In the middle of snow storm currently, and I checked my mercedes app and it says "very low battery". FWIW the car has like 300 miles did like maybe 250 miles in the past 2 weeks I've had it. Is this normal? I left my 2019 M850i coupe for a month in cold temperatures and didn't get that warning ever. I just drove circles in my condo garage to charge it up a bit and the warning on the app is gone.

 

Yep I have/had the same issue- when I dont drive it for more than a few days I have it hooked up to the provided tender.

 

Did you ever go to the dealership about this? Or is this the only solution to leave it charging every few days?

My condo doesn’t really have outlets in the garage at least in my spot

 

This is a known problem with our cars as well as the R192 SLs. As Vic55 said, hooking up to the trickle charger in cold weather is the best solution. It also helps to turn off the smart key if it is in close proximity to the car, as the car will continuously search for it, burning battery along the way. There are several other threads on this forum about this problem, so try the search function for "battery" to get some further feedback/suggestions.

 

just a bit tougher for me given I live in a condo.

it seems like some have had software updates? Did you notice any changes in your GT

 

I daily drive mine and still frequently get those battery messages. It has to be because of all the digital extras constantly using it in the background. I get the rain monitoring messages almost daily. Has anyone tried swapping in an aftermarket battery? Wondering if that would make any difference.

 

I could have gone to the dealer as they offered a new battery but I just am too lazy to go there and instead charge. Its just a 110 so if you have a plug close or even far you can use an extension cord??

I havent driven the car in a week exactly and I just got the stupid app warning (low 12v battery blah blah) so I plugged it in earlier today and its all good now. But it will come back no matter what.

 

Out of curiosity, should the C192 platform be fitted with an AGM battery rather than a lithium battery like the previous C190, or am I mistaken?

 

Not sure if this will last long enough to fully charge your battery.. Plug your charger in when you don't have an outlet.. Better than nothing. Isn't that the Mercedes motto?

https://www.walmart.com/ip/OUPES-Exo...me/15466552099

 

Yes, I get this error all the time. Very annoying!

I am going to take it in for its first service soon (I had had the car for one year now), and I will ask them about it.

 

FWIW, I did order a jumpstarter to keep in the car

 

Let us know how it goes! My car is getting some color PPF done, so will probably visit the dealership in 1.5 weeks or so

 

When I took mine in for it's first service a month ago they replaced my battery under warranty. They said it wasn't holding a charge. I too often received low battery warnings.

I advise you to tell your ppf installers to hook up the battery tender when you are getting your work done. My battery died during my installation and I had to manually unlock and pry the handle open for the door.

 

?

 

I think mine is an agm.

 

yep, already told the guy to use the battery tender in the white box.

did the new battery end up fixing things for you?

I also drove like 2-3 hours before drop off haha

 

Have had any issues as of yet. Fingers crossed...

 

The 2024/ 2025/ 2026 Mercedes-AMG GT 55 and 63 utilize a dual-battery system to manage its high electrical demands.

The system consists of two distinct units:

• Main Starter Battery: This is the primary battery (often a heavy-duty AGM unit) responsible for providing the high cold-cranking amps needed to start the handcrafted 4.0L V8 Biturbo engine.
• Auxiliary/Accessory Battery: A smaller secondary battery that powers the vehicle's complex electronics, such as the MBUX infotainment system, ambient lighting, and active safety sensors, while the engine is off or under heavy load. This setup prevents these "gizmos" from draining the starter battery, ensuring the car can always turn over.

A low battery warning on your Mercedes-AMG GT 55/63 could refer to either the main starter battery or the auxiliary (backup) battery, and the car usually gives you a specific message to tell them apart.

The car's onboard computer (MBUX) typically uses distinct messages for each battery:

• Main Starter Battery (12V/48V):
  • The Warning: Usually says "12V Battery: See Owner's Manual" or "Stop Vehicle: Charge Battery".
  • What it means: The primary battery that starts your engine and powers most high-load systems is low. This is often caused by leaving lights on, short trips where the alternator can't recharge it, or simple old age.
  • The Risk: If you ignore this, the car might not start the next time you turn it off.
• Auxiliary Battery / Voltage Converter:
  • The Warning: Typically displays as "Auxiliary Battery Malfunction".
  • What it means: This smaller backup unit (often a capacitor or small battery) is failing. It supports sensitive electronics like the gear selector, start-stop system, and safety sensors.
  • The Risk: The car will usually still drive and start fine, but your Eco Start-Stop might stop working, and certain electronic "comfort" features might behave strangely.

• The "Secret" Menu: You can often view the exact real-time voltage of your batteries through the "Workshop" menu on your digital instrument cluster. A healthy battery should sit around 12.6V with the engine off and jump to 14V+ once the engine is running and the alternator kicks in.
• Battery Tenders: If you don't drive your AMG GT 55/63 daily, it is highly recommended to use a Mercedes-Benz Battery Trickle Charger to keep both systems topped off and avoid these warnings.

The main 12V battery is located in the trunk (rear luggage compartment).

• Access: To reach it, you usually need to lift the trunk floor panel (the luggage area floor). It is often housed in a dedicated compartment toward the center or right side to help balance the weight of the front-mounted V8 engine.
• Jump-Starting: Even though the battery is in the back, you do not have to access it to jump-start or charge the car. There are dedicated remote jump-start terminals under the hood:
  • Positive (+): Look for a red sliding plastic cover near the firewall or passenger-side strut tower.
  • Negative (-): A dedicated brass or silver grounding pin/nut is located nearby on the vehicle frame.

Auxiliary Battery (Voltage Converter) Location
In most modern Mercedes-AMG models of this generation, the "auxiliary battery" is actually a solid-state voltage converter (capacitor) rather than a traditional lead-acid battery.

• Access: It is typically located in the passenger-side footwell.
• How to reach it: You would need to pull back the floor mat and the carpet panel under the dashboard/glovebox area to find the unit tucked behind a plastic cover or bracket.

 

If it got a software update, it only marginally helped with the problem. Extreme cold temperatures still result in the "12v battery extremely low" error message in the app if i don't keep it on the charger.

 

just came back from the dealership after my color ppf. They are saying there’s no issues with it and no available updates. But I feel like this can’t be. I’m going to Japan for 10 days this weekend so will see if the car starts up. I have a jumpstarter so will see.

Will record how many days it lasts after a long drive the day before I arrive

 

actually just found out this car has a battery saving mode called “Stand By Mode”. Activated that and it said I had 7 weeks or so it could last.

 

Where do you activate this??

Edit--- found this on Ai

To activate battery-saving "Standby Mode" in a Mercedes-Benz (often for long-term parking), turn the ignition to accessory mode (press start twice without touching the brake). Navigate to Settings > Vehicle > Other Functions and select Activate Standby Mode.
Mercedes-Benz USA +3

 

My experience with that function is that activating it and the subsequent deactivation will reset some of your preferences like welcome light preferences and some other customizations.

Once activated you will need to hit unlock on the key fob to wake up the car. Door handles will not open otherwise

 

I had a similar experience - was a bit of a PITA, which is why i didn't mention it earlier. It did extend battery life when it was really cold, but it did not eliminate the problem. I thought it was more trouble than it was worth, especially since using a charger isn't a problem for me. Understand that the OP is in a different parking situation, so hope this helps!