So I go to start my 2005 530i and the battery is dead. I know for a fact no lights were left on. I give the car a jump and starts fine. I have an appointment next week to change the brake fluid, filter, and oil change. So the next day go to start my car and its dead again! I jump it again but now it shows that no service is due! I would normally think its the alternator but about a year ago the dealer was checking things in my car and noticed the alternator was faulty and replaced it. I doubt a second alternator can go bad in another year? My battery was fine the last time they checked it in the spring time. So now I am going to have them take a look at it during my appointment but I am kind of worried that they won't perform the service thats been due! Any experience on this?

 

An alternator has moving parts which can go bad anywhere, anytime, though the probability of this happening within a year is low. It shouldn't take long for the service dept to find out whether its the alternator or the battery or both which are messed up.

What makes you believe that they won't perform the service? Also, are you at the end of the warranty period?

 

Well the last time I went in for an oil change I had a 1000 miles left and I asked them to do it with some other stuff I was getting done and they said they couldnt cause the I drive told them its not time yet! So I had to go back at a later time for that. I dont understand why all my service miles in the I drive would have changed but I really hope they understand and im not trying to take advantage of the free maintanence. I have 7000 miles left on my maintanence warranty and I think I will have to extend it.

 

How was your car parked? On horizontal plane or was it parked uphill or downhill. My battery died once when I parked the car at steep downhill. I guess the fluids mixed so that some impure sediments short circuited the battery. Hope you understood by bad? English here .

 

My car was parked in my garage like it is everyday so I am going to have to rule that one out. Thanks for the input!

 

Dear Sam the BMW man,

Your 3 (to 4) year old battery just might be a gonner.

Lots of short drives, with all the amp using features on, could do the trick.

Your dealer should give you a new battery for nothing, after all service visits you done.

 

Well when I went in the spring time the dealer said the battery looked good. Do you think its possible that it got bad in a couple months without it getting drained?

 

I had a similar problem and it turned out to be a bad cell in my battery. I even took it to Sears to have them test it before I brought it in to the dealer and they told me that my battery was fine.... Go figure... Anyway the dealer told me that it was just one bad cell in the battery and they replaced it (but I had to pay for it) because it supposedly isn't covered under my CPO warranty or the extended maintenance agreement.
Hopefully they'll warranty it out for you. And yes I overpaid for an OEM battery. I actually fell for the "OEM battery is better than a DieHard" story. Its been working fine ever since.

 

When that happened to you did it happen all at once or did you notice it happening slowly? To be clear when you started the car did it stagger a bit before it ended up dying all the way?

 

It wouldn't be the first time a "hideout bad" battery caused a problem.

To the BMW dealers!