Longroof45

I should add that the the member originally posting on "48 volt battery problem? Check in here." is trying to create a single site where everyone who has experienced a 48v battery failure can register, with the end goal of having a single clearinghouse. However, that may be like herding cats.

marchgroupinc

Important that every 48V failure gets reported to the NHTSA for USA and Transport Canada for Canadians or there may never be an official MB recall.

Longroof45

Good suggestion. I have just reported my incidents with the NHTSA. While my car was, fortunately, at home when the failures occurred, they could have happened anywhere, including in the middle of a highway, or in the middle of nowhere in dangerous weather. Being apprehensive of those types of conditions, I actually cancelled a road trip from Ohio to Florida, opting to fly instead.

ghostx83

Yeah, I just filed a report with NHTSA. The SA called back and they did the software update and the car is running which I'm reluctant.

Longroof45

Just a software update and no battery replacement?

ghostx83

yeah, no battery replacement. Not sure why... I told him the battery should be replaced and he said it was not needed based on the shop foreman.

TexAg91

The 48 Battery SOC is computer controlled. So don't underestimate the power to software to screw things up, or to preemptively shut things down if the sensors and code thinks there is a problem.

mikapen

I agree. The only time engines used to shut down was when they ran out of gas. My, how times have changed!

I have an associated question.
It's my impression that most (all?) Lithium Ion batteries have their own internal charging software. Can a M-B software update also update the battery internal algorithms? Does it need to? Can they compete?

I would think that they run independently of each other, so you could buy any battery that fits the spec and it would work. I hope.

TexAg91

It depends on the software architecture, and how much Mercedes trusts the over the air updates. Usually software is divided into tiers, and the highest tier is anything safety related. It goes through the full gamut of regression testing and is strictly controlled and I doubt Mercedes would want to update anything safety related over the air. Anything non safety related would be fair game, so I would think it would depend on if Mercedes considers Battery management safety related. It probably is due to Lithium being flammable and the potential for thermal run away...but this is all just conjecture on my part.

Ron.s

Good questions-I know all Lithium batteries have battery management software…one standard piece is “state of charge management” to keep the battery from discharging completely or from over charging. I’ve seen a video of the Controller card in Mercedes batteries that looks like a mini computer motherboard. It must do more than just manage a few simple things like state of charge…probably integrates with the ISG to some extent. Mercedes batteries are many small individual cells and they are temperature controlled so that temp management probably resides on the controller.
Logically one would think that they designed the system to program the battery Controller from the OBD port but….

Longroof45

Thanks to the three of you. This is like a master class in powertrains. I'm actually learning something.

marchgroupinc

We have said it before, but just in case MB is checking these comments WE SHOULD HAVE A VOLTAGE GAGE THAT MEASURES THE 48v BATTERY STATE OF CHARGE ETC. We could prevent some of these emergency situations potentially and make our 48v batteries less problematic.

Longroof45

Absolutely! And I do hope someone from M-B is monitoring this site because too many dealers are acting like it's a big surprise when the 48v fails.

timmahla

Hello All, I am new to the forum. Had been following 48v issue since about a month. my Car is due for delivery in 3 weeks and was wondering if anyone has seen issues with Sep or Oct 2021 builds?

MBguy013

I have a late June '21 build with no issues and nearly 5000 miles.

Longroof45

I've been following the 48v battery threads pretty much from the outset. Unfortunately, I haven't been able to detect a pattern. My first battery died at less than 200 miles but I've seen other cars with similar build dates (April 2021) die even after 5,000 miles.

Ron.s

There are two part numbers for the 48 volt listed previously on this Forum. After my replacement battery was installed I made a trip to talk to the Dealer Service Manager. He told me that along with the replacement battery that he also installed a software update “that would keep it from having a similar failure again”…his words. I asked about the 48 volt battery again at 10k service and he said that there have been no similar failures with the replacement battery. I trust his word…he’s a no BS, no excuses type of person with several “top 5” Mercedes awards from training seminars. In hindsight, I wish I had asked more questions about the reason for the failure.
My assumption is that Mercedes had a battery fix sometime in Q1 2020 but batteries were in short supply and take some time to build in sufficient numbers for new builds and as replacements for failed ones. During the transition in Q2,Q3 2020 they apparently continued to use some of the problematic batteries. My May 2020 48 volt replacement battery has 6 months and 7k miles now. My 2020 GLE 450 is 2 1/2 years old and has not had any battery issue to date. The new owner loves it.

timmahla

Super thanks MBguy013 for reply. Do you run ur with all tech on or anything you keep it turned off? Like Auto Start Stop turned off? or anything which can chew up a lot of battery which can be turned off?

timmahla

@Longroof45 Super thanks for being so active here. I had read so many of your post and they had been very helpful. I just wanted to say thanks for your time here.

timmahla

Thanks Ron, once again read your post as well.. So much informative.

Up here did you mean to say your May 2021 has 6 months and 7k miles? Whats the part number for new replaced battery?

I have VIN number for mine. It should reach dealer in 3 weeks in Australia. However when I try mbdecoder website, it does not show any info for that VIN. Do you know any website which would have info on new car VIN number?

Longroof45

Thanks! Glad I may have been able to help a bit.

GregW / Oregon

Well, after 31 months & 22k miles I thought I was immune, but got the “Starter batter critical” message twice in last 2 days, today while driving even though my wife drove it 45 minutes yesterday. This is how it often starts, right? Will get it in as soon as I can.

Ron.s

I think your 12 volt is going bad…not the 48 volt. I had that message with my 2020 and that’s what it was. My early warning was also the leveling feature working randomly after driving for a few miles. The 12v ran down while sitting (probably internal short) and then began to charge back while driving. It says starter battery because that’s the 12 volt in the 350 and prior Gen’s. Sloppy on MB’s part to not change the language since it’s been 3 years.
AFAIK there is no state of charge notice for the 48 volt…just a warning message in the DIC when it fails.

Ron.s

That’s the time and mileage since I got the new battery…now almost 7 months and 8k.
Old Battery-000-982-68-14. New Battery-000-982-67-14
Note the new battery has a lower PN so it’s possible that they went back to the trouble free battery used in the first Gen GLE 450’s. (Year designation 2020 US-2019 Europe)

At this late date you almost certainly have the new battery. Your Dealer Service Dept. can more likely run your VIN breakdown this early after production. The VIN decoders seem hit & miss.

Longroof45

That should make Greg W's day! Yes, I can attest to the fact that there is no warning when the 48 volt goes, at least I never received one; although MercedesMe Connect indicated that the 12 volt is critical, even though it was the 48 volt. Ron, is MY 2020 belles like MY 2021?