Mixxit

Hi all! I've had a 2006 E500 for a few years now. Love the car!

Recently I've been getting the red Visit Workshop message with the battery picture. Obviously I need a new battery. After I clear the message, the display says that "convenience functions are disabled until the battery charges". However, I'm not sure which battery it's asking me to replace. I've been told that there are 3 batteries in this car. The main battery under the hood, the aux battery near the passenger wheel well, and an electronics battery under the rear seat. From what I'm told, the one under the seat runs the convenience stuff; so is it that one?

How do I tell which battery is low and what do I need to know about replacing it?

Thanks for any input you can provide. I just can't see paying dealer prices to replace a battery. Love the forum. It's provided me lots of invaluable stuff over the past couple of years.

PortAxePlayer1

Hey

Ok so first thing, there's 2 Batteries in your car, one in the trunk, which is your primary, that's the one that powers all the electronics stuff then there's the Aux battery located under the bonnet upfront,

The third battery you mentioned under the rear seat was present only in the W210 E-Class from 1996 till 2002, and back then it was the only battery present.

Now, usually when you get the Red "Visit Workshop" it's usually the aux battery because it can power the SBC system in case of low voltage from the main.

Check your voltage reading before starting the car, put the key in the ignition and turn it once, set the dashboard to the speed display and press the reset button 3 times in rapid succession, it will display the main battery's voltage.
It SHOULD be above 12V if the battery is in good health.

Mixxit

Thanks for the info! I just checked it and it was showing 12V exactly. That was after sitting outside in the 10 degree cold for a few hours so my guess is that it's good. So if it's the aux, where can I get one, and is there anything I need to know about replacing it? Once I do, will the message go away or do I need to reset it some how? Thanks for the help!

jimbo1763

https://mbworld.org/forums/e-class-w...-workshop.html

See if this helps.

Green E-300 DT

Read all 280 plus messages and go buy the correct battery and fix it yourself.

If I could do it, so can you. Save yourself a ton of dinero. It is a really simple job!



Derrel

PortAxePlayer1

I can't really refer you to anywhere where you can get it cause i don't live in the US :p But it's a pretty straightforward job, the message will go by itself after turning the car on once or twice

Frasmat

I got my replacement aux battery from Autozone. Check in the motorcycle battery section for the size 14-BS. It's a simple replacement. You should have no problems with the install

Taylor-Made'90

Between AutoZone and Walmart, you can replace both batteries cheaper than replacing the main one at the stealership..

Green E-300 DT

While shopping, before I decided to have my parts friend see what he could do for me for
the little one up front, I was at Wallymart. The back battery (the monster) was less than
$100 not including tax and the little one for up front was much less of course.
Perhaps $69 if I recall correctly?

But I didn't need the monster, as I think it has been replaced before.
But the little Fiamm was the original and has a build date of 44 04!
It was about time wouldn't you agree?

It is such an easy job, you MUST DO IT YOURSELF, unless you've got money to waste?
And while you're at it, you can replace the cabin filter which is right there also.

How do they say . . killing two birds with one stone?

How much will you save just in labor alone by NOT having the stealership do that little job?

Where can a person buy that filter at a reasonable price?



Derrel

dtrentr

Napa stocks the Mann OE replacement and sometimes they have them for 25% off.

Mixxit

Sorry I'm just now getting back to everyone. I've finally read the entire other thread that Green posted and I'm gonna swap this thing tomorrow. I'm going with the Sears BS-14 battery. Just to confirm, this is what I'm gonna do:

- Open hood
- Remove cabin air filter housing.
- Disconnect negative lead from main battery in trunk (I've never seen this battery but I assume it's easy to get to?)
- Insulate negative lead so it doesn't touch anything.
- Disconnect negative lead of aux battery.
- Disconnect positive lead of aux battery.
- Remove old battery.
- Insert new battery.
- Connect negative lead of aux battery.
- Connect positive lead of aux battery.
- Connect negative lead of main battery.
- Start car and open and close windows and sunroof. Turn wheel all the way to the right, then left.
- Rejoice?

That should be it, right?

Before I do any of this, I'm going to fill the new battery per the instructions and charge it for 2-4 hours making sure that I'm showing over 12V before installing.

Sound about right? Anything else I should know or worry about?

Thanks to everyone for their help so far!

Green E-300 DT

Here is all that you need to do:

- Open hood
- Remove cabin air filter housing. Only the top, not the entire housing.
- Disconnect negative lead from main battery in trunk (I've never seen this battery but I assume it's easy to get to?) Skip this step entirely. It is not easy to get to and this step in not necessary!
- Insulate negative lead so it doesn't touch anything. Do NOT DO THIS STEP.
- Disconnect negative lead of aux battery. Keep both of these leads from touching anything including each other.
- Disconnect positive lead of aux battery. Keep both of these leads from touching anything including each other.
- Remove old battery.
- Insert new battery.
- Connect negative lead of aux battery.
- Connect positive lead of aux battery.
- Connect negative lead of main battery. You did not disconnect this main battery, so this step is not necessary either

<< - Start car and open and close windows and sunroof. Turn wheel all the way to the right, then left. >> Not necessary as you did not disconnect the main battery, remember?

- Rejoice? YES. Isn't it nice to save a little dinero?

That should be it, right? Yes again.

Before I do any of this, I'm going to fill the new battery per the instructions and charge it for 2-4 hours making sure that I'm showing over 12V before installing.
There are batteries that you can get that are already filled, so this would not be necessary.

Sound about right? Anything else I should know or worry about? No.

By skipping some of these steps, you will not only save time, but you will not have to worry about such things
as the radio perhaps loosing its code like it was removed by a thief and the others you have mentioned.

I bought an already filled battery and it did not need charging.
BTW, be careful when you charge your new aux. battery as these little batteries are basically motorcycle
batteries and do not have that much capacity and will not take too many charging amps.
I simply removed and replaced the bad little aux. battery with the new one and that was it.
Nothing could be easier, believe me. You will agree when you are finished.

HTHs and good luck.



Derrel

Mixxit

Thanks Derrel! Much appreciated!

Green E-300 DT

Let us know how everything turns out?



Derrel