Battery Replacement

[MTI]

Tools:

13mm socket with extension
13mm open end wrench
Vice Grips

(Optional)
Paint brush
Baking Soda
Paper cup
Towel

First, make sure you have the CODE card for the radio if you still have the OEM radio. The dealership has a charging system that is hooked up to the jumper terminals under the hood to keep the CODE, radio stations, windows buttons and dash clock going.

Second, clean out the crap from the trunk.

http://community.190revolution.net/gallery/data/515/medium/W202_Trunk.JPG

Lift out the trunk carpet

http://community.190revolution.net/gallery/data/515/medium/W202_Trunk_Cover.JPG

http://community.190revolution.net/gallery/data/515/medium/W202_Battery.JPG

Use the 13mm socket and extension to undo the battery hold down.

http://community.190revolution.net/gallery/data/515/medium/W202_Unbolt_Holder.JPG

Use the socket to loosen the NEG termimal.

http://community.190revolution.net/gallery/data/515/medium/W202_Unbolt_Neg.JPG

There's not enough clearance to use the socket on the POS terminal, so use the open wrench. I used a vice grip to keep the cable from twisting and rotating.

http://community.190revolution.net/gallery/data/515/medium/W202_Unbolt_Pos.JPG

With the terminals clear, lift up the battery handles and pull it out. Warning, it's very heavy and could possibly have dried chemicals underneath, so be careful.

http://community.190revolution.net/gallery/data/515/medium/W202_Battery_Handles.JPG

As you can see, the battery left some chemical residue, which includes battery acid.

http://community.190revolution.net/gallery/data/515/medium/W202_Battery_Tray.JPG

First, use a shop vac to clean it out.

http://community.190revolution.net/gallery/data/515/medium/V202_Battery_Vac.JPG

For what ever's left, you need to neutralize the acid. With some baking powder and water, mix up a thick paste and use a paint brush to apply it to the battery tray. The soda will neutralize the acid residue.

http://community.190revolution.net/gallery/data/515/medium/W202_Soda_Neutral.JPG

Wipe out the area with a clean towel.

Installation is the reverse of removal.

When replacing the battery, make sure you hook up the battery vent tube. The tube routes combustible gas from the batter to outside the car.

http://community.190revolution.net/gallery/data/515/medium/W202_Battery_Vent.JPG

The battery I purchased didn't have the vent tube outlet in the same position as the OEM battery, so with some tubing, I re-routed it to fit.

http://community.190revolution.net/gallery/data/515/medium/W202_Interstate_Vent.JPG

http://community.190revolution.net/gallery/data/515/medium/W202_Interstate_Vent_3.JPG

http://community.190revolution.net/gallery/data/515/medium/W202_Battery_Done.JPG

[xvvvz]

Nice writeup! One thing you mentioned briefly but that might need an extra note is that you will most likely need to re-synchronize the windows and sunroof. Instructions are in the owners manual but it is pretty simple. If you don't do this, the windows and/or sunroof will often not fully open/close unless you press the button multiple times.

[Renn 208]

Nice write up and great pictures!

[DynoXG]

Awesome DIY! Great pictures and nice close ups.

[timmyj51]

But you replaced the MB OEM battery with a crappy Interstate!
Consumer Reports rates that brand as virtually the WORST
battery!

[DynoXG]

Originally posted by timmyj51
But you replaced the MB OEM battery with a crappy Interstate!
Consumer Reports rates that brand as virtually the WORST
battery!

I put an interstate in a Firebird and never had any problems.

[MTI]

When I checked the dealership, it turned out that the dealer was an Interstate distributor.

Remember too, that it's not Mercedes that makes the batteries, just like Mercedes does not make shocks, struts, CD changers and other components. At least in the US, Mercedes automotive batteries were made by Johnson Controls, which also makes/made the batteries labeled as:

AutoZone
Costco
Pep Boys
Sears
WalMart
Interstate

[DynoXG]

Originally posted by MTI
When I checked the dealership, it turned out that the dealer was an Interstate distributor.

Remember too, that it's not Mercedes that makes the batteries, just like Mercedes does not make shocks, struts, CD changers and other components. At least in the US, Mercedes automotive batteries were made by Johnson Controls, which also makes/made the batteries labeled as:

AutoZone
Costco
Pep Boys
Sears
WalMart
Interstate

You really know your batteries. Did you get the pm I sent you?

[xvvvz]

>>AutoZone<<

Yep. I was noticing how your battery was very similar to mine.

If people want the same battery that came with their car and have an OReilly part store near them, they sell (or at least did a few months ago) the same battery but it comes with a black case instead of a white one (same built in handles and everything).

Since we are talking about batteries, remember to always check the date code. Buy the freshest one you can find (usually at the back of the rack) and never one older than 3 months old. Here is how to decipher the code:

http://www.allpar.com/fix/batteries.html

[Cru328prod]

I know this might be a stupied question but when should you replace the batteries in the car?

[timmyj51]

General rule of thumb: every five years.

[Cru328prod]

Originally posted by timmyj51
General rule of thumb: every five years.

hmmm might buy a optima yellow top

[timmyj51]

Originally posted by Cru328prod
hmmm might buy a optima yellow top



Friend had one of those in his car and it conked out after
four years.

[DynoXG]

Originally posted by timmyj51
Friend had one of those in his car and it conked out after
four years.

Yeah, my friend also had a yellow top and we had to keep replacing it. Total of about 4 times, then he just gave up on it. I had to pick him up everytime it went bad.

[DRM]

does anyone know which optima yellow top model you use for the w202?

heard nothing but good reviews from people at car audio places who use them in their cars.