alt. turning slower (at idle) than the factory intended, the car will still idle at 14.4 volts.

Just my .02 volts worth,

Brian


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## Last (Jul 27, 2004)

rock421 said:


> Get yourself a hand held volt meter. Start your car and turn on your headlights, A/C, stereo, and whatever else you can think of. Check the battery voltage when the car is at idle. Turn off the ignition only and check your battery voltage again.
> Brian


Hey, thanks for the instructions! I've got a volt meter on the way from Harbor Freight.

What a great forum!

Thanks again.

Last :seeya:


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