Hi All,

I have some problem on my W221 S500. The multifuction display always show the message "Charge Battery" and I could not remove this message. I did change the battery but the message still show then I check the voltage on the battery while the engine is running. The battery voltage is 14V. Now I think the battery and alternator is ok. Could you please advise where should I check for this problem?

I bring my car to check with the Star Diagnostic, there is no error code on the engine and also the ICS.

Please see more detail on the attached pictures.

Thanks for your support.
Korrwit

 

These are serious exteriour temperatures in May btw , but could be your accesoiry battery that has died ..for your MY not sure where it is located as its different ie smaller then
for the older models, where it lives in the trunk behind the largest vertical panel .
Have you driven it for a while to charge it ?Looking at the odometer your car is almost brand new??

 

Thanks Marthyh. This car is brand new, we used it just 2-3 months. I did check the accessory battery in the trunk, there is no this battery... This car has only 1 battery in the front of car and I changed the battery already.

 

You should have a smaller one for accessoiries as well ,not sure where it lives though..hopefully another member or expert rings in very soon ..

 

You may have drained the the accessory (or consumer battery). There is a 2md battery in the trunk. That battery can be charged from the Engine compartment. No need to remove truno panels etc to ger it the battery leads.

 

I opened the trunk and remove the black panel. I saw only the space to put the battery but there is no this battery. And also I drive the car around 30min to 1hr to charge the consumer battery but the message still show. any idea?

PS. on the space between trunk and rear seat, there is no battery and battery cable. I will get the picture today and post again.

PS2. My friend's car : S350 W221. This car also does not have this consumer battery. Is it possible that it is in another place?

 

Korrawitt,

You'll have to attach a photo of the trunk panel that you removed. There is actually 3 batteries in the W221. Starter, Consumer and a 3rd battery under the driver side dash.

I've attached a photo for you, again, this is from another member who supplied the jpeg.

Don't charge it by driving around. Get a good battery charger instead (I use a CTEK brand, same one that MB sells, just without the MB "sticker" on the charger)..

 

I'm quoting the below from another member (forgot his user name though) on this forum about charging the Consumer battery..:

"You can charge your trunk battery by hooking it up under the hood.

On the passenger side just left of the starter battery there is a black plastic box. Remove the cover and you will see the power points for the rear trunk mounted battery. The tall terminal, the one near the front, is the positive terminal. Connect your positive lead there and hook the negative lead to the negative terminal on the starter battery. If you want to charge the starter battery just move your positive lead six inches to the positive battery terminal. Hope this make sense."

See photo.. hope that helps you

 

you can find more details in the attached pictures.

Is it possible that the problem is from the battery under the driver side dash?

 

I jumped the external battery to the terminal from your advice. The result still the same. There is the message still show on the multidisplay. Please see the attached pic.

 

Have you resolved this issue? From the pic you provided it looks like you are missing a battery in the trunk all together but I could be wrong. With the engine off can you power up your command? It should come on with no problem, if not then its the one in the trunk. Let us know. Also what year is your car?

 

Indeed if it is a facelift (not hybrid) W221, it does not have the consumer battery at the trunk.

Have you had the car diagnosed?

Does the alternator really charge the battery?

 

Korrawitt.. Any update on your situAtion? Curious to find out what happened..

Do you have a multi-meter? I'm curious if there is any voltage from those two terminals you clipped onto.

Popo here... Has a good point comand should not work if your vehicle is turned off and you don't have a consumer battery.

Hope you figured it out..!

 

korawitt are you sure you don't have a consumer battery on your rear? better check if your car is really a W221, the front battery is meant for starter motor only so if you do not have any consumer battery i don't think yours is a W221, to access the rear battery you need to take out several nuts and bolts, not easy and takes a long time. your search for the second battery sounds strange and even more mysterious if it is not there.

You mentioned your car is still new, then send it to the dealership where you bought it, either demand for a change unit or have the trouble diagnose and rectify by the dealer

 

accessories battery is the bigger one, smaller one is for starter

 

Oh No don;t play with fire or you might get burn, go get a pro to do it for you please, or send it to a dealer where you bought it,
i'm sure your still covered by warranty

 

What finally happened?
i met same chatge battery and battery not charged problems. can not remove that and left buttons on steering wheels can not help with that,

Even local benz official dealer service can not find the reason.

Pls anybody help me

 

I have same problem with this! Anyone solve this problem pls let me know!

 

I guess it is a W221. From the previous posts you can see that it makes a big difference if the car is a facelift 221 or a pre-facelift 221, better to tell more details.

Check the alternator too.

 

I had the starter battery changed in my 08 a couple weeks before the car was totaled. Now that I have the 10 I noticed the starter battery is much bigger.. Did they indeed ditch the battery in the trunk on the facelift and go to one battery? If so it almost seems like they downgraded.. I like the idea of having two batteries better.

 

I think MB dropped the 2nd battery in the 2008-2009 models.

My brothers 09' has the same sized electronics battery under his hood as I have in my 07' trunk.

 

Yeah from what I have read MB dropped the battery in 2010. So 09 would be the last year with the dual battery. Having owned an 08 and now quickly gotten into a 10 I am starting to wonder if the quality went up or down..?

 

Hello I have exact same problem guys, my screen show same message and is no way to do something because left buttons on the steering whel don't work, I got new battery from dealer, and my car is 09 221.186 and comes only with one battery in front nothing in the trunk only small one 12V 1.2 A under dash also new in my case.

Please any help???

It's red Message "battery not charged"
And after disconnected battery for 30 min I have white message "Charge battery"

In my case it's brand new battery from mercedes.

 

Replace Front SAM module (поменял, его прошить, привязать к машине)
Must be programmed to the car

 

Your post came in very useful.