Hello

I have some amazing problem with my E60 252I 2004 year

about a weak ago I was driving my car and unfortunately all the warning lights came out and after 2 second car stalled, also I was unable to start him. somehow I got my car at home and I measured battery voltage and it was 11.2 V. after many research I replace my VR brushes, I charged my battery and measured my car voltage it was 14.2 V (stereo, A/C compressor and headlights was on). but unfortunately after 2 days the same problem happened again after this when was trying to remove my car battery I mention that my positive wire was loosen, and battery was also dead can the loosen positive wire cause the same problem??

I charged my battery again and using contact spray clean my cars positive and negative wires, after this started my car and charging was pretty good 14.5 V. after this I drive my car about two hour and measure my voltage and it was playing from 13.0 V to 14.0V, is it normal behavior? can this problem caused by bad alternator or VR regulator???

 

Could be the loose connection was your problem. Give it a week.

 

Of course the loose battery cable could have been the problem.

When the clamp is loose the resistance between the clamp and the battery terminal is dramatically increased, blocking the charging of the battery.

As the previous poster suggested, fully charge the battery and then monitor it for a week. If you know how to use a digital multimeter you can measure the voltage after the battery as rested a few hours each day to monitor progress.

Use caution in tightening the battery clamp bolt (don't put too much tightening force on it) as the clamp itself is constructed out of stainless steel and if you strip the bolt thread you will have to buy a new battery cable to the tune of hundreds of dollars.

 

Today i have another strange situation during my battery monitoring processe i notice that voltage was very low about 11.8 V (of course car was started) , i was at parking near my university and was going to home, i get panicked and began thinking what to do to reach home safely ) after 2 or 3 minutes i opened my hood and disconnect VR wiring after this i measure my battery voltage ant is was wary stable 14.02 V. Now i have one question: it is clear that this problem is caused by bad VR regulator, but what will happened if i do not buy a new regulator? Now my charging level is pretty good and why i need new regulator??

 

You are seeing signs of a regulator going out. It could be fine now but bad tomorrow. Driving with a bad regulator can cause many issues that can empty your pocket. Battery being over charged means that systems can fry (their are lot of modules and sensors that can fry and be very costly especially your ECU). Battery not getting the correct charge can cause the battery to die and you have to purchase a regulator/alternator and battery. In the end it is up to you how you want to handle it. Personally I would replace it immediately and hope no underlined damage has been done.

 

thanks for replay I will purchase and change it with new one

 

"Despite having a battery drain somewhere (which I believe I do - did not yet tested what's the consumption after sleep), "

You need to test for current draw after the car has gone to sleep. Remember that it's also possible to change the behavior of Terminal 30, 15, 30g, and 30g_f with coding. Just make sure they are set to turn off within a reasonable amount of time once the key has been removed.