skipper

Hello all,

I have read through the forums here and on other forums but have not had any luck.

I have a 2004 530i, no comfort access. The battery is a Bosch which is 3 months old. It ran fine for 3 months and now every morning the battery is completely dead. If I charge the battery overnight the car will run fine all day long. I can drive to the mall and stay there for 4 hours and the car starts right up. I do not get any error messages that others have stated such as high battery drain.

The battery is clean, new, no moisture. In some of the other posts they suggest that the battery should be programmed to the car. It ran fine for 3 months without the programming though and now every night it completely drains. Other posts say that the car may not be going to sleep. I do not hear it making any sounds 20 minutes after I lock it.

I do not think that it is the alternator since I do not get any errors and like I said the car runs fine all day long and starts right up after being parked for a long period of time.

Does anyone have any idea what this could be?

Thanks.

pcy

Disconnect the IBS connector and check the following morning if those symptoms persist.

KyleB

^^^this

ill assume the car is an automatic. check on your car after about 90 minutes. if the LED next to the park indicator next to the gear select is still illuminating, your car is not 'sleeping' as it should.

skipper

Thank you both. I will check on both of these after I charge the batter overnight tonight.

GOLD PANDA

Had this issue often and regular, until I went to their battery tender unit.


this approach has totally avoided these inconveniences going forward for me.


especially true when not driving the BMW on a regular basis.


best of luck regardless!!


BEST REGARDS

tonyb635

If the battery is three months old why don't you take it back fir a check? Maybe there is something wrong with it? Seems pointless to start changing parts on your car when you should have a free check and maybe a replacement with the battery.

skipper

I forgot to mention in my OP that I did have the battery tested and it was good. And I do have a tender but it is inconvenient to use because I do not park in the garage.

FaintReality

My OEM battery is fairly new and my car dies quite often as well, but not nearly as quick as yours. I have checked my led near the shift indicator and it does indeed go off after 30-45min, so I assume the car goes to sleep properly. I assume my issues are from the fact that there is a huge current draw every time I start the vehicle and I take short trips, not giving it enough time to charge back up :-/

Good luck. It's my only complaint with the car so far.

BimmerFan52

You need to give us a little more info and maybe do a little more measuring and analysis. Do you have a multimeter to measure battery and alternator voltage? Or buy a plug-in voltmeter.

I assume you jump the car to start it. After you run it a while does the battery fully charge? What is the output of the alternator? Did you check that the battery cables are tight?

If the battery fully charges (12.6V after driving and then measured after sitting for 30 minutes) and the alternator puts out 14.2V to 14.7V while the engine is running (after 15-20 seconds of ramp-up) then you most likely have a parasitic drain.

As pcy suggests, the most common parasitic drain for E60s in the 2004-2006 range is a failing Intelligent Battery Sensor (built into the negative battery cable) as the IBS design was not properly waterproofed and moisture or water contact can lead to failure of the IBS processor. The IBS is designed to measure battery state of charge (including when the car is at rest). When operating normally, if the IBS thinks that auxiliary equipment is such as the radio, heater, etc. is on when the engine is not running and draining the battery, the IBS can wake up the ECM to turn off these loads. The wake up function is designed to be performed only once, as the ECM draws large current while running.

Unfortunately, when the IBS fails due to moisture it can repeatedly wake up the ECM, causing the battery to be quickly drained during the night.

In order to fully diagnose, you need to be able to measure the battery voltage while the car is at rest over a 6-8 hour period and document the battery being run down. Then disconnect the blue lead coming off the IBS (the communications line to the ECM) which will prevent the IBS from waking up the ECM.

If the battery no longer runs down then the IBS is your culprit. If you are a DIYer then purchase the IBS off the Web and install yourself, or have your local Indy put in a new IBS.

If the battery still runs down with the IBS disconnected then you will need to continue your search for the drain source, again, assuming the battery is charging properly and the alternator is outputting voltage properly.

tonyb635

Sounds like your car might not be going to sleep. The past few days my battery jack lite has illuminated two times due to me going in and out of the car, starting it to move it then off. But it doesn't completely die. Bimnerfan and pcy has some good advice that is fairly easy to check.