Battery issue

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Bigrichw

Active Member
Joined
May 25, 2016
Messages
239
Location
Nottingham
Car
CLS 55
Looks like a new battery is required on the CLS55 - over the past couple of days its been throwing up a battery protection message in the mornings, didnt think anything of it - but today, she dead - no life..
Is it the main battery in the boot that needs changing?
 
You need to firstly have the main battery tested to see if its holding a charge or defective, if your in a recovery service they will usually do this test for you....i think battery should be in the boot but i am sure others will confirm.
 
Sorted. New battery fitted. Thats a battery and a half


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Sorted. New battery fitted. Thats a battery and a half


Sent from my iPhone using Tapatalk

Check the condition of the one under the pollen filter on the passenger side bulkhead Rich. If that is going down it will draw power from the main battery.

They are about £75 from MB or ECP do one for about £50.
 
Not sure that's correct ^^^^

The AUX battery is out of circuit until called on by a low system battery voltage so won't impact on general charge levels but agree it should be checked and probably replaced if original.

A new AUX battery did nothing to improve i.e. reduce the number of battery messages I got in the CLS. Only thing that worked was to put the car on trickle charge every couple of weeks
 
Not sure that's correct ^^^^

The AUX battery is out of circuit until called on by a low system battery voltage so won't impact on general charge levels but agree it should be checked and probably replaced if original.

A new AUX battery did nothing to improve i.e. reduce the number of battery messages I got in the CLS. Only thing that worked was to put the car on trickle charge every couple of weeks

I am sure you are correct on this Peter, as you I have similar issues.
If the battery under the bonnet is date stamped older than four years, replace it as a matter of course.
 
I am sure you are correct on this Peter, as you I have similar issues.
If the battery under the bonnet is date stamped older than four years, replace it as a matter of course.

my CLS55's factory fitted main battery lasted 7.5 years. Car was on original small bonnet battery when I sold the car at 10 years old.
 
I guess journey types and typical usage has a big effect on battery life?
 
Check your new battery over the next 5 days or so, if it starts to lose voltage then it's alternator time.......ouch

Jules
 
I managed to jump start it, and drove it around for a few miles, which charged the battery, so dont see it being an alternator issue. I will monitor the situation, but so far so good.
 
Not sure that's correct ^^^^

The AUX battery is out of circuit until called on by a low system battery voltage so won't impact on general charge levels but agree it should be checked and probably replaced if original.

A new AUX battery did nothing to improve i.e. reduce the number of battery messages I got in the CLS. Only thing that worked was to put the car on trickle charge every couple of weeks

I am sure you are correct on this Peter, as you I have similar issues.
If the battery under the bonnet is date stamped older than four years, replace it as a matter of course.

Fair enough guys. That was my understanding which appears wrong. Sorry for giving wrong info Rich.:fail
 
Did you get the old battery tested before you changed it? its a really easy check red or green result....you need to have done this to eliminate Alternator issues as highlighted by Jules above...

I managed to jump start it, and drove it around for a few miles, which charged the battery, so dont see it being an alternator issue. I will monitor the situation, but so far so good.
 
Everything working as normal now. Thanks chaps


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