Help! Voltage Issue - Runs low
Thread Starter
Member
Joined: Jul 2012
Posts: 111
Likes: 5
From: OC CA
2012 CLS 63, 2013 Gallardo LP550
Help! Voltage Issue - Runs low
Posted this in the CLS forum but also posting here since it has more members and chassis is the basically the same...
Hope some members with either an obd2 scanner or a cigarette socket battery voltage meter can compare their car with my experience. Been having low battery issues since owning the car new in 2012. It’s been taken in over the years and dealer said it checked out normal. it’s a 2012 CLS63.
When i turn the car on, it registers 14.3 volts or higher. Once i put the car into reverse or forward and give it some gas to start driving, voltage drops down 12.3 to 12.6 volts. It will stay down low like that until i let off be gas to start coasting and/or slow down to brake where it goes back up to 14.3 volts. voltage does not change when AC is turned off or on, or when the stereo is turned off or on. it only changes under movement, it drops on gas input while moving and raises again when coasting or braking.
Can anyone check their car to see how it behaves in comparison? Has anyone have a similar experience and what was the fix?
Hope some members with either an obd2 scanner or a cigarette socket battery voltage meter can compare their car with my experience. Been having low battery issues since owning the car new in 2012. It’s been taken in over the years and dealer said it checked out normal. it’s a 2012 CLS63.
When i turn the car on, it registers 14.3 volts or higher. Once i put the car into reverse or forward and give it some gas to start driving, voltage drops down 12.3 to 12.6 volts. It will stay down low like that until i let off be gas to start coasting and/or slow down to brake where it goes back up to 14.3 volts. voltage does not change when AC is turned off or on, or when the stereo is turned off or on. it only changes under movement, it drops on gas input while moving and raises again when coasting or braking.
Can anyone check their car to see how it behaves in comparison? Has anyone have a similar experience and what was the fix?
Member
Joined: Feb 2017
Posts: 95
Likes: 14
From: austin, tx
2014 E63 Wagon, 1988 BMW M3, 2004 Tacoma
I think that's the intended behavior, all in the name of improving efficiency:
http://www.benzworld.org/forums/w212...-factoids.html
tldr; The alternator isn't always running.
-chris
http://www.benzworld.org/forums/w212...-factoids.html
tldr; The alternator isn't always running.
-chris
