I have a 08 Alpha with 18,000 kms on her.The dam battery went dead after leaving her in the garage for 2 days,not driven.Back in the late 2008 I had the stock gm battery go dead a couple times when it sat for 24 hours and the temp was very cold out.My dealer replaced the battery and all was fine till another very cold night,truck sat for 24 hours again and bingo,click,click,dead as a bone.I got a Optima battery after that and no more dead batteries untill now.Today I went to start the truck and dead as a bone with key stuck in the ignition.Gave a boost with my portable battery pack,and she fired up no proab.Seems to me that when she sits,not driven for more than a day or so she goes bone dead,even with a Optima battery.I tried the test of removing the positive battery terminal with the moter idleing and she ran fine 20 min or so till I shut her off.It cant be the alt,what else could drain the optima in 2 days.A while back,like last year this time,while i was driving,and the interior lights came on by itself.I tried to shut it off and it would not go out.After about a half hour of driving the interior lights went out by itself,it did this 2 or 3 times last year.Why does this hummer line have so many battery issues.I have owned GM trucks for 20 years and have never had a dead battery from sitting for a day,except when I left something on to kill the battery.The dealer,when I go there tomorrow,will just want to f_k with another battery again.Something is killing it,but where to look is the question.Anyone have any ideas...

 

When you park it in the garage, do you, by chance, leave the keys in the ignition?

 

Nope,the keys come in with me after parking it in the garage.Also,I have put two new batteries from the GM dealer already since 2008,the Opitima I put in was late last summer,its been good till today,parked for two days,not driven, and its bone dead.Just wondering,also,last year in the summer,the inside top interior dome light would come on by itself while I was driving,and went out by itself,20 to 30 minutes later.What would put power to the top dome light,when the switch was off and I could not shut it off...Makes ya wonder.I think my Alpha is possessed.Its pretty bad when you drive the Hummer to work,Im gone for 24 hrs,since my job is a railroad engineer,get back and click,click,click,then get a fellow co-worker to jump my truck with a 50 dollar mini van.The next time she dies at work, I will proably get a boost from the conductor who drives a smart car.I dont know if my battery cables will go down that far.Good thing I bought a portable battery pack last winter.Gotta get this fixed though, the neigbours are starting to peek through the cutrans.Anyone have any ideas on what else I can check....

 

Just rememberd today, the the dealer installed a LoJack Boomerang gps tracking unit on my truck,but was never activated.Could it be this,thats killing my battery..

 

I would start with the lojack unit and remove the power soure to it. Also if you have question on the dome light try taking out the fuse for it and see what happens. Right now you are better at troubleshooting it than the dealler. They will spen 20mins. on it and sell you something you possibly dont need right now.

 

i can run the radio all day it seems but let that xcdzsx dome lite on and its clik,clik time. (in most cars i owned)
the h3 times out to save the batt EVEN IF the lite is switched on, its part ot the incredibly complex controls. it sounds like some work backward

follow the book and check to see IF it really works right

tom

 

You have something drawing too much power when it's off. Any aftermarket items? Have the dealer check for voltage loads instead of just chucking a battery in it, cure the problem, not just the symptom.

 

Check all aftermarket items first. You have something drawing power when the car is off and the culprit is almost always aftermarket add ons, if you have any. I would start by eliminating the lojack and any other after market item first.

 

Thanks for all the info...I am going to get the lojack ripped out today,and have the dealer check the voltage loads also.I will post back if anything is found..

 

my 08 alpha came with a 350 or 500 cca battery from the factory couldnt tell how big it was with the battery cover, died first time it got cold up here and sat for a couple of days replaced it with 1050 cca had to "clearance" the cover but havent had a problem since