12 volt battery low critical
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Joined: Feb 2025
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12 volt battery low critical
I've had my 2022 CPO EQS 450+ for about a month. Since a couple days after taking it home, I've been getting the message '12V Battery Low' on the phone app, not on the car itself. The phone app advises me to drive the car for a while. I did that, problem did not go away, so I took it to the dealer, where they replaced the 12V battery. The warning on the phone has not gone away 2 weeks later. Dealer says to bring it back. Anyone else who has dealt with this problem? The car runs fine. There are no lights on or other obvious parasitic loads, and the battery critical message comes on even after I've just driven for an hour, never goes away.
Member
Joined: Jul 2007
Posts: 145
Likes: 30
From: Memphis, TN
Battery
I've had my 2022 CPO EQS 450+ for about a month. Since a couple days after taking it home, I've been getting the message '12V Battery Low' on the phone app, not on the car itself. The phone app advises me to drive the car for a while. I did that, problem did not go away, so I took it to the dealer, where they replaced the 12V battery. The warning on the phone has not gone away 2 weeks later. Dealer says to bring it back. Anyone else who has dealt with this problem? The car runs fine. There are no lights on or other obvious parasitic loads, and the battery critical message comes on even after I've just driven for an hour, never goes away.
Super Member
Joined: Dec 2022
Posts: 750
Likes: 225
From: Sweden
2023 EQE SUV 500 4Matic
If you haven't already, do some searching on "12v battery" in this forum and https://www.mbeqclub.com
You will see that "12 volt battery low" issues are a fairly common complaint for EQ* vehicles, as well as for other EV brands.
Running the HV battery down to 20% is not the root cause, though it may appear to be as, I believe charging the HV battery also charges the 12v battery at the same time (not 100% sure on this). Anyway, you should not fear running your HV battery down to 20% -- or even 10% for that matter.
In most cases, it seems that EQ people with this problem had early-production vehicles (2021-2022) and that their issues were caused by the HV battery not automatically recharging the 12v battery when parked.
This was frequently resolved by the dealer with a software update.
So, my recommendation is for you to check with your dealer and urge them to consider relevant software updates.
You will see that "12 volt battery low" issues are a fairly common complaint for EQ* vehicles, as well as for other EV brands.
Running the HV battery down to 20% is not the root cause, though it may appear to be as, I believe charging the HV battery also charges the 12v battery at the same time (not 100% sure on this). Anyway, you should not fear running your HV battery down to 20% -- or even 10% for that matter.
In most cases, it seems that EQ people with this problem had early-production vehicles (2021-2022) and that their issues were caused by the HV battery not automatically recharging the 12v battery when parked.
This was frequently resolved by the dealer with a software update.
So, my recommendation is for you to check with your dealer and urge them to consider relevant software updates.
MBWorld God!
Joined: Dec 2019
Posts: 32,217
Likes: 6,275
If you haven't already, do some searching on "12v battery" in this forum and https://www.mbeqclub.com
You will see that "12 volt battery low" issues are a fairly common complaint for EQ* vehicles, as well as for other EV brands.
Running the HV battery down to 20% is not the root cause, though it may appear to be as, I believe charging the HV battery also charges the 12v battery at the same time (not 100% sure on this). Anyway, you should not fear running your HV battery down to 20% -- or even 10% for that matter.
In most cases, it seems that EQ people with this problem had early-production vehicles (2021-2022) and that their issues were caused by the HV battery not automatically recharging the 12v battery when parked.
This was frequently resolved by the dealer with a software update.
So, my recommendation is for you to check with your dealer and urge them to consider relevant software updates.
You will see that "12 volt battery low" issues are a fairly common complaint for EQ* vehicles, as well as for other EV brands.
Running the HV battery down to 20% is not the root cause, though it may appear to be as, I believe charging the HV battery also charges the 12v battery at the same time (not 100% sure on this). Anyway, you should not fear running your HV battery down to 20% -- or even 10% for that matter.
In most cases, it seems that EQ people with this problem had early-production vehicles (2021-2022) and that their issues were caused by the HV battery not automatically recharging the 12v battery when parked.
This was frequently resolved by the dealer with a software update.
So, my recommendation is for you to check with your dealer and urge them to consider relevant software updates.
MBWorld Fanatic!
Joined: Apr 2023
Posts: 1,568
Likes: 590
From: Occupied Palestine
2025 Maserati Grecale Folgore and 2024 Jaguar F-PACE SVR
Only requirement is contactors have to be closed to charge the 12V. That Mercedes Me error message that says to drive around is for ICE vehicles with alternators.
