E53 4.4 N62 2004 no electricity

[raksike]

I have owned this car now for five years. On every spring and every fall I have had this kind of issue, that suddenly, during normal driving, the car seem to lose voltage in the battery. It starts to turn on ABS lights and all other different lights and warnings until the car just stalls. When trying to restart it, then it behaves like the battery would be dead. Since now, it helped when you jump started the car by using the plus and minus which are located under the hood. Basically just connect the wires, even 5 sec worked and then it starts and works as it should until next time which happens usually after every 6 months. Also when the battery would be dead, then it would not have worked since with only connecting the wires from other car and right away removing them. It is really odd, but it has been like this all the time from the time I have owned the car, around 5 years.
Today morning, I started the car for warming it up due to cold weather, everything was nice, but after 5 minutes it started the circus, until it died completely. But now the jumpstarting does not help anymore as it used to, it seems that it runs only that long, as you charged the battery when jumpstarting the car with one other car.

I checked the connections in the trunk and the battery connections and everything seems ok. Are there somewhere some kind of typical power cable connection points which I could check besides the trunk?