discussion F30 320d Volatge irregular

[Danielb1]

Hi everyone,

I recently replaced my car battery, but after a few weeks, I noticed that the Stop/Start function stopped working. I called Atlas Battery to check the battery, and they found that it wasn't being charged, so they replaced it without any issues.

Later that week, I took the vehicle to a local auto electrician to check the alternator. They removed the alternator and serviced it. When measured with a multimeter, we were getting about 14V. I was advised to use the car to allow the battery to pick up a charge.

Today, I plugged in my OBD diagnostic tool and drove to work while measuring the voltage. I noticed that the voltage was very irregular, ranging from a minimum of 12.3V to a maximum of 13.6V.

I believe this irregular voltage is the reason why the Stop/Start function isn't working.

Is my alternator still faulty, or is it a battery issue? I would really appreciate your assistance. I’m located in Durban and my number is 081 574 1164

Thanks!

 

[Solo Man]

Normally the alternator should charge at least about 14.2v but i have seen as high as 14.7v. I recently saw a post about how modern BMW's batteries are regulated so that when the car decelerates the battery gets extra charge. Browse this forum. I think your alternator is at fault here. Also, let it idle for a few minutes while you check the charge rate. Found on a previous 1 series i had that the charge would go down to below 12v for a split second then go back up to 14.2v. Regulator was kaput.

 

[Clint@MMS AUTO]

Did you register/code the new Battery to the car once it was fitted?

 

[Mytfine]

How may k's is your daily drive ?