This battery lasted 8 years 1 Month. It failed. I charged with CTEK, next morning just switch on and switch on all lights, voltage dropped fast from 12.86V to 11.5, hear gassing, relay click switch off, no engine light or so.
Battery bust for sure. Charge again just to keep some charge in it.
New battery ordered previous day(Accepted old age).

Just want to make sure about the procedure replacing the battery.
The W204 manual say:
1- to disconnect NEG(Earth) 1st, then disconnect Pos.
2- to remove clamp.
3- Remove battery.
4- Replace battery.
5- Tighten clamp.
6- Connect Pos.
7- Connect Neg(Earth) last.

Question:
After doing this what can I expect to be not fuctioning and will needs a reset-?
I have read about using a booster in parralel while replacing battery as to not loose power to electronics on Youtube(The guy was quite serious about this method.)

I have asked the local auto electrician which is clued up I would say and they said no need on this car to use parrallel power. Another shop also working on Mercdeses also confirmed this.
Have not asked the dealer, far away in any case.

Curious. Was the batt maintenance free or did you have to add water occasionally?

The batt looks maintanance free, I cant see any places to add water. When charged by the CTEK MSX 3.8 I can hear gassing inside the battery, so I assume its lead acid type, it has a vent pype connected on the side.

Printed on Battery.
A 000 982 22 08
12V 84Ah 700Aen
Q001 ZGS2

Removed the stickers and found the filler caps. The cells are covered with water. All the cells except one gasses easily when charged.

Question:
I just want to know if this terminal remove method is safe as described in manual.

Problem Solved:
Battery replaced with Varta F19 Silver Dynamic 12V-85Ah-800A(EU). Car started like never before since new. I think my rarely nonstart problem will be gone as well as that it never started after same predictable turns as all other vehicles I owned. Think orginal battery was "partially" faulty all these years, since 1st service I would say.

Sleep mode bonnet open.
Remove cover
Remove NEG-Earth.
Alarm went off....let it run till silent.
Remove POS.
Remove clamp.
Remove battery disconnect vent.
Replace battery connect vent.
Reposition POS.
Reposition NEG.
Alarm went off, cleared immediately with key.
Car started without problems, no messages etc.
Charge new battery further with CTEK 3.8.

....Have not checked mirrors, windows ot sunroof, radio yet.

These cars should have a AGM (Absorbed Glass Mat) battery fitted. .http://batteryuniversity.com/learn/a..._glass_mat_agm

My original battery in my 2008 was still going but I just replaced it yesterday with a new North Star (same as Odyssey) AGM unit for peace of mind.


I can't believe the OG battery lasted 8 years and still has some life left.


I bought some $10 thing that has a 9-volt battery and you plug into your 12v receptacle and it will save your car's pre sets so you don't have to reset everything after swapping your battery.

The original Varta battery on my 2008 C350 just failed after 9yrs 3 months. Testing of the old battery showed that the Cold Cranking Amps (CCA) decreased from 700 to 568 and voltage 13.0 volts. I have since replaced the Varta with a Walmart Everstart MAXX battery rated at 790 CCA with 3yr full replacement and 5yrs total warranty. The new Everstart battery cost CAN $138.95 plus tax whereas a MB standard Varta replacement from the local CAN Mercedes Dealer is CAN $249.99 plus tax.


My 2008 C350 was without power for more than 24hrs during the removal and installation process. After installation of the new Everstart battery most previous settings including the correct time were automatically restored. I will find out over the next week if any settings need to be reset.


JR

These cars prefer a Absorbed Glass Mat ( AGM) battery because of the high power demand. I hope your Walmart is one.

My EverStart is not an AGM battery but I have used it with great results in my 2002 MB C320 wagon since 2012 so I am hopeful I will have similar results with my 2008 C350. Everlast battreies are made for Walmart by the same company that makes the OE Varta battery for high performance cars and specifically for the Canadian winters.


Hopefully my 3yr replacement warranty will kick in and give me at least 5-6 yrs with the EverStart.


Thanks for the AGM recommendation.


JR

I checked again and the Everlast MAXX 94R H7 battery that I just installed is an AGM battery. This is great news.


Check out this link.
https://www.walmart.com/ip/Platinum-...ttery/40685088


JR