# Variable Alternator Question



## jblackburn (Apr 14, 2012)

It sounds like it. Or it's low from lots of short trip driving

Advance auto parts and autozone will do a load test for you and tell you what kinda health the battery is still in. Then you can replace it under warranty. 


Sent from AutoGuide.com App


----------



## APCruze (Mar 7, 2013)

by chance do you have a amp installed, I know when I installed my amp it seems to stay a about the 13.5 volts.


----------



## spacedout (Dec 7, 2010)

jblackburn said:


> It sounds like it. Or it's low from lots of short trip driving
> 
> Advance auto parts and autozone will do a load test for you and tell you what kinda health the battery is still in. Then you can replace it under warranty.
> Sent from AutoGuide.com App



Ya the car does get one short trip a day(under 5 miles), but also drive another trip that's 30-90miles every day. Weekends usually rack up another 200-400miles in one trip. I'm at 30,000 but if the battery is bad I think I might just buy something else out of pocket. 

Will try to get the battery tested ASAP.


----------



## spacedout (Dec 7, 2010)

APCruze said:


> by chance do you have a amp installed, I know when I installed my amp it seems to stay a about the 13.5 volts.


Nope, my car is completely stock, even has an intact resonator.


----------



## jblackburn (Apr 14, 2012)

spacedout said:


> Ya the car does get one short trip a day(under 5 miles), but also drive another trip that's 30-90miles every day. Weekends usually rack up another 200-400miles in one trip. I'm at 30,000 but if the battery is bad I think I might just buy something else out of pocket.
> 
> Will try to get the battery tested ASAP.


That should be more than enough to keep it charged. May have a dead cell. Don't have a voltmeter lying around at home do you? Anything lower than 12.6-12.8V means it just isn't holding a charge. 

An Interstate or Optima would be at the top of my list. 


Sent from AutoGuide.com App


----------



## spacedout (Dec 7, 2010)

Finally got around to testing the battery(at home), was reading 12.2 volts after sitting 3hours. DIC volt reading also indicated 12.2. Looks like I should go get this thing tested tomorrow. 

Am I mistaken thinking GM removed the volt reading from the DIC mid 2012+ cars?


----------



## obermd (Mar 3, 2012)

The car still shows the alternator voltage. You're thinking the digital temperature readout. You definitely have a battery on its way to the recycling center.


----------



## 2013LT (Jul 3, 2013)

You can't test the battery by hooking up a voltmeter to it. 12.7 volts is totally normal at the battery during idle because the ELD (Electric Load Detector) is telling the car it does not need full power to keep the car running. While your driving the voltage will go to 14V+ because the car needs it to be stable. It won't hurt to test the battery but I assure you it will probably come out A-OK. When you hook up the voltmeter to the terminals on the battery and the car is running your actually checking to make sure the alternator is doing what it's supposed to. So remember, Idle is around 12.7 volts and revving is 14.5 or so. Get in the car and rev it with the voltmeter hooked up and you will notice the ELD will immediately tell the alternator that it needs more power.

The reason your showing 14.x volts on the battery after a drive is because it's holding a residual charge. Turn your lights on for 5-10 seconds and you will see it will immediately drop to 12.x


----------



## spacedout (Dec 7, 2010)

2013LT said:


> The reason your showing 14.x volts on the battery after a drive is because it's holding a residual charge. Turn your lights on for 5-10 seconds and you will see it will immediately drop to 12.x


You misinterpreted what I was asking/saying, My question was more bout the variable output part, since mine does not seem to work like when new. I do understand that testing the battery with the car off at the battery terminals will give the battery voltage and with the engine running the alternator output. 

when new my car would idle at about 12.7-12.9V alternator output and driving rarely ever was at 14V or higher. Now it seems to always be above 13.5V(idle) and around 14.5V on the highway. With the car off my battery reads 12.2V, which is a tad low.


----------



## 2013LT (Jul 3, 2013)

Ahh I'm sorry. I did misunderstand


----------



## spacedout (Dec 7, 2010)

2013LT said:


> Ahh I'm sorry. I did misunderstand


No problem, thanks for trying to be helpful.


----------



## 2013LT (Jul 3, 2013)

But anyway you are right to getting it load tested as 12.2 is a little low, I'll just agree with everyone there haha.


----------



## jblackburn (Apr 14, 2012)

12.2V = dead battery cell and low cranking amps. Time for a new one.


----------



## spacedout (Dec 7, 2010)

obermd said:


> The car still shows the alternator voltage. You're thinking the digital temperature readout. You definitely have a battery on its way to the recycling center.


Thanks, ya I was unsure, glad they all still have it. Think for a second if the cruze had a normal alternator I would have had no indication of the change/weakening of my battery, the volt gauge would have just showed 14.5V all the time when driving. At least with the variable alternator if you notice like I did that it seem to constantly be charging more than usual you might need to check out battery. 

I'm under warranty still but have a hard time putting in the same crappy battery, in the last 15 years every single time I have been stranded in a car was from battery issues(not flat tires). Have been looking around and so far all brands I have checked are 600CCA for a cruze replacement battery, not 438CCA like the factory one. Might be able to leave the car for a couple extra days in the winter with that much more amps.


----------



## spacedout (Dec 7, 2010)

I have had one electrical issue since this winter(when I first noticed the higher charging rate), my radio source resets itself almost every night. I would not attribute this to the battery, however my 2004 cavalier this is exactly how the battery run down protection started to effect things(radio disabled or source rest in the AM).


----------



## 2013LT (Jul 3, 2013)

Personally I'd just replace it under warranty. You may have just gotten a defective battery not sure if others on the forum have had problems.


----------



## jblackburn (Apr 14, 2012)

If a bigger battery will fit the tray, there is absolutely no harm in going with a larger capacity battery.

Some OEM batteries tend to die after a few years; some tend to be very good. Chryslers are on the terrible side (my dad had 3 under warranty in as many years), two Hondas replaced under warranty, and for some reason, the Ford Motorcraft ones have been excellent. 

QC seems to be a problem with many automotive batteries these days. Stay far, far away from the Duralast ones sold at Autozone - they are garbage and I've been through 3. Interstate, Kirkland, DieHard, or Optima would be a good replacement.


----------



## 2013LT (Jul 3, 2013)

Hmm I'm going to add Everstart Maxx from Walmart to the list. It is manufactured by Johnson Controls and they make excellent economical batteries that tend to last a long time. Not only that but you get them at a great price. Do some research on Optima it is overpriced and made by Johnson Controls.


----------



## spacedout (Dec 7, 2010)

2013LT said:


> Personally I'd just replace it under warranty. You may have just gotten a defective battery not sure if others on the forum have had problems.


Ya it would save me $150 but in 1.5 years I would probably be replacing it all over again. There has been quite a few people replacing them in that time frame. I usually only get 3-4 years max out of any battery, so 1.5 out of this doesn't surprise me. 

here are a few of the more recent crappy battery posts....
http://www.cruzetalk.com/forum/25-service-issues/19105-battery-leak-again.html

http://www.cruzetalk.com/forum/10-engine-technical-discussion/14184-dead-battery.html


----------



## spacedout (Dec 7, 2010)

jblackburn said:


> If a bigger battery will fit the tray, there is absolutely no harm in going with a larger capacity battery.


Well if that's the case I see the diesel uses an 800CCA battery and utilizes the entire battery tray, might be a bit of overkill though, LOL. I've had pretty good luck with Interstate in the past, but am somewhat leaning toward the DieHard AGM this time.


----------



## 2013LT (Jul 3, 2013)

That really sucks. My original Honda battery in my civic lasted 7 years. It was made by Johnson Controls. I wonder who makes the Cruzes batteries. Gonna go look at that thread you posted now.


----------



## 2013LT (Jul 3, 2013)

I'm not totally sure about DieHard AGM but Diehard is a Johnson Controls battery. Interstate is made by Johnson Controls as well. There are only two major battery manufacturers that sell in the US and they are Johnson Controls and Exide. JC is better than Exide. They have been gobbling up all the smaller companies throughout the years and besides Odyssey and a few other real small players that's what you get. My recommendation is to get the cheapest JC battery you can find because they all come out of the same factory and are generally just rebranded for sale depending on what store sells them.


----------



## Merc6 (Jun 8, 2013)

My longest lasting batery was 8 years. It was a Optima red top that I paid like $90 new for. Wish they still cost $90 today. Any word on that diesel battery, I might jump on that for winter piece of mind later on down the line. Motorcraft has a few batteries out there with 1100 CA ratings; I had one in my Marauder when the factory one went on me.


----------



## obermd (Mar 3, 2012)

I've only ever had one DieHard battery die early and Sears replaced it under warranty. I also opt for the largest cranking amp battery that will fit in my car when I replace the battery.


----------



## BowtieGuy (Jan 4, 2013)

For the price of the DieHard AGM, you can get an Interstate MTP-47/H5 with 880 CCA(now _thats_ overkill haha).
Interstate Batteries Results Page - Mega-Tron Plus 47/H5 Automotive Battery Six-Year Performance 60Ah RC


----------



## spacedout (Dec 7, 2010)

I replaced my battery 3 days ago after I had 12.1V in the AM before I started and had a slightly hard start. All the aftermarket replacements I looked at were 600CCA, the factory battery is rated at 438CCA. I decided on the Diehard advanced gold Group 47AGM(direct fit).

The day before it was 85degrees, on the 2+ hours I drove the alternator was charging at 14.5V the entire time, even if I shut off everything in the car & idled it was at 13.5V. After I installed new battery before I cranked was at 12.3V, I noticed it was at 14.1V for an hour when driving, then dropped to 12.5-12.9V range like I used to see. This weekend in similar weather even with everything turned on in the car(fog/headlights, stereo, GPS, AC & max fan) it stayed in the 12.5-12.9 range most of the time when driving. The only spike I ever saw was when I got on it for 12 seconds. 

Seems the variable alternator can be a good indicator of possible battery issues, have had 12.6V before starting every AM so far with the new battery and 99% of the time the alternator is now running in a lower output mode(12.5-12.9V).


----------



## Dale_K (Jul 16, 2011)

The Cruze has unusual charging system that attempts to save gas. I doubt the OP has a bad battery. The car monitors battery condition and normally tries to accomplish all the recharging while the car is coasting or slowing down. You can check this yourself by switching the DIC to the voltage page and watch it while you drive. The voltage will go up to 14.5 or higher when you take your foot off the gas and coast. 

If the car detects the battery is getting low on charge for some reason like frequent short trips it will run the alternator to charge it during the entire drive, not just when slowing down. The point is, that it's normal to see the system voltage fluctuate as you drive. There is probably nothing wrong with the OP's car. It's just a high tech way to save gas.


----------



## spacedout (Dec 7, 2010)

My car was always charging at 14.5v or more and I had only slightly over 12V before starting in the AM, since I swapped batteries I never see it above 12.5-12.9V when driving and 12.6-12.7 in the AM before starting and sitting all night. My radio also does not reset sources every AM like it was with the old battery for the last 6 months. 

Sure I understand the alternator will charge at different rates under different situations, but mine was constantly charging at a high rate unlike when my car was new, now its back to normal. I would say that sure does indicate there was an issue with the old battery, for some reason it would not ever fully charge even after hours of driving. I average 50 gallons burned a month in the summer at 37mpg(60+ miles a day), that should be more than enough seat time to charge the battery.


----------



## AutumnCruzeRS (Sep 10, 2012)

Thanks for the info guys. Lately I've noticed the dic voltage being at a constant 15-15.2volts while driving my 50 mile commutes. I thought this was off from what it usually reads. I am still on my oem battery with 104k on the odometer so I'm definitely going to get my battery tested. I'm sure I'm in for a replacement.


----------



## jblackburn (Apr 14, 2012)

AutumnCruzeRS said:


> Thanks for the info guys. Lately I've noticed the dic voltage being at a constant 15-15.2volts while driving my 50 mile commutes. I thought this was off from what it usually reads. I am still on my oem battery with 104k on the odometer so I'm definitely going to get my battery tested. I'm sure I'm in for a replacement.


That was a sign mine was going. The ACD batteries don't have a very long lifespan.


----------



## AutumnCruzeRS (Sep 10, 2012)

Alright went to AZ today and had them load test my battery in the car. Guy said tested ok at 12.2 volts and 84% charged after a 10 minute drive from the last start up. I think I will get a second opinion. Also tonight when I came home from work, a 50 mile drive, I put on my 3 amp charger/maintainer and it displayed low. My charger never displays low on either my boat or jumper box which I charge periodically. It usually will display 70% or 80%. I'm leaving charger on overnight and I will check on it in the morning. Will post back later.


----------

