This feels like selective memory to me and incorrect. The MB’s of that era had significant mechanical, electric and quality issues.

Today’s cars are nothing like that. We just have very complex cars that are highly dependent on well written software. Also much of it isn’t manufacturer dependent like the 48v issues, much of it are going back to the supplier that makes them for most brands.

To the OP, the old SL’s were stupid simple in terms of tech and but also had their fair share of issues as soon as the options added up.

The R129 600 SL was anything but trouble-free…

 

Ah, for the wonderful, bygone days of “stupid simple” cars that actually WORKED!

 

We can certainly blame the suppliers for the myriad maladies but MB specs and picks the suppliers. I'd go back and look at design and engineering parameters. Complexity that is designed into the cars often creates the problems. An example that comes to mind is the ABC system........compare it to a magnetorheological shock. The biodegradable wiring from 1992-1995, beyond dim witted yet MB NEVER admitted ANY fault.

I'm really debating ordering a SL63eS.............certainly not until/if the beta testing is resolved.

 

Remember those TV ads MB used to run? They would show one of their new cars being driven in frozen, Arctic conditions, then in what looked like the Sahara Desert, then in Monsoon rains, with the narrator going on and on about the incredibly stringent testing that every new Mercedes-Benz model was subjected to. It seems that today, they design the car, build the car, promote the car, sell the car and let the unsuspecting customers “test” them. By the time the beta testing is done, a new model is being introduced. This is not how it’s supposed to be done.

 

I have not had the car on the trickle charger and have not received any battery messages. Last night I decided to put the car on the trickle charger to see what would happen. Sure enough I started to get the low battery messages. This morning the car was fully charged. I got in the car and was warmly greeted with the 12V battery needs to be charged message. I drove around doing errands this afternoon. When I got back home, I put the car back on the trickle charger. I got two more critical battery messages. It seems that the MB trickle charger is tripping something that causes the battery to discharge. I checked the voltage with my Valentine 1 app. It reads 11.9 volts even though the car is on the trickle charger and the 3rd amber light is on (1 stage below full). I have a service appt on Tuesday.

 

I’ve purchased six new 911s over the years, (993, 996, 996 Turbo, 991.2, 991.2 GTS, and 992) and EVERY one of them had more problems than my SL55. And those didn’t have phone apps to report meaningless issues to me.

 

Sorry you had so many problems with your 911’s. Mine were wonderful.

 

I got a call from the dealership. MB wants to install some additional software updates and replace the trickle charger. MBUSA mentioned to the dealer that the logs showed that I don’t lock my car. I told the dealer that I don’t lock it when it is parked in my garage at home. I reminded them that the low battery messages get triggered when I use the trickle charger. I pointed out that if they want to go down the locking the car rabbit hole, it requires a double locking procedure not just simply locking the car. At this point, I am toying with MBUSA since it looks like they are still scratching their heads trying to figure out the solution.I tend to keep my cars for two to three years, so now is about the time for me to start thinking about my next toy. The list so far is: the new Aston Martin Vantage, DB12, Maserati MC20, Gran Turismo Folgore, and the McLaren Artura. In the meantime, I hope to get the SL back next week and enjoy it for the next year or so.

 

Our dealer contacted me last week. He spoke with a veteran engineer at MBUSA who ran our VIN. He said he is ‘confident’ they have a fix for the continuing electrical issues. He asked me to wait until he shop lead was back from vacation (we did). They picked up the car last Tuesday and we told them to keep it until Feb 28th as we will be gone anyway. He informed me on Friday that the ‘fix’ is going well (whatever that means). This morning I thanked him for his support and persistence with MB, and told him to tell MB, we will return the car for a full refund or credit if this situation reoccurs. He said he understood and gave me the contact information for MB TEV (top end vehicles) customer service. Stay Tuned.

 

Hi

is your SL still free of electrical issues?

 

“Top end vehicles?” Most every MB of the 17 new ones I have had has been very close to a top line vehicle and I have never heard of this designation before. Please, if you get any more information on this connection, please share it here.

 

How is your electrical issue?

apparently ‘Top End Vehicle’ designation is something new

 

How is your electrical issue now?

 

How is your electrical issue now

 

TEV? Called my dealership they never heard of such a thing, they said if it's in a lemon law territory then you have to go that route.

 

How is your car now?

 

Good Lord, you’ve managed to pick three brands whose records of reliability make our AMG SLs seem like Lexus. Basing this on prior ownership of three Astons and three Maseratis. Never owned a McLaren.

 

How is your SL now?

 

I too have owned 3 Astons and 3 Maseratis. I had a problem with one (my Quattroporte with 4 dead batteries). For some reason, MBUSA still refuses to let the dealer replace the battery. Let’s see if the latest batch of software updates solves the battery problem. I’m still rooting for my SL.

 

Not negating your comment, but tossing in an opposing view; I moved to the SL from a 2019 Vantage, it had zero issues . . . It was throwing some weird codes about a year ago, I changed the battery (overly complicated DIY) and not a single code since. I'm not going to lie, I saw the new Vantage after taking delivery of the SL and had a bit of buyer's remorse . . . The reality is that, I will enjoy the SL and wait a couple years, depreciation will take a HUGE bite out of the British car, REALLY liking the 0.2 version of the Vantage, KH

 

Khiroshima,

So what is your battery issue? I thought I was in SL/R232 battery related issue & hoping to find solution...

Anyway, I picked up My 2022 SL63 from dealer today after 2 weeks of diagnostic & reprogramming of darn software (see service ticket)
Note that there is 48 Volt battery under the battery post inside engine compartment (they said in previous visit that SL63 only has one 12volt battery in the trunk) and that now has changed

Problem still continues that;
Battery voltage in the trunk is still low even after driven 40 minutes on highway (only 12.3 volt when it should been at least 12.7 or above)
When battery charger is connected to battery directly on battery post, Mercedes App triggers Low Voltage Warning.
When battery charger is connected to battery before BMS sensor on negative post, No warning message

After they updated software, I do not get Low Battery Warning following engine shut off, and this is still to verify clear fix yet or not.

In my premature conclusion of What is clear is that; Direct battery charger connection to battery post will still trigger Low Battery Warning through App even battery is fully charged but if negative terminal is connected before BMS then it'll not.

Time will tell & I'll report back here if this is resolved.

Continue into next morning;
Checked battery voltage on trunk battery terminal & it is 12.46 volt and also checked on engine compartment jump terminal & it is 12.41 volt, that is only 70 to 75% charge state in AGM battery.
Obviously battery is not being fully chrged or there is something draining battery by using trunk battery connection point either directly to battery post or before BMS sensor

I decided to use engine compartment post, now knowing there is additional 48 volt battery under the post and somehow connected. this time, I routed charger clamp & wire in a manner that I can close hood completely while charger is being connected(To make sure car is not being wake up state).

Started charge and charger indicate 50% charged state and went into full charge cycle with 15 amp (I'm using Black & Decker 15 amp smart charger since Mercedes Charger(4.5 amp) takes forever on all this test)

No battery low warning was triggered through App & trunk battery were @ 13.1 volt indicating full charge are being applied

I think This pretty much indicate proper charging connection point is under the hood and driving test still remain to make sure this is fixed.

Continue with Driving Test;
Checked battery voltage from trunk battery before going out for driving test, voltage is 12.55 volt (I think BMS is maintain or limiting this battery charge level to be about 75% charged state, this never goes up above 12.6 volt on my SL63)
Drove about 75 mile on highway with average speed over 70 mph in rain, pulled into garage, turned off engine & checked voltage level off trunk battery, 12.45 volt with fan running in full speed indicating battery charging system is working and best of all, No More Low Battery Warning on dash nor App message.
I believe It is safe to assume items on this service done finally fixed that irritating Low Battery Warning after shutting down engine and random such behavior.

It is difficult to estimate how long my battery will hold charge before it triggers low battery warning without charger being connected but I'll guess it'll be about 10 to 14 days (from my past experience with this car), if I let go without charging it, Critical Battery Warning will kick in and not able to start car

For SL63 owner, I'd recommend do update as it shows on my service ticket, use higher power smart charger than Mercedes 4.5 amp trickle charger, use engine compartment charging point per SL Manual, Plug-in charger if you are not driving 7 day and lock vehicle with hood completely closed while being connected to charger.
For SL55 owner, I don't have suggestion as software are not same with SL63

If my same issue (Battery Low Warning while being charged or after turn off engine) comes back, I'll report back here

I know it just pain on the butt having this issues & connecting to charger so often but they are common thing to maintain battery in good health (I still have original auxillary battery on my 2005 SL55 amg that has 120k mile on it) and also my 2022 Ford F150 Lariat pick up truck that I have to put on a charger when it's sitting more than 10 days in average and my 2015 Maserati about every 10 days when it's sitting on drive way.

So Good Luck to you all & make good habit out of it!

 

FYI: The reported issues on MB are apparently not limited to a few forum posters. Consumer Reports( I'm not convinced of their overall validity) rated BMW #1 and MB #29. Alfa Romeo was #28.
I suspect MB has a problem.......Alfa beating MB!!!

 

That’s truly embarrassing. Fortunately I’ve had no real trouble with mine.

 

I brought my 2022SL63 to my local MB dealership looking at a GT53, when I suggested I might have interest first response was we can't take your SL in on trade, we still have new ones to sell # 2 fuel pump recall prohibits them from selling it until that issues has been resolved. It looks like you can't unload these to a MB dealer. They have three 2023 SL'S but two are 43 one 63. I guess I will have no choice about moving on to some other vehicle. On a positive note my vehicle has been okay, only one issue. Then again I only have 250 miles on it. I just don't want to deal with issues after hearing all the issues on here. I have a 2024 RS6 and it's really a great vehicle.

 

Fastcars1969,

I had my SL63 done 3 repairs for same battery low warning indicator & excessive battery self discharge rate, sitting at dealer over total of a month. I know I could lemon that & unload it if I wanted to but I still love it for that brut sound & unbeatable 4 wheel drive handling with just enough massive power.

I was going to order Porsche 911 4 GTS & I was on top of waiting list before I test drive my 2022 SL63, after that, I changed my mind & never looked back at underpowered, clumsy, rattling Porsche 911 4 GTS that would have cost me over 270k with only few options that I wanted.

This is my 3rd SL & 2nd SL amg, I still have 2005 SL55 amg and yes, Mercedes could do better job before they released 2022 SL63. but I think this car has many characters in it that suit my driving taste -- it's like a having 3 different cars in one

Although, I wished all 4 wheels can be raised up like older ABS suspension, lower hood profile than what it is now and more solid thump feeling on door & hood but, I guess lighter weight design of this car & 4 wheel driven train design has to give somewhere

Good luck to you & your SL63!

Here is a video from a guy who really enjoys SL63