View Battery Voltage ?
Thread Starter
Member
Joined: Sep 2022
Posts: 156
Likes: 26
From: Texas
C300 W206 2022
What doesn't help is that the Mercedes Benz App is woefully inadequate. It still has the message "Batt. Health Very Low" and "Partially charged" from weeks ago with no Date / Time Stamp so you can't tell when the readings were taken. It is permanently there now with no dismiss option, just "Book an Appointment". That is why I decided not to renew the Connect Subscription for a very buggy app with limited functionality. When I got the car, the app wouldn't update vehicle status for the first year on my Pixel phone with the latest Android. They eventually told me it is a known issue and they were working on it. When it came time for renewal for the non-working service, they refused a complementary renewal!
I have read elsewhere that MB is very picky about replacing battery under warranty and their tests always show them to be functional. My question is, if I take it to the Dealer because I cannot put the car in Standby mode and they do not find a problem , just that the battery is not charged or for any other no problem found issue, is there a diagnostic fee?
I have read elsewhere that MB is very picky about replacing battery under warranty and their tests always show them to be functional. My question is, if I take it to the Dealer because I cannot put the car in Standby mode and they do not find a problem , just that the battery is not charged or for any other no problem found issue, is there a diagnostic fee?
MBWorld God!
Joined: Dec 2019
Posts: 32,217
Likes: 6,275
What doesn't help is that the Mercedes Benz App is woefully inadequate. It still has the message "Batt. Health Very Low" and "Partially charged" from weeks ago with no Date / Time Stamp so you can't tell when the readings were taken. It is permanently there now with no dismiss option, just "Book an Appointment". That is why I decided not to renew the Connect Subscription for a very buggy app with limited functionality. When I got the car, the app wouldn't update vehicle status for the first year on my Pixel phone with the latest Android. They eventually told me it is a known issue and they were working on it. When it came time for renewal for the non-working service, they refused a complementary renewal!
I have read elsewhere that MB is very picky about replacing battery under warranty and their tests always show them to be functional. My question is, if I take it to the Dealer because I cannot put the car in Standby mode and they do not find a problem , just that the battery is not charged or for any other no problem found issue, is there a diagnostic fee?
I have read elsewhere that MB is very picky about replacing battery under warranty and their tests always show them to be functional. My question is, if I take it to the Dealer because I cannot put the car in Standby mode and they do not find a problem , just that the battery is not charged or for any other no problem found issue, is there a diagnostic fee?
MBWorld God!
Joined: Dec 2019
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This forum member (that previously chimed in a few post ago) had this same issue, bad battery but fully charged: https://mbworld.org/forums/c-class-w...ml#post9169427
MBWorld Fanatic!
Joined: Oct 2019
Posts: 5,151
Likes: 1,765
From: Colorado
G550
Take your vehicle to any auto store -- they can put a load tester on your battery and determine its health. I replaced my OE battery at about 42 months with a $240 Autozone Duralast Platinum -- 36 month free replacement warranty. It's now 27 months in and no problems. Even if it dies in month 37, that's still only $6.67/month knowing I have a good battery and warranty. Most auto stores have comparable batteries and warranties. Not worth my time to argue with a MB dealer.
Thread Starter
Member
Joined: Sep 2022
Posts: 156
Likes: 26
From: Texas
C300 W206 2022
Took it to the dealership this morning, they just called and said that the battery was testing low and their test called for a replacement. Thank you all for your help in diagnosing this issue.
MBWorld God!
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Good they are replacing it, explains why the standby mode is refusing to activate.
MBWorld Fanatic!
Joined: Jun 2012
Posts: 1,229
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From: Toronto
2022 E53 AMG
In the MB App you can see the battery information under the "Service option". Mercedes also state that if you are going away for some time, you should put the car into sleep mode where all features are turned off except the security but you will also loose connection to the app.
Second to that, in your Mercedes owner manual is warns that the 12v can fail / discharge and or be damage for not driving the car often or driving the car on short trips often which does not give the charging system enough time to charge the battery.
Second to that, in your Mercedes owner manual is warns that the 12v can fail / discharge and or be damage for not driving the car often or driving the car on short trips often which does not give the charging system enough time to charge the battery.
MBWorld God!
Joined: Dec 2019
Posts: 32,217
Likes: 6,275
In the MB App you can see the battery information under the "Service option". Mercedes also state that if you are going away for some time, you should put the car into sleep mode where all features are turned off except the security but you will also loose connection to the app.
Second to that, in your Mercedes owner manual is warns that the 12v can fail / discharge and or be damage for not driving the car often or driving the car on short trips often which does not give the charging system enough time to charge the battery.
Second to that, in your Mercedes owner manual is warns that the 12v can fail / discharge and or be damage for not driving the car often or driving the car on short trips often which does not give the charging system enough time to charge the battery.
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MBWorld God!
Joined: Dec 2019
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Tried Standby mode again after driving with the battery amps at 3.5v, still wouldn't activate "Charge Insufficient to Activate Standby Mode". So at least in my case, this option is unusable unless I were to drive to the airport, where it could possibly work but unreliably.
Member
Joined: Jun 2025
Posts: 86
Likes: 20
From: SoCal, USA
C300
MB Service told me that my C300 needs to be driven about 15 miles X 2 daily to keep the battery fully charged. I was getting the Mercedes.me app alert of the battery not being fully charged, since I'm a teacher and am off for the summer. So now I am driving the car around town just to keep the battery up. Never had that issue with my Acura..
I also had the Standby battery alert. That's a false alert as far as I can tell, because I was able to implement Standby by simply pressing the Start button twice with my foot off the brake.
Oh, and Standby, once implemented, goes away as soon as you start your car.
I also had the Standby battery alert. That's a false alert as far as I can tell, because I was able to implement Standby by simply pressing the Start button twice with my foot off the brake.
Oh, and Standby, once implemented, goes away as soon as you start your car.
MBWorld Fanatic!
Joined: Oct 2019
Posts: 5,151
Likes: 1,765
From: Colorado
G550
Buy a 1A maintainer such as Noco's (https://www.autozone.com/test-scan-a.../606157_0_0?se) for $30 and save your fuel.
MBWorld God!
Joined: Dec 2019
Posts: 32,217
Likes: 6,275
MB Service told me that my C300 needs to be driven about 15 miles X 2 daily to keep the battery fully charged. I was getting the Mercedes.me app alert of the battery not being fully charged, since I'm a teacher and am off for the summer. So now I am driving the car around town just to keep the battery up. Never had that issue with my Acura..
I also had the Standby battery alert. That's a false alert as far as I can tell, because I was able to implement Standby by simply pressing the Start button twice with my foot off the brake.
Oh, and Standby, once implemented, goes away as soon as you start your car.
I also had the Standby battery alert. That's a false alert as far as I can tell, because I was able to implement Standby by simply pressing the Start button twice with my foot off the brake.
Oh, and Standby, once implemented, goes away as soon as you start your car.
Member
Joined: Jun 2025
Posts: 86
Likes: 20
From: SoCal, USA
C300
I actually bought a Schumacher charger/maintainer for about 4X that price and it works well. The issue was with the car's computer, which was falsely showing a battery issue. They reset the system and the issue "went away." Second time I had a reset resolve an issue- I was getting a check engine light about once a week and it wasn't the gas cap. These cars have electrical/computer systems than can get a bit corrupted and throw up false alerts.
That's how I know the Standby low battery alert was false. My battery was showing 100% on the charger but the car was reporting low charge.
That's how I know the Standby low battery alert was false. My battery was showing 100% on the charger but the car was reporting low charge.
