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View Full Version : What does your battery charge at???



Mewsy
05-18-2006, 04:04 AM
My battery has been not holding its charge (90, 525i M20). On the OBC, using the hidden function 9, it says that it is charging at 13.50v when the car is running. Is this normal?? I dont know how old the battery is, I have had the car for just over 2 years, and haven't changed it yet.

BigKriss
05-18-2006, 04:28 AM
mine charges at around 13.8v according to the OBC

joshua43214
05-18-2006, 07:57 AM
The battery is the heart of the system, if the battery is faulty, it can throw of the voltage readings from the alternator. If you are having low charging voltage volts with a bad battery, replace the battery before you take the alternator voltage readings seriously.

You need a load tester to check alternator charging with a bad battery, and it will only be accurate if the battery is borderline. I have seen countless alternators fail output tests and then pass when the battery is replaced.