Typerod

So a few weeks ago, my 07 Tahoe needed a jump start. The vehicle wasn't driven for about 12 days. The battery is new, was purchased back in March 2010. Its garaged kept, not exposed to totally cold outside temps here in Central VA. I understand 12 days is sort of a long time not to drive a vehicle and expect the battery to hold charge. The car is driven about 3 times a week mostly on long drives 1 - 1.5 hr (1 way) trips about 130 miles total.

Today I started the car and it was very slightly hesitant to start, it just wasnt a nice crisp start. The car was last driven on 12/04. I believe there was a service bulletin a while ago about the 07 Tahoes having battery issues or something about the BCM constantly running, and I think the fix was a s/w update. I believe my s/w is up to date on the car, but one thing that keeps happening is that when the battery dies, my engine hours are resetting back to zero. I wonder if there is some sort of slow drain or maybe my alternator is not up to par. I had the battery checked and it passed. My next step is to have the alternator tested.

Not sure what else could be the cause. If the car loses power like mine, will it lose the s/w updates that happened in the past?

Tthanks for any input!

badOHtenTAHOE

ask around or search on how to do a "parasitic draw test". those symptoms lead me to beleve thats the problem. something is staying out when it shouldnt be even if u cant see it

Typerod

I'll look into that, dont know how to do that myself, I'll see if dealership can hook me up. Thanks for giving some direction, much appreciated!

RacerX

Maybe the battery is no good. Just because its new doesnt mean anything. I have an ongoing romance with Advance Auto Parts because the Titanium line battery I bought in 2008 never lasts for more than 13 months. And with a 3 year free replacement on a 72 month warranty, they have replaced the battery 4 times already, as recently as October. So just because its new doesnt mean its good.

Typerod

Very true. I had the batt. test at my Chevy dealer, and everything checked out OK. Thinking of going the 2nd batt. route. I just can't find concrete suggestions and installation videos/instructions. I've searched on here, but nothing that really helps me since I'm not savy with these things.

73shark

I'm firmly convinced that the NBS is hard on batteries. I drove 500 miles w/ it charging ~15V and then it goes to ~12V for the rest of the trip.

Most of the time if I leave the key in the Run position for a minute or two, I'll get a "Low battery, start engine" warning.

Typerod

@Shark, what does NBS stand for?

in2pro

NBS is New Body Style

I agree, it seems the battery should be larger for the amount of power the vehicle requires for so many modules and systems

73shark

I'm beginning to think that extra battery tray was for a second battery and the bean counters nixed it. I've never gotten a satisfactory answer as to why it's there.

Typerod

Im definitely going to go with the 2nd batt. But I had a question, when one of the batteries needs to be changed, what is the proper way to change it out? what i mean is, is there a certain order to remove one battery before the other. Do I disconnect both to change the bad one or can I leave the good batt connected and just swap out the bad one? Thanks. Ii finally found the part numbers for the Police tahoe aux batt cables, but there isnt a part number for an isolator/switch. I wonder if it even uses an isolator?

So many configs Ive been seeing online, just dont know which one to go with. I'd like to go with an isolator just so theres priority with charging. Any input/info/suggestions are welcome and I need them! lol! Thanks.