what's draining my battery ?

[mechtech2]

Who says the battery and alternator are OK?
You have to check them - no big deal.
Power and ground cables have to be clean and shiny at BOTH ends.
This is where you start with an unknown car.

A simple common multimeter can be used in series with the + or- battery cable, and fuses can be pulled after you get the basics perfect.
Check online forums for the particular vehicle and dealers for chronic problems that cause this.

 

[tmorris1]

Originally Posted By: Vikas
Do not waste your time trying to find what is draining your battery. First replace it and if the new battery starts dying on you, then you start investigating.

- Vikas

What if the battery is only a month old? Then you just wasted $70-100 on a battery if the battery never was bad to begin with.

 

[Vikas]

That is different story. If the battery has more than year on it, replace it. I had experience with an year old battery dying if the car was not started for three or four days in a row. I spent lots and lots energy in computing the drain current etc. On late model cars, it takes quite a while before drain current stabilizes and if you disconnect/connect the battery to insert ammeter in series, the entire cycles starts again.

If you are NOT 100% sure of the battery, replace it first before trying to find the drain. Do not trust any checks done by the parts store. If you have marginal cell in it, you will have lots of unexplained issues with it.

- Vikas

 

[GMBoy]

I just emailed you several TSB's for your review. Hope it helps you!

 

[kenwin30]

thanks alot gm boy, if my battery goes dead again, i will contact my dealer about this problem !

 

[Gary Allan]

Originally Posted By: StevieC
If you can't wait that long you could hook up an AMP meter around the positive wire and start pulling fuses until you see the amps drop off to almost 0 and that will be your circuit.

Steve


This is the way.

btw- My son is driving a demo Rendezvous ..that apparently has this problem from the factory. It's allegedly the radio (its got a few bells and whistles). If it sits too long, dead battery. They don't even intend to fix it due to the cost of the radio.

 

[StevieC]

Scrap-Yard for a radio?

 

[aaxb970]

Research Onstar staying on. I read a TSB or recall about this but cannot remember where......

 

[toyota62]

Parasitic drain must be below 30mA to keep the battery in cranking condition over 28 days.As stevieC said connect a Amp meter lock the car notice the current draw.It may take up to one hour to all modules to shut down.When all computers on sleep mode current draw must be around 30mA mark.If you have any after market acc.they must be off or disconnect first.Some fuses power up more than one device so beware.Ex: Fuse box cover says power mirror but the same fuse may power up the body control module as well.

 

[toyota62]

Most of new GM cars charging system design to pump up to 15.5V to keep the calcium batteries fully charged.Down side slightly high fuel consumption and shorter battery life.Most of time You cant go pass more than three years on batteries on these cars.On older cars you can go up to 5+ years with out replace a battery.

 

[Craig in Canada]

Originally Posted By: kenwin30
got a 07 yukon xl with 52k, got it last week and i haven't drove it much since, got in it this morn and it wouldn't crank, battery was completely drained. i read on another forum where this model has had a problem where the computer stays on after everything is turned off. therefore the battery is being drained without you even knowing? anyone here ever heard of this, and if so, can this be fixed without carrying it to the dealer?


This situation can absolutely occur. You should be able to find a TSB# for this issue, if it exists for your model, and your dealer should fix it for no charge. I know that a certain run of the BMW E39 530is had certain firmware revisions in a module that wouldn't shut down and could drain the battery. All that was required was a firmware upgrade. Why not GMC?

 

[MrCritical]

Be sure nothing is plugged in the lighter or accessory plug ins.

If the aftermarket dvd isn't wired to the fuse box under the hood, disconnect that. There is a bulletin from GM telling the aftermarket companies not to wire accessories to the fuse box inside the vehicle.

Blower motors have been known to stay or come back on as well. Find out what the draw on the battery is when the vehicle is off.