12V Battery: Low
Member
Joined: Mar 2013
Posts: 116
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From: NE Florida
2023 EQS 580
I also heard there was a recent software update regarding the 12v battery drain issue. I understood, and perhaps this is the case with window tinting, that the keys are left in the car. Apparently, the car kept the systems on, as if starting could occur at any moment, and this resulted in draining the 12v battery. Prior to the software update, if you are going to leave the car open, the keys should be stored away from the car.
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From: Iowa
2025 EQS580
There is an associated thread on this. There is a Powertrain Control Unit software update initiated by MB on 4/8/22, which must be performed at the dealer, which addresses (and hopefully fixes) the 12V battery issues some are experiencing. My car is scheduled to have this done on Friday. Suggest everyone contact their dealer for this update. To my knowledge, other marques which experienced similar 12V battery issues had them resolved by a software update as well.
Junior Member
Joined: Apr 2022
Posts: 22
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From: Orange County, CA
EQS 450+
There is an associated thread on this. There is a Powertrain Control Unit software update initiated by MB on 4/8/22, which must be performed at the dealer, which addresses (and hopefully fixes) the 12V battery issues some are experiencing. My car is scheduled to have this done on Friday. Suggest everyone contact their dealer for this update. To my knowledge, other marques which experienced similar 12V battery issues had them resolved by a software update as well.
Junior Member
Joined: Apr 2022
Posts: 22
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From: Orange County, CA
EQS 450+
The red 12v battery icon shows up when I can't unlock the door from the outside. It has happened 3 times since I took delivery of the car late last month. Basically, the door handles retracts, but I cannot pull the door handle to unlock any of the doors. One time I used the manual or emergency key to unlock and get into the car, but can't start due to "12 V On-board Electrical System Service Required" error message on the driver display screen. Hopefully this software patch will do the trick the next time I take the car into the dealership for service.
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I think the previous post was talking about this thread: https://mbworld.org/forums/eqs/83282...ml#post8544556
However, since yours the 12V battery having issues and not the HV battery, I am not sure if it applies to you but bring it up when you are at your service visit in case it does help them solve the issue.
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Junior Member
Joined: Apr 2022
Posts: 22
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From: Orange County, CA
EQS 450+
The dealership where my EQS 450+ is now in for 12v problem says that the software update is not compatible for my vehicle type. The service manager said this. Does this even make sense? sigh!!! ;(
Member
Joined: Jan 2022
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2022 EQS 450+
That's very strange since my 450+ is currently getting the software update. Maybe they're operating on old information? Couldn't hurt to give another dealer a call or contact with the EQS Premier support team via phone
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If you have given this dealership the data I have posted and they still don't know the answer, they are very suspect. I would have them jump start my 12V battery and I would drive to another dealership for service. My dealership knew about this update as soon as I asked them about it, and had no problem downloading it from Germany and installing it in my car this morning. As I said in my previous post, it only took about an hour. I have a 450+ as well. But there should be no difference in the PTCU software for a 450 or a 580. Their reply sounds totally unacceptable.
Junior Member
Joined: Apr 2022
Posts: 22
Likes: 1
From: Orange County, CA
EQS 450+
Junior Member
Joined: Apr 2022
Posts: 22
Likes: 1
From: Orange County, CA
EQS 450+
If you have given this dealership the data I have posted and they still don't know the answer, they are very suspect. I would have them jump start my 12V battery and I would drive to another dealership for service. My dealership knew about this update as soon as I asked them about it, and had no problem downloading it from Germany and installing it in my car this morning. As I said in my previous post, it only took about an hour. I have a 450+ as well. But there should be no difference in the PTCU software for a 450 or a 580. Their reply sounds totally unacceptable.
Junior Member
Joined: Apr 2022
Posts: 22
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From: Orange County, CA
EQS 450+
UPDATE: My EQS 450+ already has that 12V battery software update, according to the service manager at the dealership. They still have NO idea what is causing the doors not to unlock at times (has happened 3 times to me since I bought the car late last month). So they are now hoping to recreate that error message (doors can't unlock and red battery icon lit) by doing an extended test drive over the next few days. Not sure why recreating that error message would give them a better understanding of why this is happening. But that's what they had suggested. If not, the next thing they say they would do is send a request for advice/solution from the "engineers" at MB's Germany headquarters.
Junior Member
Joined: Apr 2022
Posts: 22
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From: Orange County, CA
EQS 450+
Do you guys think it has anything to do with this recall:
https://insideevs.com/news/571928/me...l-ground-wire/
Thanks!
https://insideevs.com/news/571928/me...l-ground-wire/
Thanks!
Banned
Joined: Nov 2023
Posts: 63
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From: Southern
GLC
That's only the answer if you haven't driven your car for a few days or used all of the accessories and lighting. Excessively. I just drove mine for 60 mi on Christmas Eve and woke up on Christmas Day to a car that will not start in a message on my Mercedes app saying my 12 volt system is critically low. I checked the battery with a voltage meter and it's well over 12.8 volts. This is the battery in the boot, not the lithium battery in the front of the car which I believe is what cranks the engine.
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A250e
I find it odd that they recommend to unplug the car. It would seem best to leave it plugged in because there is no way for the car to plug itself in but there is a way for the car to not attempt to charge if it doesn’t think it’s a good idea. I wonder if you can leave the car plugged in but turn the charger off. That way if the charge did go below 50 percent you could use the ChargePoint app (or whatever charger you’re using) to turn the charger back on.
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2023 Mercedes Benz GLC 300 4matic
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From: New England/Florida
2005 SL 500. 2015 S550. 2016 GLE400 2018 S560
No EVs on list and no 2023s on the list as well.
Since they swapped out my original 12v battery on my 2023 EQS 580 sedan the battery has been working as designed, so I can’t complain too much. The car is currently in storage at my house in Florida for the summer and occasionally the 12v battery has gone down to partially charged, but always returns to charged within 24 hours, as designed.
Since they swapped out my original 12v battery on my 2023 EQS 580 sedan the battery has been working as designed, so I can’t complain too much. The car is currently in storage at my house in Florida for the summer and occasionally the 12v battery has gone down to partially charged, but always returns to charged within 24 hours, as designed.
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From: Phoenix AZ & Cayucos CA
’27 AMG SL55(ordered), ‘23 EQS 580 SUV, ‘19 AMG E53 Cpe, ‘48 Willys Jeepster
Our EQS SUV sat in the garage for four months and never got a low 12v battery alert. Unlike the E coupe that alerted three times in the eleven weeks that it was in the dealer waiting for them to throw parts at it.
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From: New England/Florida
2005 SL 500. 2015 S550. 2016 GLE400 2018 S560
I have not technically received a 12 v alert since they changed out my battery. Occasionally I have looked at the service function on the app which has shown the battery at partially charged state. It goes to fully charged within 24 hours 90% of the time.
