Is there a mechcanic in the house? Charging issues - BMW Forum

bimmernut · 06-02-2009, 11:17 AM

Hello,

I have a 2006 525xi with 58,000 miles. I dont know if I should buy a new battery or should I have my alternator replaced. About a month a ago I notice when I start my ignition it seemed like it was having a hard time before it would start the car. Then about a week or so later I tried to start the car and the battery went dead. I boosted the car and it started the car. I drove the car to my destination about 15 miles. When I got back in the car the car would not start again so I boosted the battery again. Then I went to mech who had a heavy duty charger and charged my battery for about an hour or so. The car battery seemed fine and started the car everyday for about a week until this morning. The battery is dead again. My question is do you think at 58,000 miles my battery just needs to be replaced or do you think my alternator is the problem? Any advise would be greatly appreciated. I would take it to the dealer but the car is out of warranty. Thank you

witeshark · 06-02-2009, 11:25 AM

A first guess is the alternator, since the one hour charge held up for a while.

cjscopp · 06-02-2009, 11:30 AM

A quick charging system test will be well worth the money. It's either the battery or the alternator so it's 50/50 but the alternator is much more expensive than a new battery. It would be wise to go and have the charging system checked before you replace anything.

bimmernut · 06-02-2009, 11:41 AM

Quote:

Originally Posted by cjscopp

A quick charging system test will be well worth the money. It's either the battery or the alternator so it's 50/50 but the alternator is much more expensive than a new battery. It would be wise to go and have the charging system checked before you replace anything.

Thanks for the quick response. Is this test sold at autoparts store or do I have to go to a mechanic to have this test done? Do you think an alternator can go at 58,000 miles?

bimmernut · 06-02-2009, 11:46 AM

Quote:

Originally Posted by witeshark

A first guess is the alternator, since the one hour charge held up for a while.

That was my guess too. As mentioned by cjscopp the alternator is more expensive to replace then the battery. I think I will have a charging system check done on the car as cjscopp suggested.

I never heard of this test before. Waiting to find out where I can go to have it done or can i get the test at an autoparts store.

witeshark · 06-02-2009, 11:59 AM

Many auto parts store should be able to do it; I'd have look at their web sites or give a few of them a call.

cjscopp · 06-02-2009, 12:08 PM

It is a simple test that many auto parts stores do. They have a wheeled tester they connect to the battery and then apply a load to test the output capacity of the alternator. Takes just a few seconds and you know which component is bad. Call your local Kragen/ Shucks or Auto Zone type parts store and just ask them if they do charging system tests..

bimmernut · 06-02-2009, 12:47 PM

Witeshark, cjscopp you guys are my hero. Thanks for your help

Cas · 07-18-2009, 02:54 AM

Over here you can buy a little bit of kit that plugs into your cig lighter and tell you if your battery and /or alternator is working as should.Red/Orange/Green lights