"Service Battery System" - Help with Battery Problems

[airomero83]

All right guys I need your help on this dead battery problem I been constantly having. 2007 Chevy Avalanche. One morning battery was completely dead...couldn't even jump it. Took it to AutoZone thinking it was a completely dead battery but turns out battery is all good and they charged it completely. 2-3 days later of driving, battery was dead and can't turn truck on again (all interior lights and everything working). This time I can jump start it and let it run for a while. I proceed to remove negative cable with truck on and let it run for 5 minutes and stays on. Alternator good right?

 

Take it back and they tell me battery is good again and do a load test and tell me alternator is fine...but that apparently battery is not being charged. So it's gotta be a connection problem? Any blown fuses/relays I should check as well?? I've had issues with AutoZone when they have told me batteries were good when they were really bad. Should I second guess them? Anything else I should look for? I have a feeling it's the alternator. When truck is running, the battery gauge on instrument panel is a little over 14V so battery appears to be good.

 

Thanks for all the help!

[gmtech4]

its charging at that voltage ,,,,

 

you should have a load tester squeak some amps out of alternator to be sure and a parasitic draw test done also,and while they are at it ,charge the battery completely and load test the battery ,,

[Jsdirt]

I've had this issue with mine since day 1. Killed the battery almost completely listening to the radio while working out in the barn when the truck was 4 days into my ownership. Was able to bring it back with the charger I have, & I had the dealer tweak the computer for a little more output -- the alts these days are computer controlled. When they sense a full charge, the field is cut & the alt becomes just another idler pulley. Apparently, when it charges can be adjusted. Now that my truck spends more time sitting than anything, the battery will get weak after a couple weeks of no use. Most computer controlled vehicles have a constant , small, milliamp draw on the battery, so when they sit, an occasional charge is mandatory. Price we pay for "progress" I suppose ...

 

 

For the cost of a good battery, you can get yourself a charger that will pay for itself many times over. I brought my battery back with this, and HUNDREDS of others that were ready to be scrapped. Well worth the money. The key is the temperature sensor. It also has technology that supposedly breaks up sulfation. I can tell you this: IT WORKS!

 

You can shop the net for a better price, but you can use this to get all the info on it: http://www.northerntool.com/shop/tools/product_200326706_200326706

 

EDIT: Looks like they cheaped out and don't include the temp. sensor anymore - make sure you get that sensor!

[airomero83]

Thanks for the suggestion and sounds like a good investment. Definitely picking one up. And not surprisingly, it was a dead cell in the battery. ALWAYS second doubt those autozone guys. This has happened one too many times for me

[07sierra8.1]

I know this may sound odd but it happens to my dads Chevy Work van all the time, do you have anything plugged into a cigarette lighter that is hot all the time? If so unplug it! Even if its a cell phone charger with no phone attached..My dad went through hell and high water, couldnt figure out why his battery kept going dead overnight yet the battery load tested fine...he has a dewalt charger for his 18 volt drill battery plugged into cigarette lighter and even with no battery in the charger at all..it will kill the battery over night, he unplugged it and for weeks the battery didnt die, then one day he left it plugged in (again with no battery in the charger) came out next morning and battery was dead.

[Jsdirt]

Airomero, I'd be willing to bet that charger would more than likely bring that dead cell back. It's amazing what that charger can do. Not all the time, but 90% of the time i can bring a battery back.

 

The batteries in my John Deere lawn tractor & Polaris ATV were both dead within a week of ownership, back in '05 when they were new. I managed to float them along with a conventional charger until '08, when there seemed to be no life left in them. Used that new charger in '08, and both batteries came right back and held a charge.

 

I just replaced the Polaris battery last week, and the John Deere battery, which most people would've scrapped already, will go on in service for season #8. Only reason I changed the Polaris battery is due to the constant FI draw. I use it mostly for plowing. Between idling, and running the winch, heated grips, heated seat, and heated thumb throttle, it puts one hell of a load on the battery. Without lots of high RPM run time coupled with the parasitic draw, the battery would be weak whenever I started it up on cold winter mornings. The battery is actually still good - I just went to a AGM deep cycle instead.

 

That charger is well worth the cash.