Need help parasitic drain

[mdefalco25]

So my car has shown indications of a weak battery. Four years old, clock is not keeping up and if I turn car off after driving within a minute I get the low voltage warning and battery icon. I took car into dealer today to replace battery. They tested battery and said it came back strong and stated I have a parasitic drain. Dealer wants to do a parasitic drain test for two hours, but before I spend the money wanted to see if there was anything I could try or look into? Really am shocked it is not the battery and now worried it is something worse. Any advice is much appreciated!

For background, it is getting colder in IL and that's about when I noticed this happening and car is a 2008 E92 M3 with 41,000 miles.

UPDATE: 1/1/2013 picked up car today from dealer after battery was replaced. Car had been sitting in their shop for a couple of weeks waiting on new tires. Anyway, clock was set correctly and took car for a little spin. Parked it and put a battery tender on the car around 3:00 today. Four and a half hours later it still appears to be charging so guessing I have a parasitic drain. Guess it's back to the drawing board and figure out what is drawing power

Thanks,
Mike

[kscarrol]

Sorry, sounds typical dealer BS. A four year old battery is likely the issue. What do they want to charge for this "test"? I would bet a lot of $$$ that after they charge you for two hours of labor + they come back and say it's the old battery after all...

[mdefalco25]

Ugh, just tested my battery. Battery passed, parasitic drain failed. Car is drawing 8.29A when everything is shut down. Back to service it goes. This one may hurt

[kscarrol]

Ouch! Sorry to hear that, thought for sure dealer was trying to pad the bill... Hopefully nothing major.

[mdefalco25]

You and me both on both accounts!

[kaigoss69]

Sounds like total BS. Battery is 5 years old. Time to get it changed.

[mdefalco25]

Had Autozone test battery today. Tested just fine and showed an 8 amp drain when everything was off... Still think it's BS? Would like to know before I dump all this money into the test tomorrow. Please let me know your thoughts.

[BPMSport]

Originally Posted by mdefalco25

Had Autozone test battery today. Tested just fine and showed an 8 amp drain when everything was off... Still think it's BS? Would like to know before I dump all this money into the test tomorrow. Please let me know your thoughts.

I've been through and seen so much battery BS at the dealership, that personally I would just replace the battery. An energy diagnosis on the car usually comes back with "Unfavorable Driving Conditions" as the culprit. I have all of the factory tools and have run that diagnostic. It's useless unless there is a huge draw.

Make sure all connections are tight and measure the voltage before starting to see what it is.

[mdefalco25]

Thanks for heads up. I dropped car off today and told them to just replace battery. Hopefully that will take care of it! Thanks again. Wil report update once I know more.

[djseto]

I had the clock issue. I took my car to a local mechanic that works on BMWs and had them replace the battery and register it with the system. Cost me $250 for a 720CCA (900 CA) Interstate Battery. The dealer wanted $500. My problem went away. I've also noticed the car "boots up" quicker now. I've read that the car has some battery management system that prioritizes what starts up and gets juice so that enough power is left to start the car when the battery gets weak. So far, so good for me. My car is an 08 with just about 45K miles.

[Longbow64]

First had the dimmer reset on my instrument cluster. Next couple starts my clock reset. Then I got a battery discharge warning. Then a battery low warning. Then the car died when the dealership tried to start it to test the battery. Replaced my battery. $360. I gave them the SIB about the cable, but figured if I had a cable issue it would have died a long time ago. Car's been running great since. Three other M3s were there for the same thing.

[djantlive]

8 amp is a lot of power drain. The car needs to be locked and doors and trunk closed. Car goes to sleep after about 15-30 min so testing it then is more proper.

You should see less that 50 milli amps. Search car battery drain test on you tube. You can test this yourself w a $20 multimeter.

[mdefalco25]

Djantlive to your point, I had the parasitic test down right after shutting car down so you make an excellent point on why it was probably so high. I forget that the car does a series of things before it goes completely off. That would likely explain when I personally did the test why it was 8 amps. I wish I knew how the dealer did it but regardless they replaced the battery. Sadly, I won't know what the effects of changing out the battery are until next year. Tires are so bald (metal is starting to come through) I ended up leaving it at dealer until my new shoes come in. Also picked up a battery tender since I don't drive very far to fully charge battery so hopefully this is all the car needs.

[djantlive]

it's easy to test it yourself. i would do so after you get the car back. roll down the windows. you can trick the car to think the door and trunks are close by manipulating the latches. leave the car for 30 mins and come by to measure the current.

[kaigoss69]

Originally Posted by mdefalco25

Had Autozone test battery today. Tested just fine and showed an 8 amp drain when everything was off... Still think it's BS? Would like to know before I dump all this money into the test tomorrow. Please let me know your thoughts.

Autozone doesn't know what the hell they're doing. All you likely need is a new $90 battery and a registration.

[mdefalco25]

Well I wish it were that easy. I had to go with the OEM batter otherwise the dealer wasn't going to register it and I didn't have much time to shop around. So this go around I'm out just under $500 bucks. Next time when I can spend more time around this I will not settle with the OEM battery, however, a lot of people say they would stick with OEM and this being my first BMW I didn't want to take any chances. And I realize Autozone isn't an ideal choice, but it was free and was really trying to determine what was going on with my battery at a high level before I went through all this.

[mdefalco25]

Updated thread...

[W///]

Originally Posted by mdefalco25

So my car has shown indications of a weak battery. Four years old, clock is not keeping up and if I turn car off after driving within a minute I get the low voltage warning and battery icon. I took car into dealer today to replace battery. They tested battery and said it came back strong and stated I have a parasitic drain. Dealer wants to do a parasitic drain test for two hours, but before I spend the money wanted to see if there was anything I could try or look into? Really am shocked it is not the battery and now worried it is something worse. Any advice is much appreciated!

For background, it is getting colder in IL and that's about when I noticed this happening and car is a 2008 E92 M3 with 41,000 miles.

UPDATE: 1/1/2013 picked up car today from dealer after battery was replaced. Car had been sitting in their shop for a couple of weeks waiting on new tires. Anyway, clock was set correctly and took car for a little spin. Parked it and put a battery tender on the car around 3:00 today. Four and a half hours later it still appears to be charging so guessing I have a parasitic drain. Guess it's back to the drawing board and figure out what is drawing power

Thanks,
Mike

Next time, go with a Sears battery. Depending on what kind of battery tender you have, it might take more than 4 hours. I have the smallest one available and it takes more than 12 hours to fully charge (only 1.5A). Let the car be, and see if the issue is gone.

[mdefalco25]

Thanks for the heads up. When I checked it this morning after the battery tender had been on for over 12 hours the green light was flashing which indicates the battery had at least an 85% charge. So I guess it was really low. Going to give it one more try and go from there.

As for going w/ a Sears battery, if I did my local BMW dealer wasn't going to register the battery so was feeling a tad trapped. I will next time reconsider if there is a next time when it comes to replacing my battery.

[Budge]

I've been having the exact same problem. When it started getting cold this winter, my car started giving me a low battery signal. Then the comfort access stopped working, and shortly after I couldn't start the engine. I took it to the dealership and they tested the battery. They said it was fine, that it just needed a charge, but that I must have a parasitic drain. They blamed my amp setup. I have a JBL MS-8 and a JL Audio amp. But both amps are triggered by the headunit only. My car is still under warranty and I've had the amps for almost two years with no problems. Is it possible the extra amps caused a slow parasitic drain or wore out my battery prematurely? If so, what can I do about it?

[passing]

wait until your car goes to sleep. pull out the multimeter.

pull fuses until you know where the draw is coming from. problem solved.

[mdefalco25]

Yeah, I know how to test it, but not sure how to fix it if it's something major. I'm guessing it's typically more than a fuse causing the issue? Was going to have it looked at if it starts getting worse. Right now, I put a battery tender on each night and it is showing that it is capable of charging to the full extent so that's encouraging. Meaning, if there was a draw it would never reach the full charge on the Deltran charger. This morning the light was a solid green which means it monitors and charges when necessary. Fingers crossed it was just a bad battery.