C Class battery replacement

[m500dpp]

My C250CDi w204 battery is showing signs of it's 5 year age and I will probably replace it before winter. Have done this on many cars but none with such complex electronics.

Can I simply disconnect the old battery and swap it over, and if so will the car loose any settings? Is it necesary to rig up an auxiliary reply whilst the battery is disconnected.

Sorry to ask such a basic question by I want to get this right!!!!

 

[markjay]

My 2006 w203 is still on its original battery - 9 years old now.

This is not unusual - original MB batteries (Varta) can last for a very long time.

Of course it is perfectly possible that your battery is indeed in need of replacement, but my point is that the battery should not be condemned automatically just because of its age.

 

[markjay]

As for replacing it, you could use a battery memory device if you wish, but there is no need - the battery can simply be disconnected and reconnected.

Just make sure that the ignition if switched off and the key removed, and that the car is not locked.

The ECU and TCU do have adaptive memory, but these will renew themselves very quickly.

 

[m500dpp]

Thanks Mark, I checked the voltage yesterday which at 12.1 volts I felt was a bit on the low side. A standard spare battery was showing 12.75. I have put it on my Optimate charger overnight - it may be because it hasnt been used for a few days.

I have rigged a fly lead to the battery with a socket so I can easily plug in my charger, so keeping it charged when I am not using it . Will see how it goes......

Interestingly I have just bought an X Trail, which is 11 years old. Judging by the screw caps on the battery and japanese writing I think it is the original, this was showing 12.4 volts but has been in more regular use.

 

[rifiki]

I changed the the original battery on my 05 CLK a few months ago. Just replace the old with new battery, the time clock set it's self, job done. The battery is now in my Ponton.

 

[Dave Richardson]

I changed the battery in my CL 203 just a few weeks ago, just changed it without any problems, the ESP light came on but cleared itself almost straight away & I had to re set the clock.

I bought a Duracell battery from Europarts which cost approx £100

Nothing else at all.