ArchHist99

So I found out that a 48V battery would not be covered under extended warranty, because it is, after all, a battery. The cost to buy just the 48V battery from MB parts would be $1,390!! As I found out, when the 48V battery goes, you still have the electronics that work, but the engine won’t turn over. The batteries (12V and 48V) work together but the 12V can still work and keep the electronics and settings for a number of days(?) until the 48V gets replaced. The new 48V did have a newer part number than my original, and a software update does get done to basically tell the car there is a new battery installed. If the 12V goes, then it is like a regular car battery dying and NOTHING works - engine nor electronics. At that point you can’t get the car into gear and I am guessing it would have to be dragged or rolled out? The 12V is less expensive at about $300 to replace.

chassis

Thanks for the post, interesting. First to document that the high failure rate and expensive
48V battery is not covered by extended warranty. It’s a bitter pill, because a failed 48V battery bricks the car from a transportation point of view (engine won’t start).

Frenetic

It’s unfortunate that battery isn’t covered by any warranty. Most traditional batteries, even proprietary ones, have pretty solid “battery warranties” from the manufacturer. What Mercedes is essentially saying is that you can buy a new one and it can fail a week later and technically, unless they goodwill you, you’re SOL. That doesn’t seem right or fair in my book.

TonyF61

Yes, it is unfortunate, but to be clear, @ArchHist99 stated it is not covered under "extended" warranty; not "any". I believe that there are many posts in this forum where members had their 24V battery replaced under the standard warranty.

ArchHist99

Correct. It is covered under the standard 4-yr. Original warranty, but not the extended.

Frenetic

Yes, but what I was referring to was a simple standalone warranty that most batteries come with. Even most EV batteries have dedicated, separate battery warranties that far exceed the base warranty.

ArchHist99

Good point. That we’d need to ask MB or parts dept.

TonyF61

I don't know of any manuf. that offers lifetime warranty on battery. M-B is offering 4-year. In fact, I had a Lincoln MKS and the battery died less than a week after standard warranty expired.
The standard warranty will only last me two years due to the amount of miles a drive every year; therefore, I did purchase an extended warranty. Hopefully, there will be enough complaints regarding the 48V battery, that M-B will be forced to either recall, or more beneficial to them, quietly replace them free of change when they die. Fingers crossed!

Frenetic

I never said lifetime warranty. I’m talking about a simple standalone warranty that is typical of most batteries. Almost all 12-volt car batteries have warranties. Dedicated EV batteries have separate warranties. This battery, which is essential to the car just like any other battery, has none, zero, zilch.

Ron.s

All batteries are essential to the car since the car won’t start when they fail. A normal ICE without the 48 volt can be jump started if it’s just weak but probably not with dead cells. A lithium battery should last longer than other LA or AGM batteries. The failures of the Mercedes batteries aren’t likely the battery cell itself. There has only been one 48 volt battery failure reported on this Forum on the original early 2019 through Q3 2021 48 volt batteries. The failure epidemic seems isolated to Q4 2021-Q1 2022 give or take a few months. The 48 volt battery on my 2020 GLE, 450 built in early 2019, is still going strong with over 40k miles now.
EV batteries have longer warranties because of government mandates. The warranty on any replacement 12 volt battery is normally prorated so you don’t get a new one free.
If the OEM 48 volt battery gets a full replacement during 4 years vs prorated on one purchased that is a better deal. The fact that there is no battery warranty after 4 years doesn’t mean that a replacement battery won’t have a warranty.

Unfortunately we often don’t know the facts until after the purchase. Buy a used EV just before the warranty is over…have it fail out of warranty…find out battery costs more than car is worth in many cases. Hybrids are another beast with another set of problems.

Frenetic

Well, has anyone asked if that battery does have a separate warranty, mutually exclusive to the base warranty? One would think that for such an important item that it would or should at least be listed somewhere in the warranty section.

Anyone care to ask MB? I can when I have time.

TonyF61

It does have a four-year warranty. Under normal circumstances, I would be delighted with that. Most battery replacements are prorated. It is my understanding that this is not prorated, within the first four years, or 40K miles.

TonyF61

If it does, then that is great. If it doesn't, then nothing I can do about it. Therefore, I am not going to get worked up about a battery that may or may not malfunction, and may or may not cost me to replace it.

Ron.s

Well it went from the battery has no warranty, zilch, nada to maybe we need to find out! Rash statements are one thing…we all do it but it’s perfectly OK to admit a mistake, IMO.

It will be about 6 months before any GLE 48 volt batteries are out of warranty and Retail sales begin. Mercedes might not even have a warranty plan in place yet. As these Lithiums proliferate and longevity is more predictable in hybrids and EV’s, an insurance company or Manufacturers might start offering extended coverage for them.
Why is anyone with several years left on the existing battery warranty so concerned about a 2026 event? Costs may come down and component replacement could be an option rather than a new battery. A lot can change….

HotRodW

It would be nice to understand exactly what is covered under the warranty. I searched previously but wasn't able to find anything specific to the 48v battery. I did learn that the high voltage battery for plug-in hybrids are warrantied for 6-years/62,000 miles, although 'reasonable' capacity loss is expected and therefore would not be covered.

TexAg91

That is an interesting position that may be challengeable under US Law. Hybrid systems are part of the emission system (shut the engine off at stop lights to save gas and emissions), and under US Regs are warranted for 8 years…the 48 Volt system appears to meet the technical definition of a mild hybrid…even though Mercedes doesn’t call it as such. Not sure how their corp lawyers can justify that position, but apparently they think they can???

…and to proactively answer the obvious question, I base that on the following article:

https://www.kbb.com/car-advice/hybrid-ev-battery-warranty/

Of course, that doesn’t mean this is correct—one would have to actually find and cite the Regulation. Anyone know how to find and verify the authenticity of the kbb article — where are hybrid battery warranties address in US Law/Regulation? Then you’d have to show the GLE 450 meets the definition of a hybrid motor vehicle.

Frenetic

So I called up my local Mercedes Parts department and they said there is no separate battery warranty similar to a proration you might get for a premature 12-volt battery failure. I tried talking to my service advisor, but he was too busy, and I didn’t feel like leaving a message.

So, if you have a battery failure outside of the original manufacturer’s warranty, you’re SOL. Even worse, if you spend the thousands to replace the battery yourself because it failed outside of warranty and it fails again within a year, you’re equally and doubly SOL.

I think this was a very big oversight on Mercedes’ part. These cars are hybrids and these batteries should be covered like any other hybrid battery, which is usually very long (80k+). Yes, it’s a “mild-hybrid,” but it’s a hybrid nonetheless and this car cannot function without it. This makes owning these things out of warranty even more riskier as no warranty covers it, extended or not.

PandaSPUR

This was the first Google result when I searched "mercedes parts warranty":
https://www.mbusa.com/content/dam/mb...20Warranty.pdf

Frenetic

TexAG is correct. I just pulled and read the warranty disclosure and the 48 Volt is covered under the emissions warranty to 70 or 80k depending on your state, but it’s not covered under any standalone battery or hybrid battery system. So, there it is.

Neurobit

Guess what, if your engine/tranny/ECU/fill-in-the-blank part fails outside the original warranty, you’re SOL as well. What’s your point?

Frenetic

12-Volt Battery:
1. $200 to $500 maybe to replace parts and labor?
2. Typically comes with a five to ten year prorated warranty.
3. Required for operation.

48-Volt Mild-Hybrid Battery:
1. $1,500 to $2,500 to replace parts and labor? I have no idea, I’m just guessing, anyone know?
2. No standalone warranty outside of the manufacturer’s warranty.
3. Required for operation.
4. Documented cases of these failing within a year or two.

PandaSPUR

Are you just going to keep ignoring the MBUSA link I posted that talks about the 2 year warranty for replacement batteries on cars that are outside of the original warranty period?

Frenetic

I saw that but I also asked my dealer’s part department if that battery had any warranty and he said no. That document also clearly lists a separate 12-Volt battery section. I think this merits further investigation. I was going to call the dealership back and actually try talking to my service advisor or a manager.

If that document applies, great, but the information I got from the dealership conflicts.

PandaSPUR

I dont see where it differentiates between 12v or 48v battery.

You're probably better off just contacting MBUSA for clarification. It would not be the first time a dealership had wrong information.

Ron.s

Some people have a hard time admitting a mistake. This is still fallout from the “no warranty, nada, zilch” comment that had no basis in fact. The warranty is a valid concern for many owners but not for a person on record that they will not keep the car past factory warranty period of 4 years.