[ctrlz]

Originally Posted by avalonandl

Yup we needed not one but TWO posts with mostly about nothing to do with the charging system which can very succinctly be stated as charging on demand.

Thanks for the compliment.
Since this comes up often, I thought some members might want the details.

[Need4Camaro]

Just wondering, does this prolong alternator life? and does it hurt battery life?

[ctrlz]

Originally Posted by Need4Camaro

Just wondering, does this prolong alternator life? and does it hurt battery life?

It's mainly a fuel economy thing. If you disconnect the stator fields in the alternator (which GM incorrectly calls a generator) the rotor spins freely. Less work for the engine. This business of moving metal through magnetic fields is how a lot of home exercise equipment creates resistance.

The charging system has many sophisticated features which basically match load to demand, and also can compensate for battery problems.

[dmcmahan60]

Reviving this thread because my car has never charged over 14 volts before. Battery was replaced over 2 years ago and iis driven everyday. When I first start the car it is under 14 volts but about 5 minutes it is over 14 volts per the guauge. about half way between 14 and the first big line. just trying to figure out if it is the alternator on the way out or the battery? It does not show any signs of slow cranking. started doing this a few days ago after it sat a few days without being driven only a few miles every other day. Thanks for the help.

[arpad_m]

Originally Posted by dmcmahan60

Reviving this thread because my car has never charged over 14 volts before. Battery was replaced over 2 years ago and iis driven everyday. When I first start the car it is under 14 volts but about 5 minutes it is over 14 volts per the guauge. about half way between 14 and the first big line. just trying to figure out if it is the alternator on the way out or the battery? It does not show any signs of slow cranking. started doing this a few days ago after it sat a few days without being driven only a few miles every other day. Thanks for the help.

Looks normal to me. If you drive the car for a longer time and the displayed voltage drops down to 12.5-12.7, your battery is fully charged and everything is normal. As mentioned in several posts above, the charging voltage will vary, that in itself isn't a problem. Whenever I don't drive the car for a couple days, it takes longer and a higher voltage to recharge the battery.

[dmcmahan60]

Originally Posted by arpad_m

Looks normal to me. If you drive the car for a longer time and the displayed voltage drops down to 12.5-12.7, your battery is fully charged and everything is normal. As mentioned in several posts above, the charging voltage will vary, that in itself isn't a problem. Whenever I don't drive the car for a couple days, it takes longer and a higher voltage to recharge the battery.

I drive 30 miles one way and it never drops down to under 14 volts. Plus you can see the needle or arm on the guage flucuating back and forth between 14 volts and higher. Went ahead an odered a new alternator because I do have 105k miles on the original alternator. Thanks for information.

[Rock-It Man]

Originally Posted by dmcmahan60

I drive 30 miles one way and it never drops down to under 14 volts. Plus you can see the needle or arm on the guage flucuating back and forth between 14 volts and higher. Went ahead an odered a new alternator because I do have 105k miles on the original alternator. Thanks for information.

The most likely explanations for the charging voltage staying high:

1. You're not driving enough to get the battery to full charge. 30 miles may not be enough if that's the longest you ever drive.

2. Your battery is aging.

It's not at all obvious that anything will change with a new alternator. What exactly wears out in an alternator, other than bearings?

[dmcmahan60]

Update, had the battery tested at 3 different parts stores and all said the battery was bad. Went to Auto Zone where I had purchased the DuraLast Platinum AGM battery and had 8 months left on the 3 year warranty. Installed new battery and right back to charging over 14 volts even after my 30 plus mile commute to work this morning. New alternator will be here from RockAuto tomorrow and will go from there. Thanks and Rock It is is a 30 mile commute 1 way, so a few days of 60 miles a day should have been more than enough. Electronic components go bad when ever they feel like it my friend.

[ctrlz]

Originally Posted by Rock-It Man

It's not at all obvious that anything will change with a new alternator. What exactly wears out in an alternator, other than bearings?

Agree. I think alternators are pretty reliable. I have had more issues with diodes or built-in voltage regulators than the mechanicals.

Autozone is pretty liberal about their battery returns, which is nice. I'm pretty sure the fine print says the warranty is pro-rated, but last two times the kid has given me a new battery, no questions, no charge.

[ember1205]

Originally Posted by dmcmahan60

Update, had the battery tested at 3 different parts stores and all said the battery was bad. Went to Auto Zone where I had purchased the DuraLast Platinum AGM battery and had 8 months left on the 3 year warranty. Installed new battery and right back to charging over 14 volts even after my 30 plus mile commute to work this morning. New alternator will be here from RockAuto tomorrow and will go from there. Thanks and Rock It is is a 30 mile commute 1 way, so a few days of 60 miles a day should have been more than enough. Electronic components go bad when ever they feel like it my friend.

What's the next step if the alternator doesn't change the behavior? I have a suspicion you're diagnosing a modern car using older car symptoms and it isn't going to go the way you're expecting. The gauge in the dash does not represent what I believe you think it does, and does not necessarily indicate a problem.

[dmcmahan60]

I will try and figure it out after the new alternator is in. The guage has never read over 14 volts in the 4 years I have owned the car. Why would it change just like that the next time I drove the car? Just measured it with a multi meter at the points under the hood where you can jump the car if needed and it was 14.7 but when driving will climb a bit higher.

[ctrlz]

My car pops into the 14.7 range every day. It does tend to back off as I near work. But my commute is only 15 min.
i think i will try arpad's idea and put it on the charger every month or so. I just went 6 years on my first battery without ever putting it on a charger, so even that miniscule commute must be enough. i consider 6 years very respectable for battery life.

[dmcmahan60]

Originally Posted by ctrlz

My car pops into the 14.7 range every day. It does tend to back off as I near work. But my commute is only 15 min.
i think i will try arpad's idea and put it on the charger every month or so. I just went 6 years on my first battery without ever putting it on a charger, so even that miniscule commute must be enough. i consider 6 years very respectable for battery life.

Put a new battery in it last night and drove 30 plus miles to work this morning and it never dtopped under 14 volts. I drive it everyday and hey at least I got a new battery out of it and the new alternator will be here tomorrow. Thanks for the input guys and will update tomorrow night.

[ctrlz]

Originally Posted by dmcmahan60

Put a new battery in it last night and drove 30 plus miles to work this morning and it never dropped under 14 volts.

So, yeah, new battery does not necessarily mean fully charged. I put my new battery in last week or so and, even though it started the car, I decided to top it off with a charger. Took about 16 hrs to get to full.

Without being pushy, I would suggest you hold off on installing that alternator and invest in a decent charger. Installing the alternator is much more of a pain than charging the battery and I bet your battery just needs to be topped off. return the alternator and even if you have to pay shipping it will be a wash. As the many charger/tender/battery threads here can attest, your money for a good charger will not be wasted.

Also, I suspect many of your initial problems were due to a crap battery. Bad cell, intermittently bad cell, etc. That's enough to mess with the Camaro's brain.