Demans sucking my H2's Life
 

I know this has been discussed before, but I have not seen anyone post an answer to the mystery.

If I leave my H2 for a week without starting it, the battery goes completely dead.

Anybody have any ideas?

Re: Demans sucking my H2's Life
 

I had the same problem with my H2 and it's even worse with my H3. After trying different batteries and cables I installed a CTEK charger. I have it plugged in whenever I'm not driving it. It works great, no more problems!

Re: Demans sucking my H2's Life
 

Now thats an idea but what a pain. I may have to resort to this, but I wish I could just fix the issue.

Re: Demans sucking my H2's Life
 

Had the same problem over a year ago. what a pain in the azz it was. My truck was at dealer for about 3 wks to figure it out and GM/Hummer sent people down to figure it out. About once a week in the middle of night, something would turn on and run at about 300amps just killing the battery in a minute. I posted on here about while it was at dealer and got a lot of help from everyone. I used the ideas i got to give to GM. Sadly they couldn?t figure out exactly what was turning on ! They had all this equipment on it (looked cool) and still couldn?t figure it out. So they completely reflashed all the computers (after i gave them the idea) PCM/BCM/TCM/ onstar update, radio, etc and it worked! No problem since! I did install an OPTIMA D31A since i wasn?t crazy about my battery being drained tons of times by the dealer and not replacing it saying it was fine. So i was like whatever, ill go get a bad azz battery. Got it for 190 shipped to my door with coupon from advanced autoparts.

COMMERCIAL YELLOWTOP DUAL PURPOSE BATTERIES
MODEL NUMBER D31A & D31T
PERFORMANCE
Voltage 12V
Cold Cranking Amps @ 0 F 900
Cranking Amps @ 32 F 1125
Reserve Capacity 155
Capacity (C/20 rate) 75
Internal Resistance (ohms) 0.0025
PHYSICAL SPECS
Length 12-13/16"
Width 6-1/2"
Height 9-3/8"
Minimum Weight (lb) 59.8
Type/Post Terminal 3/8" Stainless
Steel Stud & SAE Post
BCI Group 31A & 31T

Re: Demans sucking my H2's Life
 

Is your onstar system active? If not try pulling the info fuse and try it. When you dont have an onstar subscription sometimes the module will wake up randomly and attempt to find a sat signal.

Re: Demans sucking my H2's Life
 

I pulled the OnStar fuse along time and it has done nothing for.

My problem is I am in Germany and there is no deler support for me. There is a guy near by who could do it but at my cost.

Re: Demans sucking my H2's Life
 

So I got a chance to do some testing this weekend and found the following:

Under the hood fuse box
TBC Bat - 140MA
IPC/DIC - 330MA
HVAC - 130MA
SEO B1 - 330MA
TREC - 20MA

Inside Fuse box
DDM - 45MA

I took each fuse out one by one and read the amps across the fuse terminals.
Based on the figures above does anyone have any ideas of where to begin my troubleshooting.

I am just getting sick of buying batteries for the Hummer.