Hello, I have a 2004 525d. I recently purchased the vehicle, but i only noticed at home after 2 days that the positive on the battery was not tightened. After 2 days the battery died i think. I charged it, did a battery restoration and it came back to life, but i got he high battery discharge icon on the dash. everything was normal for like a month. Then one day suddenly it didnt start. there was no crank, no start and the battery died again. I replaced the battery, and everything was fine again for like a month, then i got the sos phone symbol on my dash, and my whole center console shut off. No radio, no park radar, no display, only the AC worked. I went home, next day it didnt start again. Now i cant get it to start. Luckily the car is at home, but there is not one mechanic or autoelektronical man that would come and maybe diagnose the car. I cant move the car as its quite pricey to rent a trailer, and i would not like to tow it to the closest big city(40km).

Can anybody offer me some insight what might be happening to my car?
Thank you,
Daniel

 

It sounds like repeated charging issues. The best thing to do is to actually check the battery voltage so you know what you're dealing with. A cheap multimeter will do what you need, or you can get a USB charger that includes a voltmeter so you can always see what the battery voltage is (should be over 12 volts with the engine off, and around 14 volts with the engine running).

(first one I found) of the kind of device I'm talking about (though everyone who works on their own car really does need a multimeter too - this is just a very convenient way to monitor your charging / battery system).

Everything sounds consistent with a typical bad alternator issue, though you won't know until you check the voltages...

 

I read the battery charge histogram on my Autophix 5900.