Battery mysteriously dies

I have a 2002 3.0L BMW X5. The car runs great but every week or 2 the battery mysteriously dies on me? There is nothing left on in the car as I have checked on this. ANy ideas??

Have you had the Battery load tested?
Do you know the age of the Battery?
Or how many times its been depleted below 50%?

Have you tried pulling the fuse on a few known power drains like the Becker BM54 Radio Module?

Have you used the cluster menu to check float voltage and charge voltage?

I's also be very careful of "Jump Starting" the vehicle..... a slow trickle charge with the battery out of the vehicle is preferred, having the battery in the vehicle would be the next best option.

I did bring the vehicle in to have the battery and the alternator tested and battery was good but was told that the alternator while still producing enough charge to pass was on the low side of the scale. I have not pulled any fuses or checked the cluster. Do you know of a site that illustrates how to do this??

google and youtube

Originally Posted by Trevor Evans

... I have not pulled any fuses or checked the cluster. Do you know of a site that illustrates how to do this?

Which instrument cluster do you have? Could post the instructions, but not enough vehicle information.

The low cluster only has one button (on the left side) and uses a graphic display for the Check Control warnings. The high cluster has two buttons (left & right) and has a 20 digit alpha/numeric display where the Check Control warning appear (and you can also program the OBC features to appear there).

Again, which instrument cluster do you have?

I don't want to steal this thread, but eventhough my battery was recently replaced, I have noticed that my lighting is somewhat dim during initial startup, then it normalizes after minutes of run time.

I have the high cluster, so how would I go about being able to look at my voltage levels and any other operating information for that matter...??? I think this information will be very valuable to other X5 owners.

Thank you !!!! - Victor

Originally Posted by QSilver7

Which instrument cluster do you have? Could post the instructions, but not enough vehicle information.

The low cluster only has one button (on the left side) and uses a graphic display for the Check Control warnings. The high cluster has two buttons (left & right) and has a 20 digit alpha/numeric display where the Check Control warning appear (and you can also program the OBC features to appear there).

Again, which instrument cluster do you have?

Originally Posted by virso

...I have the high cluster, so how would I go about being able to look at my voltage levels and any other operating information for that matter...??? I think this information will be very valuable to other X5 owners.

Thank you !!!! - Victor

Here's a link that has more info (a brief description of each of the 21 TESTs)...click on the thumbnail images and they'll explode into a larger view. There are also instructions on how to unlock the LOW instrument cluster (it only has the left button on the cluster) if keep scrolling down the page: http://www.cardomain.com/ride/313409...series/page-6/

Here's instructions for how to UNLOCK the High Instrument cluster...there are also multiple videos on YouTube on how to unlock the OBC of BMWs...as well as older threads in this forum and many other BMW forums:

Thank you Silver... Let me 'click' away...