BMW 325ise not working - battery keeps going flat?

Question

Hi, please can anyone help…

I have been having problems with my BMW 325ise 1995 with the battery going flat after leaving the car over the weekend. The RAC came round and said the battery is fine when charged up and they cannot find a problem.

When I checked the car at an electronics car firm they also said the car is fine. It happened more often when I put in a SatNAV dvd player.

I am not sure if that’s timing or what. Also the car battery goes down in colder weather more quickly.

I have a bad back and its not help me changing the battery all the time for recharging.

Any help would be much appreciated.

Answer 1

There're 2 possible issues here.



1. Battery is too old .How long have you had this battery? If it's 4 years or more, it's probably time to change it. Not sure if you can trust the RAC guys.



2. The parasitic drain on your car is too high, possibly caused by your new DVD player; it is possible that the DVD player was wired incorrectly, causing it to drain the battery. It might be something completely different. Have someone measure how many milliamps your car draws from the battery. This can be done quite easily even with a regular digital multimeter.



Cold (sub-zero) weather does dimish the battery power somewhat, but not enough to cause it to be dead over a weekend.

Answer 2

well from what you explain then you have not carried out any diagnostics on the alternator to check that this is putting charge into the battery check battery output before starting engine with voltmeter and then start the engine leaving the meter in situ if when you raise the engine revs the voltmeter reading increases then the alternator is functioning if no movement or only slight movement then alternator duff.

Answer 3

id also agree that the new goodies you installed may be draining the battery, as well as the age. Also look into the alternator, which may need replaced; it may be as simple as simply tightening the belt; or as much as replacing the alternator. All of which are simple.



also consider www.bimmerforums.com. I find this site very convenient and most people are pretty knowledgeable.

Answer 4

More likely is your battery is not holding a charge. I would recommend replacing your battery with a new (and keep the warranty).