e class 211 03 plate - Battery problems

[rogerg]

hi is anyone aware of a fault which causes battery to show that electrical consumers are turned off.this has happened a few times with no problem after car had started,but yesterday car unlocked ok but key wont turn, couldnt get out of park .car eventually started after quick jump start. e class 211 03 plate thanks

 

[drmw]

consumer electrics offline mean the battery is below a certain voltage - if it then wouldn't start without jumping, then odds on the battery is stuffed

 

[kay187]

I had similar recent issues and its looking like a duff alternator, car in garage so won't know for sure till later.

I would recommend checking the voltage on the batteries (front/back) both when car is off and on to determine if its your batteries or the alternator.

Good luck:neutral:

 

[DY2]

As above - check both batterys with a voltmeter.
With the engine off, you should have about 12.5v at the terminals
And with the engine on, you should have a reading around 14.0v

 

[Vigilant]

I had the same problem on my 2003 e320 cdi. There is a further battery under the air con unit on the left hand side under the bonnet. To replace it is about the same size as a motorbike battery and cost approx £60 from main dealer.

Hope this helps


Vig

 

[television]

The first thing to check on a 211 is to see if the update applies to their car, one also has to remember that on cars that do not get used that much the rear battery should have a good charge once a month. The design had not been thought through that well, every time you stop and start one the current while going to sleep is quite high

 

[rogerg]

thanks for ideas everyone ,think it must be pointing to brake battery or alternator as main battery is new .will check voltages cheers

 

[whitenemesis]

thanks for ideas everyone ,think it must be pointing to brake battery or alternator as main battery is new .will check voltages cheers

Everything runs off the main battery (in the boot) the axillary battery in the engine bay is only used if the main battery is low on charge.

STAR diagnosis should reveal if the alternator isn't charging correctly

 

[rogerg]

problems with consumer electrics

just an update ,changed small battery in bonnet.touch wood all seems well ,working it out that original battery must have been 9 years old!!!!!!!!! thanks all