Dead Battery

[H3PAC]

Well, almost dead. My new vehicle, with only 1,200 miles on it, has had progressively weak starts for the past 2 days. No problems prior. Barely turned over when leaving for work last night. Parked at work for about 9 hours and needed to call Hummer Roadside Assistance to have Sparky (I swear the guy's name was Sparky - you think I could even make that up?) come out with a battery pack and jump start it. Ran fine, charged right up from the alternator and no idiot lights or messages. Did not leave anything on....only factory/dealer installed electronics....it's a mystery. Any known issues that could cause a continuous power draw that resolves itself? Or, can a bad battery behave so strangely? Since I didn't see any idiot lights, and the battery seems fine now, is there any value in bringing it into the dealer to be checked? Or should I wait and monitor things for awhile? Should I stop using so many question marks???

[f5fstop]

One thing to check, well a few....
Make sure you cannot move the battery cables (Positive and Negative) where they attach to the battery. Grab the cables at the battery and see if you can move them back and forth. If so, get a 10mm socket and make sure the cam bolts on the cables are as tight as can be. (These new cables are terrible, MY OPINION ONLY, but if loose, they will cause some strange things to happen.)
Make sure the ground bolt on the fender, just behind the battery is tight.


If those are ok, take the vehicle to the dealer and have him run a midtronics test to check the battery. It could be starting to go. They can also check for a large parasitic load that might be draining the battery.

[Wisha Haddan H3]

Speaking of parasitic load, aren't the accessory outlets always on? So if you leave something plugged it, that would drain the battery. Or does the H3 stop battery drain beyond a certain point?

[f5fstop]

True, something plugged into an accessory outlet will cause a drain until no more juice is left.
The BCM will shut down interior lights if it sees no switch movement (and ignition is Off) in twenty minutes, but will not shut down the accessory plugs, exterior lights, etc.

[H3PAC]

Thanks for the quick reply. I've checked the cables and ground bolt. So did Sparky - remember him? All tight. I have nothing plugged into the outlets. So it's time to introduce myself to the local dealer.

[f5fstop]

NEVER trust a person named "Sparky" to test your cables....

[H3PAC]

The local dealer checked out my vehicle this morning and the battery tested OK. The tech tested it 2 additional times based on my story and oddly, it failed on the 3rd test. He replaced it. I'm sure glad this guy was on the ball. I could have been stuck in the middle of nowhere with my "tested OK - cannot duplicate problem" battery. Thanks to you guys and Scott Hummer in Allentown, PA.....oh, and Sparky too.

[DURAMAX TIM]

The day after we got ours, it wouldn't start and not enough power to call onstar.
thought someone left a door open or light on but it did it 2 more times the next day.
I just put the charger on it and took it to dealer for new battery.
Dealer said they put in 2 other batteries recently.

[MountainBlue]

Mine went @ 800 miles A-hole service writer at Galles & Davis tried to blame us. I ripped the general manager a new one over it and it got replaced. Then come to find out, a TON of people with ALL kinds of GM vehicles have dead batteries shortly after delivery.