kenromero

How many of you are receiving that email message?
I've been getting the message quite frequently lately. I've taken it into Fletcher Jones, they had it for two days and returned it supposedly corrected. Yet one day later the engine light appears with many messages of non-operation displayed.
The check engine light went off the following day but the battery critical email comes daily. I purchased the CTEK trickle charger but it only lights up to #2 then the red light comes on. I also have experienced that the door handles do not pop out when I approach the car and have to use the key fob to pop them open.
I will take it back to Fletcher after Labor Day but wonder if this has been a common problem.
Thanks for responses!

iancoletx

Same issue here, I had to have someone jimmy the lock because I left the key inside with this BS low battery error so the door handles wouldn’t pop and the remote unlock wouldn’t work. Nothing but problems with this car since I bought it, first and last Mercedes

kenromero

Interesting, my neighbor has a 2022 S580 and the car wash person left the key inside, supposedly unlocked, and she could not get it open even with her 2nd key. They called AAA to open it.

iancoletx

you know what, I may eat my words on this one. I just got in the car and realized the second key fob was down in the crack next to the seat. I’m guessing maybe that was keeping the car active when not in use and draining the battery.

superswiss

I get this message occasionally in case of my C63 when the battery is indeed critical. It usually happens when it's in for service and they work on it for a while with stuff powered on. I text my SA when I get it and then they put it on a charger and it stops and the battery will soon show as fully charged in the app again. This is how it should normally work. It's been happening more often since I'm not driving the car much, so I now make sure to charge the battery the night before I take it in and then it's usually fine.

If you do get it with normal driving even if you don't drive all that much (I mostly drive on weekends), then something is up with your battery. Unfortunately, I've been told by my SA that MB has made it extremely difficult to get the battery replaced. They have to run a very specific diagnostics test now and MB only authorizes a new battery if it fails that test, and apparently it's very difficult for a battery to fail the test. He told me even cars that are towed in with a drained battery often still pass the test, so all they can do is charge the battery and send the customers on their way. I've noticed that my trickle charger started indicating that I had a bad battery, although I don't have any other symptoms. When it happens I unplug the trickle charger and then plug it back in and then it finishes charging the battery. Not sure what's going on, but as expected it past the diagnostics test, so they wouldn't do anything about it. It may just be the charger.

The key fobs have a motion sensor and go to sleep after 2 minutes of not sensing any motion, so no they won't keep the car awake. I've parked all my cars unlocked in my garage for many years with at least one key fob nearby and this never drained any battery.

kenromero

Thanks for the reply. It seems odd MB would not replace the battery. It would seem that would be far less expensive than repetitive warranty visits to the dealer.

kenromero

Does the car’s computer store the time, date and error code when the engine light goes on?

superswiss

Yes, as far as I know error codes are timestamped and there may also be a freeze frame that goes along with it showing other data such as rpm etc. at the time it happened.

kenromero

Thanks, I'll mention that to the service advisor next week. I take it in Thursday morning

crabman

Not the case with the new S Class. The car will not fully shut down at long as it can detect a fob and it won't stop detecting it, even overnight. Numerous people have had the problem, I'm among them. The door handles are a clue to this as well. They have a time out function that causes the handles to retract if they're extended and will prevent them from extending in the first place if the car is in contact with the fob too long. The battery messages stop coming and the handles start working as expected if you lock the car, and get the fob either far enough away it can't be seen by the car, or bag it to block the signal. Those can be bought on Amazon or you can make your own.

Lots of people have run into this, it's counterintuitive because it defies what you know about fobs and how they work but it's a thing with the 223.

kenromero

Thanks Crabman, do you know how far the fob should be from the car when parked in a garage? My key is probably only 10ft from the car. I hang all car keys by the garage door to be easily available when leaving.

superswiss

None of the cars fully shut down. The door modules always stay powered unless the battery gets low., and if you lock the car the alarm system drains power. The only difference is that with the S Class you realize it because of the retractable door handles, but in other cars the door modules stay active as well, so that they detect the fob as soon as it comes in range. When I had a W223 loaner I treated it no different. It stayed in my garage unlocked for several days w/o any issues. Maybe some early models have bugs, which wouldn't be a surprise with how not fully baked the software is in many recent cars.

In addition the telematics and data connection stays active as well, so that you can remote lock/start it at any time. So there is always a certain battery drain and if you have a weak cell signal in your garage then the drain is even higher as it has to boost the signal. Some models have a standby mode now to fully shut them down. I use it in my car when I go on vacation. It turns off all the consumers that stay powered otherwise such as the telematics, data connection and the car alarm.

vladfein

I had a few messages in a year-and-a half. Last three - within a month. The car is in service now, they are waiting on the "engineering" response.
I can attribute the last two (or even all three) "critical battery" alerts to not driving for two-three days at a time. My keys are in the house, not too far from the garage - is that a problem?

crabman

True dat but not what I'm talking about. This car will not attain its normal shutdown with a fob in range. Error codes that should reset when the car shuts down will not reset. The car will not go to it's correct shut down state and power will be depleted more rapidly.

The car must be locked, the fob must be taken out of communication with the car. LOTS of 223 guys have been there: Do this and the doors start working as expected. You stop getting the power messages. The low tire pressure warning that never clears (or any other that should clear on a power cycle but doesn't) will clear because the car will fully shut down where before it would not. It's a thing.

I think the last guy was @Frenetic with this but many have been there, I've been there.

Best bet for convenience is to cage it, also helps prevent theft so it's not money wasted on the next car. Because it's possible you may actually have a fault with the car I'd test first. It's easy to make a ghetto faraday cage with items you have around the house. Use it for a few days and you'll know if car-fob communication is preventing your car from fully shutting down. Like I said though, the handles acting funky is a strong clue that the car is being kept awake.

superswiss

Sounds like a bug.

crabman

The door handles retract, and don't automatically extend again until manually deployed by design. The rest of it, yeah, no way it's an intended behavior. Still, until such time at it gets fixed in an update, this is our way past the issue.

DonS550

Try moving your key fob further away from where the car is parked. I guarantee this will alleviate the problem.

kenromero

Thanks, I will try that.

superswiss

You can also simply deactivate the key fobs. No need to move them farther away or to put them in a makeshift faraday cage.

kenromero

Thanks for that advice, I never thought of deactivating the 2nd key which we store in a cabinet fairly near the key in use. Great way to store a 2nd battery.
I shoukd go through the user manual!!

rnpalmer

Went to start the car last Thursday and nothing worked. I had to call Mercedes emergency services to tow the vehicle to the dealership. I too have had multiple critical battery warnings for both the 12v and starter battery on Mercedes Me and on the dash. There is also an over the air communications software download that will not install. I have brought the car into dealership three times but they keep saying the battery tests ok. I was offered a trickle charger for $600 which I found absurd. Has anyone found a solution to this battery problem? Is there a recommended aftermarket trickle charger you'd recommend?

kenromero

I purchased the CTEK trickle charger on Amazon. Looks like the MB charger.

crabman

Keeping it simple is how we got to the moon 50 years ago. Get your fob out of communication with the car to see if that's the problem. It usually is the problem. Because many people don't have any good place to put a fob out of range of the car the easiest way to solve the problem (if this is the case) is to use a cage. You don't have to remember to turn the fob off, actually do it, or even think. Mine is by the door on the way out. When I leave, I grab the fob. When I get back I drop it in on the way by. I'd be sticking it someplace anyway, it is not an extra step. I don't have to turn the fob on, I don't have to turn it off. No effort, no thinking, no problems.

Streamliner

Read my thread “MY S580 STRANDED ME!”

kenromero

I did! I was afraid mine would stop while driving also. I took it into Fletcher this morning. Looking at the MB app, they still haven't started to look at it yet now 5 hours later.