SL/R232: Starter Battery Critical Messages
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Joined: Nov 2024
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From: Kent UK
SL55 r232
Starter Battery Critical Messages
I’ve had my 2023 SL55 for a week and get constant warning messages from my Mercedes Me app saying that the starter battery is low.
I have a CTek 5.0 hardwired to the battery which is telling me the battery is in good health. Yet I still get these annoying messages and even got one on the dash today when I went to use the car. The car runs and drives fine. Is there a software update to fix this yet?
I’ve read the thread relating to 2022 models and now “double Lock” the car and keep the key in a faraday box. Before I book it into the dealer is there anything else’s I can do? I’m in the UK.
I have a CTek 5.0 hardwired to the battery which is telling me the battery is in good health. Yet I still get these annoying messages and even got one on the dash today when I went to use the car. The car runs and drives fine. Is there a software update to fix this yet?
I’ve read the thread relating to 2022 models and now “double Lock” the car and keep the key in a faraday box. Before I book it into the dealer is there anything else’s I can do? I’m in the UK.
Last edited by Graeme369; Nov 9, 2024 at 10:17 AM.
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From: GA
‘24 Maserati GranTurismo Trofeo;'22 AMG SL55;'23 Porsche Cayenne S Coupe;'13 Porsche Boxster S
It took MB many attempts and software updates to fix the critical battery problem. If you are getting the message I suspect your car is not up to date with the latest update. FYI, I stopped using the trickle charger (it is also the worst trickle charger I have used - super slow, gets very hot). Currently, I don’t lock the car in my garage. On occasion I have accidentally left the keys in the car overnight. Despite all of this, no more issues with the battery or the messages in the car or on the app.
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Joined: Nov 2024
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From: Kent UK
SL55 r232
Will OTA updates just happen or is this a dealer fix? My car downloaded Mbux 2.4 this morning? But still getting on dash and app messages.
Last edited by Graeme369; Nov 11, 2024 at 06:34 AM.
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From: Marietta, Georgia
2023 AMG sl43
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2023 SL63 + 2021 Cayenne e-hybrid
It took MB many attempts and software updates to fix the critical battery problem. If you are getting the message I suspect your car is not up to date with the latest update. FYI, I stopped using the trickle charger (it is also the worst trickle charger I have used - super slow, gets very hot). Currently, I don’t lock the car in my garage. On occasion I have accidentally left the keys in the car overnight. Despite all of this, no more issues with the battery or the messages in the car or on the app.
Agree x2, you probably have a recall that needs to be done, even if it doesn't show upon a VIN search, go to your dealer and they will tune you up
An actual add to the thread
. . . I have moved to this charger, nice cycling feature, AGM setting and doesn't get as hot as the CTEKHope you are well-- KH
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Agree, I have stopped using the xxx branded CTEK charger (everyone uses them)
Agree x2, you probably have a recall that needs to be done, even if it doesn't show upon a VIN search, go to your dealer and they will tune you up
An actual add to the thread . . . I have moved to this charger, nice cycling feature, AGM setting and doesn't get as hot as the CTEK
Hope you are well-- KH
Agree x2, you probably have a recall that needs to be done, even if it doesn't show upon a VIN search, go to your dealer and they will tune you up
An actual add to the thread
. . . I have moved to this charger, nice cycling feature, AGM setting and doesn't get as hot as the CTEKHope you are well-- KH
Speaking of which, standby mode still a thing?
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2023 SL63 + 2021 Cayenne e-hybrid
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Forgot to add the link, went to Amazon and then started shopping . . . ADD
No affiliation, just a happy customer-- KH
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From: DFW
SL63
Not for nothing, but those AGM(absorbent glass matting) batteries do not like to be overcharged. If you get a charger, make sure it has a full charge cutoff feature, or goes into a very low trickle mode.
I am sure khiroshima recommended a good one at Amazon.
I am sure khiroshima recommended a good one at Amazon.
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OOOOPPPS
Forgot to add the link, went to Amazon and then started shopping . . . ADD
https://www.amazon.com/Battery-Charg...33&sr=8-2&th=1
No affiliation, just a happy customer-- KH
Forgot to add the link, went to Amazon and then started shopping . . . ADD
https://www.amazon.com/Battery-Charg...33&sr=8-2&th=1
No affiliation, just a happy customer-- KH
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2023 SL63 + 2021 Cayenne e-hybrid
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From: Kent UK
SL55 r232
New battery under warranty fixed the issue!
Thanks all for the replies. Dealer fitted new battery under warranty which has fixed the issue. Odd that so many batteries are faulty?!
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Junior Member
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E550 coupe
Battery replacement every 6 months
It seems pretty consistent to me, a couple times a year I’ll need to have the battery replaced under warranty at the dealership….until it’s no longer under warranty, then I’ll pay out of pocket for it.
In 18 months I’ve had 2 batteries replaced and now a couple months into my most recent replacement I am getting sporadic messages about battery low or battery critical. I have had all the service bulletins done and software updates, it still happens. But I’m in the early stages of a new battery so we’ll see if this continues. It usually comes more apparent after a few mobile car washes with the doors open for 30 mins.
I’m in the US so I don’t know if everyone got the vouchers or it’s just us, but my dealership has been unable to figure out how to process the voucher after several calls and a couple weeks now. I’ve seen posts where people just get a check cut to them, that would be nice.
In 18 months I’ve had 2 batteries replaced and now a couple months into my most recent replacement I am getting sporadic messages about battery low or battery critical. I have had all the service bulletins done and software updates, it still happens. But I’m in the early stages of a new battery so we’ll see if this continues. It usually comes more apparent after a few mobile car washes with the doors open for 30 mins.
I’m in the US so I don’t know if everyone got the vouchers or it’s just us, but my dealership has been unable to figure out how to process the voucher after several calls and a couple weeks now. I’ve seen posts where people just get a check cut to them, that would be nice.
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Battery critical warning S350 AMG premium 2022
I keep getting battery critical warnings on my 2 year old S class.
Two battery replacements in this time, the last one just a few weeks ago. Already had battery critical warning on the app and on dashboard.
My tracker app however shows a fully charged battery.
Really getting fed up of these warnings and difficult to know if there is a real problem or not.
My job involves being called at night and this is worrying.
Looking at some of the threads, this does not seem to be a new problem and I cannot understand why Mercedes have not addressed this. I think this is unacceptable for any car, let alone one that costs £95000!
Any suggestions as to things to try would be appreciated; the standby mode would not work for me as apparently disables the alarm.
The car is currently under warranty but my worry is what happens when this end???
Two battery replacements in this time, the last one just a few weeks ago. Already had battery critical warning on the app and on dashboard.
My tracker app however shows a fully charged battery.
Really getting fed up of these warnings and difficult to know if there is a real problem or not.
My job involves being called at night and this is worrying.
Looking at some of the threads, this does not seem to be a new problem and I cannot understand why Mercedes have not addressed this. I think this is unacceptable for any car, let alone one that costs £95000!
Any suggestions as to things to try would be appreciated; the standby mode would not work for me as apparently disables the alarm.
The car is currently under warranty but my worry is what happens when this end???
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SL63AMG
I never get an error message, nothing about the battery. The car is in the winter garage and not connected to anything. I made sure to fully charge the battery once with the charger provided. Then I disconnected it …
The only message that I get is that the car is unlocked.
The only message that I get is that the car is unlocked.
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Posts: 2
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BMW X5
R232 Proper charging endpoints are under the hood
According to the R232 user manual, the charging terminals are directly under the hood usually used if you need to jump the car. I tried connecting the trickle charger directly to the battery terminals in the back of the trunk but still had battery issues. Once I started charging to the charge terminals under the front hood, all battery issues disappeared. This car has two batteries (one small one inside the cabin and one large one in the trunk) so the proper charging terminal under the hood charges both batteries. Problem solved.
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From: Houston, Texas
2022 SL63, 2008 CL63
The boot socket is installed by you or the dealer in the trunk. It connects to the rear battery there. My car has supposedly had all the software updates. I also installed the boot socket and as mentioned before when I use the rear charging method I do get the error on the app and in the car even though the battery is charged. When I connect the charger under the hood no errors. Do you all think I am missing an update?
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SL63AMG
The boot socket is installed by you or the dealer in the trunk. It connects to the rear battery there. My car has supposedly had all the software updates. I also installed the boot socket and as mentioned before when I use the rear charging method I do get the error on the app and in the car even though the battery is charged. When I connect the charger under the hood no errors. Do you all think I am missing an update?
My SL is in the garage for 2-3 months already. No charger connected (I did once charge the battery using the front/hood connections). No issues, no error messages whatsoever.
I only took it out for short runs twice. Starts/runs perfectly.
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Okay I must be missing something.
In my new to me 2023 SL55, there is a 12v battery in the trunk that the Dealer Service Writer told me to hook up the maintainer to. This battery powers all the electronics in the cabin area.
Theres also a battery under the hood that’s 48v. Per the Dealer, no tender for that battery. This makes sense to me because there isn’t any 48v maintainers as far as I know.
Someone correct me if I’m screwed up please.
In my new to me 2023 SL55, there is a 12v battery in the trunk that the Dealer Service Writer told me to hook up the maintainer to. This battery powers all the electronics in the cabin area.
Theres also a battery under the hood that’s 48v. Per the Dealer, no tender for that battery. This makes sense to me because there isn’t any 48v maintainers as far as I know.
Someone correct me if I’m screwed up please.
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From: DFW
SL63
Okay I must be missing something.
In my new to me 2023 SL55, there is a 12v battery in the trunk that the Dealer Service Writer told me to hook up the maintainer to. This battery powers all the electronics in the cabin area.
Theres also a battery under the hood that’s 48v. Per the Dealer, no tender for that battery. This makes sense to me because there isn’t any 48v maintainers as far as I know.
Someone correct me if I’m screwed up please.
In my new to me 2023 SL55, there is a 12v battery in the trunk that the Dealer Service Writer told me to hook up the maintainer to. This battery powers all the electronics in the cabin area.
Theres also a battery under the hood that’s 48v. Per the Dealer, no tender for that battery. This makes sense to me because there isn’t any 48v maintainers as far as I know.
Someone correct me if I’m screwed up please.
I Have been charging my main battery this whole time(1year) and have avoided all the problems that were associated with low battery codes etc.
I have seen special connecters for the trunk accessory battery, but mine is not set up for that.
