I'm sure this is a very common question, but again.

My H2 kill 3 batts in 4 month, obviously, no more batt warranty. During this time, I make a couple of tests and radio, radio amplifier, car lighters, washer pump, power locks, SOS system fuses are disconnected, but last night it killing the batt.

Any of you has starter, alternator, power seats, power mirrors or wiper motor issues that drain the batt?

Any help will be really appreciated.

 

 

My 2003 had an intermittent battery drain, turned out to be the ignition switch, the key would come out but the switch would not shut off the power and battery dead over night.

 

Need to do a parasitic battery draw test and figure out what is staying powered.

 

update:
set the multimeter in line with the H2. Instantly, the reading was 0.682 Amps, but after 30 to 40 secs, it drops to 0.002 Amps.

So, I don't understand what is happening.

Still looking

 

You need to monitor more than 30 to 40 seconds. Grab a beer and monitor the cycle, while pulling fuses.

 

Also search here on the forums for parasitic draw. I've posted some time back a document from GM that details that test on an H2 and states how long it takes for certain modules to "sleep". Also, if your Onstar is no longer used, definitely remove the fuse for it as that is a known culprit, especially if it is an early analog one (continually searching for an analog cellular signal as well as satellites for GPS). I believe that is the VCIM fuse in the underhood fuse box if I remember right.

 

My hummer had a tracking system installed. I can’t remember what it was called but it is now owned by lo lack. My truck battery would drain all the time. Once I removed the tracking system and stopped buying batteries from gm my truck battery had never died.

 

@Hummerrican
There will always be a tiny draw. That is to keep the electronic memory going, like clock, etc. So the 0.002A you are seeing is likely correct.
The initial higher reading was likely your courtesy lights.
Looks normal to me.

 

are you sure the alternator is not overcharging the battery and boiling them?