Richardbenz 0 Report post Posted November 30, 2007 (edited) Hi My 1989 735i battery is not quite holding its charge and I believe it is the alternator. Does anyone out there have one lying about somewhere or can suggest what is the best thing to do in getting this issue worked out. Thanx Edited November 30, 2007 by RichBMW Quote Share this post Link to post Share on other sites
jochen 4 Report post Posted November 30, 2007 My 1989 735i battery is not quite holding its charge and I believe it is the alternator. If a battery cannot hold a charge, then the battery is faulty The alternator charges the battery, but has nothing to do with the battery HOLDING its charge. The ability to hold a charge is a function of the battery, and only the battery. If you think the battery is not being charged fully, then you can suspect the alternator and/or battery But for a battery not HOLDING a charge, it can only be a faulty battery Quote Share this post Link to post Share on other sites
topcat 11 Report post Posted November 30, 2007 a good clue if something is amiss is the battery warning light in the dash.if that is glowing then yes the alternator has issues.i've got one around somewhere if needed Quote Share this post Link to post Share on other sites
Richardbenz 0 Report post Posted November 30, 2007 Hi My 1989 735i battery is not quite holding its charge and I believe it is the alternator. Does anyone out there have one lying about somewhere or can suggest what is the best thing to do in getting this issue worked out. Thanx Thank you for that, will need to look for a battery in that case. Regards Quote Share this post Link to post Share on other sites
Richardbenz 0 Report post Posted November 30, 2007 If a battery cannot hold a charge, then the battery is faulty The alternator charges the battery, but has nothing to do with the battery HOLDING its charge. The ability to hold a charge is a function of the battery, and only the battery. If you think the battery is not being charged fully, then you can suspect the alternator and/or battery But for a battery not HOLDING a charge, it can only be a faulty battery Hi again, te mechanic tested the battery with his tester under load and it read about 13.45, he said that it should read at least 14, does that indicate a battery that needs replacement, he had charged it overnight previous. Quote Share this post Link to post Share on other sites
bekker 7 Report post Posted December 11, 2007 I'm with Topcat on this one. Get the alternator checked out too. I've just been through this myself, went out and bought a new battery only to find out the alternator brushes needed replacing. The brushes are dead easy to replace (on a Bosch alternator at least) and about a quarter the price of a new battery. Good luck Quote Share this post Link to post Share on other sites