By way of background, I purchased a new 2024 S Class on March 5th. The date of manufacture was Nov 2023. I was of course concerned about the batteries as the car had been on the dealers lot for over a year but was assured by the selling dealer that everything checked out. I left knowing I had a 4 year warranty. Fast forward to early April and I tried to put the electrical system in standby. I received a message that the battery was insufficiently charged to go into standby mode. Hmm, what’s with that. I drive the car almost daily and regularly take it out for an hour or so of freeway driving just because. I did charge the battery once with my NorCo 10 amp charger. Took several hours to come to a full charge. The car is kept in a garage and is locked when not in use. Keys, both of them, are kept in a Faraday box.

I took the car into the local dealer where i was told it shouldn’t take more than a half an hour to check out the charging system and the battery. After waiting an hour and a half ( silly me, I thought they were replacing the battery) I was informed that everything checked out satisfactory. The service writer suggested that the tech advised that I put the car on a battery maintainer if not driven every 24 hours. I loudly voiced my disbelief that a new $140000 car couldn’t sit for more than a day without substantially discharging the battery. It was apparent that the car was not even put on a charger because I received the same insufficient battery warning immediately upon returning home. The only other dealer nearby is an hour and a half away. I really expect that the problem is the battery and a simple replacement will solve the problem. I could simply eat the cost as it would be easier than driving for 3 hours to perhaps get the same response.

The only time I received a low battery warning on the app was when the car went in for PPF. I called the shop and they put in on a charger. At this point I’ll charge it completely once again, drive it for several days and the try putting it into standby again. If that doesn’t work, back to my hometown dealer. It may just be a matter of out lasting them.

 

I think you hit on the head when you said the car sat in the dealer's lot for almost a year.

Putting on a battery maintener if you do not drive in 24 hours is complete and utter BS! My car is a 2019 E450 with the original battery, which when I put in standby mode says 20 weeks. If I put a charger on the battery, it will go to 32 weeks. I often leave the car outside at my friends house, temps in the low 20"s, for 8/10 days at a time when I fly out west to ski. I do not put it in standby mode - I want all the anti theft provisions fully operational. When I return home no problem with the battery. To be on the safe side, this winter, the battery being 7 years old, I plan to replace it.

If your dealer is correct, then no Mercedes could ever be left at an airport. Again complete BS.

You may have to get regional MB involved: it seems to me you need a new battery.

Hope this helps

Addition: Assuming the battery is either an H7 or H8, you can get it replaced at Walmart for $179 which includes installation. The battery comes with a no condition 4 year warranty: if at any time during the 4 years something happens, Walmart replaces the battery - no questions asked.

 

My 2024 S580 just sat for 10 days and fired right up.

The issue is the 12V battery, not the 48V battery. It needs a new 12V battery.

 

Yup bad battery, since you said you will be willing to just eat the cost I see no reason they refuse to replace it for you.

 

That can't be true... We left all of our cars for 33 days from Dec through 1st week of Jan. We came back and each one of them started immediately including the GLS with the same 48V system u have in your W223.

As others said, battery maintainer when you do not drive in 24 hours is just BS.

 

MB has had issues with this before, its a bad 12V battery. They often will try and tell people the car needs to sit on a battery tender...

 

It’s your Key Fobs and the proximity to the car!!! Put your keys in a faraday box or a faraday cover. If your key is close by, your car will continue to send a signal to it-looking for a response back and in-turn it will open and close the door handles. This WILL drain your battery very quickly.

 

I battled this with Mercedes for 2 years until I went to a reputable MB dealer. They replaced the battery because of polarity issue and solved the problem. Mercedes service is really bad here in Germany and I have been dealing with them from one problem to another. Right now, I battled with them to return my YouTube app they removed without my consent and was able to win by them giving a 600 euros voucher after 3 long months of painful back and forth. My issue now is they said if I purchase a video streaming subscription, the streaming app will automatically load. Guess what, the YouTube app is there but no video stream portal app. So keep in mind, that once your subscription is up, they will automatically remove YouTube app now since it is part of the Video Streaming package.

 

no doubt this is a possible cause but the actual solution to the problem is to replace the defective battery.

 

I have my key fobs relatively near my car: the only battery that drains is the one in the key fob - my 12 volt battery as I posted above is fine.

 

I had similar issues with my MY23 a couple months ago. Took to local dealer, and they said it needed a battery software update. Issue solved. No more 12v battery low, or critically low messages in car and in app…..

 

My keys are hanging right inside the garage door. Did that for 10 days no issues. Thats not necessary unless the 12v battery is faulty

 

Update. I put the car on my 10 amp charger overnight. It’s a shame the dealer didn’t do this. The car easily went into standby mode after being charged. The display advised I had 5 weeks of standby wherein I could start the car without difficulty. That’s more than adequate for my purposes. Nevertheless, it bears watching.

 

You have a bad battery.

My battery is over six year's old. After charging, when I put it in standby mode, I have 30 weeks.

Others have reported with a new battery that when in standby mode they get over 40 weeks.

 

Actually I had 52 weeks on a C238 2019 E coupe (family member's, as their battery ages I doubt I will see those numbers again).

So OP, is the battery fully charged?

 

Hmm, I’m disappointed. I’ll charge it again this afternoon and see what I get. Sounds like I need to have a talk with my local dealer.

 

The 2019 coupe doesn't have a 48V mild hybrid system though can't really compare that way, as the 12V needs to charge the 48V (when ignition on) via voltage converter, or does the alternator do that? Can someone confirm please?

 

This is how to check the 48V battery charge level: https://mbworld.org/forums/glb-class...rge-level.html

Please report back your findings (level).

You can also check your 12V battery charge level in that menu, report that info back as well.

 

Well, after more than 20 attempts I can’t get the workshop menu to display. When I press home the classic display comes up again. Perhaps Mercedes changed the procedure for accessing the workshop menu in the 2024’s? I’m open to any suggestions. Anyone with a 2024 model year successful in accessing the workshop menu using the technique referred to in the link above?

 

A few things, doors closed, trunk closed, hood closed, windows closed, key in marked spot, ignition in position 1, screen has to show trip and odometer, here try this thread, there are different videos: https://mbworld.org/forums/w213-amg/...e-b-reset.html

 

After reading your post several times and additional attempts to pull up the workshop menu, I finally noticed the words “key in marked spot”. Does that mean the key must be in the cupholder slot or somewhere other than my pocket?

 

It is not a must but apparently did help another forum member, the marked spot has a key symbol, I can't remember where it is in the W223 though.

 

Oh it might be in the cupholder area: https://forums.mbclub.co.uk/data/att...ash=gAsCb-GvLp

 

Back to the garage. I’d sure like to get a screen shot or two before I call the service advisor.

 

What screenshot are you requesting for? Let me see if I can find it for you.