View Poll Results: Has anyone had this same type of problem?
Voters: 32. You may not vote on this poll
48-volt battery
Junior Member
Joined: Feb 2015
Posts: 27
Likes: 20
From: Bismarck, North Dakota
2018 E400 convertible
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.
MBWorld Fanatic!
Joined: May 2018
Posts: 3,391
Likes: 1,040
From: Boise
2024 GMC Canyon Denali..... 2018 Audi SQ5
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?
Senior Member
Joined: May 2021
Posts: 338
Likes: 101
From: Shaker Heights, Ohio
2021 E450 All Terrain Wagon
Spell check got you…if belles is batteries I don’t know when they changed batteries or even if they did. It’s just an assumption or maybe something I picked up talking to the Dealer. All we know for certain is that GLE 48 volts started failing with build dates of late September/ early October 2020 model year 2021 US. New battery PN seems to be the fix.
Senior Member
Joined: May 2021
Posts: 338
Likes: 101
From: Shaker Heights, Ohio
2021 E450 All Terrain Wagon
Thank you. That ruins a lame theory I was working on. It seems that all of the failed 48 volt battery reports on MY 2021 are basically the same: when it dies, the car becomes a 4,500 pound paper weight and needs to be hauled away on a flatbed (no way to charge or restart it); whereas, I thought some people reported they were sometimes able to get their MY 2020's restarted and sometimes even limp to the dealership. I was wondering what's different about the MY 2021 powertrain that might account for the difference.
MBWorld Fanatic!
Joined: May 2018
Posts: 3,391
Likes: 1,040
From: Boise
2024 GMC Canyon Denali..... 2018 Audi SQ5
Thank you. That ruins a lame theory I was working on. It seems that all of the failed 48 volt battery reports on MY 2021 are basically the same: when it dies, the car becomes a 4,500 pound paper weight and needs to be hauled away on a flatbed (no way to charge or restart it); whereas, I thought some people reported they were sometimes able to get their MY 2020's restarted and sometimes even limp to the dealership. I was wondering what's different about the MY 2021 powertrain that might account for the difference.
My best guess is that something was changed that created the failures…most likely in the circuit board that controls the battery functions.
Senior Member
Joined: May 2021
Posts: 338
Likes: 101
From: Shaker Heights, Ohio
2021 E450 All Terrain Wagon
Thanks for enlightening!
MBWorld Fanatic!
Joined: Jul 2003
Posts: 6,770
Likes: 1,264
From: Lake Oswego, OR
2020 GLE 450; 2023 BMW M2 Coupe
Battery warnings
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.
AFAIK there is no state of charge notice for the 48 volt…just a warning message in the DIC when it fails.
MB World Stories
The Best of Mercedes & AMG
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)
Verdad Gallardo
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
MBWorld Fanatic!
Joined: May 2018
Posts: 3,391
Likes: 1,040
From: Boise
2024 GMC Canyon Denali..... 2018 Audi SQ5
Let’s hope it’s the 12. There have been software updates so it’s possible that they have corrected the notice. I’m thinking that there isn’t much resource devoted to existing systems since the push is on new Electric variants.
Junior Member
Joined: Oct 2021
Posts: 21
Likes: 2
GLS 450
Super Member
Joined: Apr 2021
Posts: 645
Likes: 204
From: Central Indiana
2021 GLC 300 4Matic
GLE 450. I have stop/start on all the time unless I accidently turn it off. I toggle between eco and sport mode but drive mostly in eco. I do have the driver assistance package plus but only use the adaptive cruise. Unless I'm on a long trip, all of the other driver assistance features are turned off.
MBWorld Fanatic!
Joined: May 2018
Posts: 3,391
Likes: 1,040
From: Boise
2024 GMC Canyon Denali..... 2018 Audi SQ5
[QUOTE 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?[/QUOTE]
There’s no reason to worry about discharging the 48 volt battery, IMO. For one thing there is battery management built into the system to keep it from overcharging or complete discharge. The ISG does regenerative charging coasting and more when braking. It can also charge during normal driving as needed. In 2 1/2 years I have never turned anything off for the purpose of saving the battery. The GLE 53 uses even more juice running the 48 volt powered Electric Boost and the Active Sway bars and always has enough battery charge to perform as needed.
There’s no reason to worry about discharging the 48 volt battery, IMO. For one thing there is battery management built into the system to keep it from overcharging or complete discharge. The ISG does regenerative charging coasting and more when braking. It can also charge during normal driving as needed. In 2 1/2 years I have never turned anything off for the purpose of saving the battery. The GLE 53 uses even more juice running the 48 volt powered Electric Boost and the Active Sway bars and always has enough battery charge to perform as needed.
Junior Member
Joined: Oct 2021
Posts: 21
Likes: 2
GLS 450
Thanks Ron and MBGuy...
I have E-Active Body control, not sure how much it would use 48 volt system, so was worried if it helps to turn certain things off.
My build is 15th Oct 2021, so I guess battery should be new part number. I still can't get info with free vin decoder. I would have to ask Sales guy to get it for me.
Super Member
Joined: Sep 2015
Posts: 526
Likes: 203
From: Texas
2021 GLE 53 AMG Coupe
[QUOTE [color=#333333]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?
There’s no reason to worry about discharging the 48 volt battery, IMO. For one thing there is battery management built into the system to keep it from overcharging or complete discharge. The ISG does regenerative charging coasting and more when braking. It can also charge during normal driving as needed. In 2 1/2 years I have never turned anything off for the purpose of saving the battery. The GLE 53 uses even more juice running the 48 volt powered Electric Boost and the Active Sway bars and always has enough battery charge to perform as needed.
There’s no reason to worry about discharging the 48 volt battery, IMO. For one thing there is battery management built into the system to keep it from overcharging or complete discharge. The ISG does regenerative charging coasting and more when braking. It can also charge during normal driving as needed. In 2 1/2 years I have never turned anything off for the purpose of saving the battery. The GLE 53 uses even more juice running the 48 volt powered Electric Boost and the Active Sway bars and always has enough battery charge to perform as needed.
MBWorld Fanatic!
Joined: Jul 2003
Posts: 6,770
Likes: 1,264
From: Lake Oswego, OR
2020 GLE 450; 2023 BMW M2 Coupe
Battery charge warnings
Thanks for the bit of encouragement. Car goes in next Wednesday. No other symptoms than the warning, first by email advising to drive 30-60 minutes, which my wife did. Yesterday, unfortunately on the way to the ER for a torn quad tendon, the dashboard warning again advised of critical starter battery, and said to "pull over and leave engine running," which we did not do. Were able to complete our round trip.
Senior Member
Joined: May 2021
Posts: 338
Likes: 101
From: Shaker Heights, Ohio
2021 E450 All Terrain Wagon
I think better the 12 volt than the 48 volt. Either way though, I'm sure it's a big inconvenience to say the least.
Senior Member
Joined: May 2021
Posts: 338
Likes: 101
From: Shaker Heights, Ohio
2021 E450 All Terrain Wagon
MBWorld Fanatic!
Joined: May 2020
Posts: 2,838
Likes: 1,601
From: Florida
MBWorld God!
Joined: Dec 2019
Posts: 32,505
Likes: 6,347
Nice, quiet is good news for sure.
Newbie
Joined: Jun 2017
Posts: 7
Likes: 2
AMG GLE63S
Newbie
Joined: Sep 2020
Posts: 8
Likes: 6
From: Green Bay
GLE450
Took dealer 2 days to get it started. They (and Mercedes) claimed the batteries "tested good" so they only did a software update. It has been working for 3 weeks now but I have doubts how a software issue could cause these symptoms. BTW, I have an electronics background with 30 years of experience fixing/maintaining large mainframe computers. In my view, a battery change is needed in addition to the software change.
MBWorld Fanatic!
Joined: May 2018
Posts: 3,391
Likes: 1,040
From: Boise
2024 GMC Canyon Denali..... 2018 Audi SQ5
Well, it's not real quiet. Our 2020 450 GLE (15K miles) just died with total electrical failure. Could not charge or jump the car. Tow truck driver tried his battery pack and it sucked it dry in about 5 seconds.
Took dealer 2 days to get it started. They (and Mercedes) claimed the batteries "tested good" so they only did a software update. It has been working for 3 weeks now but I have doubts how a software issue could cause these symptoms. BTW, I have an electronics background with 30 years of experience fixing/maintaining large mainframe computers. In my view, a battery change is needed in addition to the software change.
Took dealer 2 days to get it started. They (and Mercedes) claimed the batteries "tested good" so they only did a software update. It has been working for 3 weeks now but I have doubts how a software issue could cause these symptoms. BTW, I have an electronics background with 30 years of experience fixing/maintaining large mainframe computers. In my view, a battery change is needed in addition to the software change.
MBWorld Fanatic!
Joined: Oct 2009
Posts: 7,016
Likes: 2,198
From: Colorado
'21 AMG53 wDPP & ARC, 19 GLC300 - Former-03 C240,2 ML BlueTecs,20 GLE450 E-ABC,15 Cayenne D,17 Macan
An important software update was done to my replacement battery when my 48 volt failed in May of 2021 and no issue since. I was told that the new software update was designed to prevent a similar failure in the future. There is a battery controller in the 48 volt Lithium to manage “State of Charge” and numerous other functions. One function “disconnects” (for lack of a better term) the battery in case of an accident to prevent a battery fire from a “short”. It’s possible that your battery was OK but a safety mechanism incorrectly disabled the battery function. I had a detailed discussion with the Shop Foreman and don’t recall the technical terms he used but that’s some of the layman’s explanation.
So there are two "Heads of (battery) State"
The car senses the need for power, or need for charge, and directs it to the battery. There IS a software contentment from M-B. That's what's updated.
Then the BMS takes over and its primary mission is to care for the battery. This might be preventing fires as @Ron.s mentions, plus it controls charge rate, may warm the battery when cold or keep it from overheating - there are lots of things Lithium batteries need to keep them healthy for a longer life.
The BMS is its own computer with its own software. IDK if the BMS software can be updated, but I wouldn't be surprised.
