Is the battery or alternator or something else?


I about three weeks ago I bought a 1992 520i BMW with about 147, 000 km (90K miles). Twice now I have had to have the car jump started (the battery is underneath the rear seat which was an adventure to find since the owners manual is written in German). I have had the charging system tested and the mechanic says the charging system is fine. The battery has the numbers 2006-06 written on it, which I am guessing is the year, and month it was installed. What other tests/steps can I take to avoid having this happen again? I already make sure all the lights, radio, fan, etc. are turned off prior to getting out of the car.



Did they check the starter? Could be a bad solenoid or other problem with it. Does it turn over at all?

The battery can be tested. A “load test” will tell you the true condition of the battery. I’m surprised they didn’t do that when they tested the charging system. In the US most auto parts stores will test batteries for free.

Some vehicles that have hard-to-access batteries have a set of jumper terminals under the hood to make the job easier. My son’s MINI, built by BMW, has this feature.

The car normally has no problem starting, the clue I get that my day is not going to go well is the lights on the dash are very dim when I put the key in the ignition. To the best of my knowledge the starter was not checked, how would I check the starter?

The mechanic connect a meter/gadget directly to the battery and while the car was off, then had me turn the car on, and then increase the RPM to 2,000. I am not sure if this is the load test method you are describing. The cost was minimal ($5.00)