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I just received the following message in the Mercedes Me Connect App:
Is this some critical system failure? The car is brand new lol. How to resolve? It’s plugged into standard wall outlet while we wait for L2 charger to get installed next week…
I just received the following message in the Mercedes Me Connect App:
Is this some critical system failure? The car is brand new lol. How to resolve? It’s plugged into standard wall outlet while we wait for L2 charger to get installed next week…
Unlikely.
Like someone else said if it was in for tinting then it is very common. Even if it is wasn't tinting it is still common, if the vehicle was on the dealership's lot for a while the battery didn't get a chance to charge up. Despite being an EQS, the 12V battery still powers Mercedes me connect services (if I remember correctly) and therefore it is constantly pinging MB's servers to help enable functions like remote start, remote un/lock, pre-entry climate control, tracking vehicle location etc. So even if you turn off the vehicle and lock it, the vehicle isn't really completely off. Driving it more allows time for the 12V battery to recharge.
That being said, the 12V battery warning does come pretty early so you don't risk not being able to start the vehicle then allow the EQS high voltage battery to take over afterwards.
After reading these posts about draining the 12v battery while tinting and while sitting idle for a while, what is Mercedes recommending if you plan to store the car for a couple of months. I’ve read where they don’t want you to open the front hood, so how are you supposed to keep the 12v battery charged? I was planning on keeping my 580 stored in my Florida garage for the summer while up north, like I currently do for my S560. I keep a ctek maintenance charger on my S class and haven’t run into any problems when I return to Florida in the winter. I leave my lithium ion golf cart with a full charge before I head north and leave the charger off. I just charge it when I get back in the fall and away we go.
After reading these posts about draining the 12v battery while tinting and while sitting idle for a while, what is Mercedes recommending if you plan to store the car for a couple of months. I’ve read where they don’t want you to open the front hood, so how are you supposed to keep the 12v battery charged? I was planning on keeping my 580 stored in my Florida garage for the summer while up north, like I currently do for my S560. I keep a ctek maintenance charger on my S class and haven’t run into any problems when I return to Florida in the winter. I leave my lithium ion golf cart with a full charge before I head north and leave the charger off. I just charge it when I get back in the fall and away we go.
I think a maintenance charger would be a good idea for a long layover. Just to let you know. I bought my car on Jan 3rd. The next day, with the HV battery at 78%, I left for an 11 day trip. I monitored tha car while I was gone, and nothing changed. Ambient temps in my garage were in the 40's during this time. I returned, and the HV battery was still at 78%. Have not gotten a 12 V battery warning. I drive it daily. Also, I have turned off the interior lights so that, when tinting (my car is tinted) or otherwise when I am experimenting in the garage, the draw on the 12V battery is less. Just my $.02.
After reading these posts about draining the 12v battery while tinting and while sitting idle for a while, what is Mercedes recommending if you plan to store the car for a couple of months. I’ve read where they don’t want you to open the front hood, so how are you supposed to keep the 12v battery charged? I was planning on keeping my 580 stored in my Florida garage for the summer while up north, like I currently do for my S560. I keep a ctek maintenance charger on my S class and haven’t run into any problems when I return to Florida in the winter. I leave my lithium ion golf cart with a full charge before I head north and leave the charger off. I just charge it when I get back in the fall and away we go.
On ICE vehicles there is a standby mode, not sure about the EQS however.
After reading these posts about draining the 12v battery while tinting and while sitting idle for a while, what is Mercedes recommending if you plan to store the car for a couple of months. I’ve read where they don’t want you to open the front hood, so how are you supposed to keep the 12v battery charged? I was planning on keeping my 580 stored in my Florida garage for the summer while up north, like I currently do for my S560. I keep a ctek maintenance charger on my S class and haven’t run into any problems when I return to Florida in the winter. I leave my lithium ion golf cart with a full charge before I head north and leave the charger off. I just charge it when I get back in the fall and away we go.
Just leave the car plugged in and keep it at 50% charge. That will maintain the 12v just fine. Its an EV version of a trickle charger.
Unlikely. Like someone else said if it was in for tinting then it is very common. Even if it is wasn't tinting it is still common, if the vehicle was on the dealership's lot for a while the battery didn't get a chance to charge up. Despite being an EQS, the 12V battery still powers Mercedes me connect services (if I remember correctly) and therefore it is constantly pinging MB's servers to help enable functions like remote start, remote un/lock, pre-entry climate control, tracking vehicle location etc. So even if you turn off the vehicle and lock it, the vehicle isn't really completely off. Driving it more allows time for the 12V battery to recharge.That being said, the 12V battery warning does come pretty early so you don't risk not being able to start the vehicle then allow the EQS high voltage battery to take over afterwards.
BTW, everything in the car runs 12v except the drivetrain. That's why people run into problems after a few hours; computers, screens, audio and millions of indoor lamps draw a lot of power.
Just leave the car plugged in and keep it at 50% charge. That will maintain the 12v just fine. Its an EV version of a trickle charger.
Is this true? It was my understanding that the 12V battery only received charge from the HV battery when the car is switched on. So it is possible to have an adequately charged HV battery and have the 12V battery still drained by interior lights, computers, accessories, etc. For instance, sitting in your garage with the interior lights on and learning MBUX for hours, or leaving the doors open while tinting might minmally impact the HV battery, but drain the 12V battery. Am I wrong in this perception? Not accusing....just inquiring for a better understanding of the process. My forays onto the Taycan and eTron sites seem to suggest that the 12V battery is not charged by the wall charger, but by the HV battery while you drive the car.
Is this true? It was my understanding that the 12V battery only received charge from the HV battery when the car is switched on. So it is possible to have an adequately charged HV battery and have the 12V battery still drained by interior lights, computers, accessories, etc. For instance, sitting in your garage with the interior lights on and learning MBUX for hours, or leaving the doors open while tinting might minmally impact the HV battery, but drain the 12V battery. Am I wrong in this perception? Not accusing....just inquiring for a better understanding of the process. My forays onto the Taycan and eTron sites seem to suggest that the 12V battery is not charged by the wall charger, but by the HV battery while you drive the car.
Supposedly the HV battery keeps the 12V battery as long its at an adequate state of charge. At least thats my understanding.
Is this true? It was my understanding that the 12V battery only received charge from the HV battery when the car is switched on. So it is possible to have an adequately charged HV battery and have the 12V battery still drained by interior lights, computers, accessories, etc. For instance, sitting in your garage with the interior lights on and learning MBUX for hours, or leaving the doors open while tinting might minmally impact the HV battery, but drain the 12V battery. Am I wrong in this perception? Not accusing....just inquiring for a better understanding of the process. My forays onto the Taycan and eTron sites seem to suggest that the 12V battery is not charged by the wall charger, but by the HV battery while you drive the car.
Supposedly the HV battery keeps the 12V battery as long its at an adequate state of charge. At least thats my understanding.
Quote: "If leaving the vehicle idle for extended periods, park the vehicle with the high-voltage battery condition of charge at between 30% and 50%. Do not keep the high-voltage battery continuously connected to power supply equipment". So no, don't leave it plugged....I guess you should just connect the 12 V to a trickle charger if leaving it off for many mths. Again, stupid "no opening hood"....
Last edited by c4004matic; Mar 21, 2022 at 10:02 PM.
I checked with a contact at MB and the following is the recommendation for long term storage.The high-voltage battery maintains the 12V system. the recommendation for long-term storage is:
Before storage, plug-in the EQS to charge the high-voltage battery up to a max of 50%
Once the vehicle is charged to 50%, unplug the car.
The vehicle can remain stationary without the need for a 12V maintainer.
Check the status of the high-voltage battery every 6 weeks, if the high-voltage battery drops below 30% the vehicle must be plugged in.
I checked with a contact at MB and the following is the recommendation for long term storage.The high-voltage battery maintains the 12V system. the recommendation for long-term storage is:
Before storage, plug-in the EQS to charge the high-voltage battery up to a max of 50%
Once the vehicle is charged to 50%, unplug the car.
The vehicle can remain stationary without the need for a 12V maintainer.
Check the status of the high-voltage battery every 6 weeks, if the high-voltage battery drops below 30% the vehicle must be plugged in.
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.
BTW, everything in the car runs 12v except the drivetrain. That's why people run into problems after a few hours; computers, screens, audio and millions of indoor lamps draw a lot of power.
My EQS was brand new when I took it into get PPF installed straight from the dealership lot. During the installation process the 12v died and the vehicle would not start up. It was completely dead. The PPF installers likely did not realize they were slowly draining the battery during the 4 day installation process. Had to tow the vehicle back to the Mercedes dealership. The service tech at the dealership explained that when the 12v battery dies, Mercedes has to use a special device to charge it up. In my case this is device had to get shipped from Germany (as my Mercedes’ dealer did not have it in their shop, and I’m guessing that many other do not have this device either).
My car has been at the dealership for a few days now and am waiting to for that device to get in. Hoping it’ll recharge the 12v battery. I will keep others posted as the 12v draining quickly (especially on a new car that has barely been driven) seems to be an issue that Mercedes and it’s dealers are not well versed in.
My EQS was brand new when I took it into get PPF installed straight from the dealership lot. During the installation process the 12v died and the vehicle would not start up. It was completely dead. The PPF installers likely did not realize they were slowly draining the battery during the 4 day installation process. Had to tow the vehicle back to the Mercedes dealership. The service tech at the dealership explained that when the 12v battery dies, Mercedes has to use a special device to charge it up. In my case this is device had to get shipped from Germany (as my Mercedes’ dealer did not have it in their shop, and I’m guessing that many other do not have this device either).
My car has been at the dealership for a few days now and am waiting to for that device to get in. Hoping it’ll recharge the 12v battery. I will keep others posted as the 12v draining quickly (especially on a new car that has barely been driven) seems to be an issue that Mercedes and it’s dealers are not well versed in.
This isn’t quite accurate (technically at least). My car’s 12V battery was completely drained as part of tinting and PPF as well and the Mercedes dispatched road assistance guy hooked it up to a portable 12V battery and it started right up. After a 20-30 minute drive it was as good as new.
This isn’t quite accurate (technically at least). My car’s 12V battery was completely drained as part of tinting and PPF as well and the Mercedes dispatched road assistance guy hooked it up to a portable 12V battery and it started right up. After a 20-30 minute drive it was as good as new.
I’m only relaying what my Mercedes’ dealership explained to me.
It’s my understanding that there are two 12v batteries, one in the front of the vehicle and one in the rear. Perhaps one can be charged in the traditional way, but the other requires something more detailed. Who knows it’s a bit of conjecture until I get the car back and they can explain in greater detail what they did.
I agree, it makes no sense. If they are concerned about charging the 12v in place why not just take it out and hook it up to a charger or just replace it with a new battery. That's going to happen eventually anyway.
I’m only relaying what my Mercedes’ dealership explained to me.
It’s my understanding that there are two 12v batteries, one in the front of the vehicle and one in the rear. Perhaps one can be charged in the traditional way, but the other requires something more detailed. Who knows it’s a bit of conjecture until I get the car back and they can explain in greater detail what they did.
Perhaps. In my case the car was completely dead, nothing was on. The charger was hooked up to the 12V battery under the front hood and it started right up.
My EQS was brand new when I took it into get PPF installed straight from the dealership lot. During the installation process the 12v died and the vehicle would not start up. It was completely dead. The PPF installers likely did not realize they were slowly draining the battery during the 4 day installation process. Had to tow the vehicle back to the Mercedes dealership. The service tech at the dealership explained that when the 12v battery dies, Mercedes has to use a special device to charge it up. In my case this is device had to get shipped from Germany (as my Mercedes’ dealer did not have it in their shop, and I’m guessing that many other do not have this device either).
My car has been at the dealership for a few days now and am waiting to for that device to get in. Hoping it’ll recharge the 12v battery. I will keep others posted as the 12v draining quickly (especially on a new car that has barely been driven) seems to be an issue that Mercedes and it’s dealers are not well versed in.
I'm not an expert or electrical engineer, but my understanding of batteries is that traditional 12V Lead Acid batteries (as used in ICE cars) can be charged with traditional battery charger even when totally dead. Lion on the other hand, have to be charged according to a specific power algorithm when they are completely dead as there is a risk of fire or explosion if too much current is applied when Lion are completely dead. I'm assuming the 12V battery in the EQS is a traditional Lead Acid battery which is why others have posted that they just charged it via traditional means and the car started right up. Maybe your dealer thinks the 12V battery is Lion and hence needs special equipment to recharge it? Just a thought....
Hi all - thanks for the great info on the battery issue - I have a Jan 2022 EQS450. I have not experienced the 12v battery issue yet but just wondering if it has anything to do with the max charge level of the HV battery. Mercedes recommends not charging to 100% all the time but I wonder if it is required in order to fully charge the 12v battery?? Just a thought. When you experienced the 12v failure, had you been charging the HV battery to the recommended 80% max or 100% max?
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.
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