Wife got an email ostensibly from Mercedes saying the starter battery charge status was low and that she needed to drive for 30-60 minutes.

is this legit/normal to get these messages from Mercedes and if so, is this something people have seen in the past?

 

Yes. It says what it means. Happens if car has been sitting for a while or if doors and lights open for extended time like when car is getting serviced or detailed. If it happens more often or after doing what it says, the battery may be dying and needs replacement.

 

I often wondered about that. My Mercedes App always shows my battery partially charged. instead of "Okay" like everything else it checks.

 

I hate the partially charged in the app. I have a trickle charger for when I don't plan to drive it much or have not driven it much.

 

Any longer than the day after I have put a charger on it it reads partially charged. I have yet to see the "starter battery low - drive for xxx" message though. I asked the SA about "partially charged" in the app when it was in for service and he said it was fine. He told me not to worry about it unless it gives a message in the car. I did drive it afterwards with the workshop enabled and it reads 14.9V and shows it charging during the drive. Whenever I check voltage after it has been parked it is about 12.2V. After being charged it will read 12.8V. I use to have a 21 450 and on the information screen it showed the battery voltage with the HP and Torque but the AMG does not display the voltage on that same screen for some reason.

 

I've been traveling for around 4 weeks and mine still says partially charged even though it's on a 4A charger. I know it's fully charged though because the battery meter always says 14.1v or around there upon my return from long trips. Showing actual volts and only notifying low battery when close to the point where you can't start it, would be a lot better. The partially charged label is pretty useless. I just sent them a comment about this using this email:
me-connect.usa@cac.mercedes-benz.com

 

I have a GLE35 2020, 46K Miles. You battery is dying and driving around won’t fix it. Got this message 2 months ago, then a month later battery died and had to be replaced. Warning, you can’t change it yourself, the battery is under the drivers seat which must be removed. Recommend you schedule a service appt. When I finally had to jump-start my GLE we took it to service and they confirmed it was end-of-life. Hope this helps you

 

Okay, this seem to be a common thing. so I won't worry as much. Thanks for the info guys

 

Yes. Try using a trickle charger.

 

Drive the car for 60 minutes to charge the battery -- nobody can say MB lacks a sense of humor.

 

No matter the car, brand or type of battery, that's what it takes to recharge a battery.

If you ignore the "partially charged" warning, you're shortening the battery life.
If you wait until you see "critical," you're approaching not being able to start the car and you have hurt the battery. You need to charge immediately if you're critical.

A point to make, again for all cars, is that if you only make short trips, you will be gradually discharging the battery. It's also hard on the engine because you don't get it fully warmed up. True for all cars.

Add the additional load of being in the listening mode at all times - waiting for downloads, waiting for you to approach with your key, reporting back to Mercedes Me - there are a lot more electrical demands going on while car is just parked.

Someone earlier mentioned a trickle charger. That's another No-No. You need a battery maintainer, which senses state of charge of the battery and will stop charging when it's full.
Trickle chargers will just reach overcharge and continue to overcharge, shortening your battery life on that side of the equation.

IMO it's not funny when I have to replace a battery that should last 7 or 8 years, but I've killed it in three.
Just saying....

 

Get one of these to maintain your battery.

https://www.victronenergy.com/charge...t-ip65-charger

$130 on Amazon for the 10a version

 

This is what Mercedes rebrands and sells through parts. I have two and rotate them to 'those in need.'
CTEK - 40-206 MXS 5.0 Fully Automatic 4.3 amp Battery Charger and Maintainer 12V
https://a.co/d/fap6Y4w

 

Somewhat misleading, unless you're talking about the 48V battery. The 12V battery can be charged via the terminals located in the engine compartment. Even the 12V batteries don't fully charge, even after a long drive (I've read about 80% is the normal "full charge"). People tend to use the term "trickle charger" interchangeably with "maintainer", despite "maintainer" being the more accurate description for the preferred charging method. Any one of several quality "maintainer" brands will do the job if they have an AGM setting (which most 12V batteries now are). I have several Noco maintainers (1A and 2A) and a Noco 10A charger. All work just fine keeping the 12V batteries in all my vehicles charged when necessary, no matter if it's only for a couple weeks or on my X7 that I store during the winter months. There's no question contemporary cars never sleep -- there's always a bit of keep alive current being drawn from the battery, and I suspect there are episodes of larger current consumption when the telematics and other systems periodically wake-up, even when the is parked and off.

All the car manufacturers try to keep owners ignorant of the batteries and charging requirements. Some vehicle brand 48V batteries can be charged through the 12V system, but only when the hood is raised (for whatever reason), while others apparently require regenerative braking. The funny part in this is that the 48V battery is part of the fuel saving mild hybrid technology, and the fuel savings evaporate when you're making hour-long battery charging trips once a week.

 

What vehicle do you have (your info says 2014 GL)? If a V167, a discharging 12V battery can give that message. My 2020 started giving me that message in year 3. After a couple dealer visits a fault was diagnosed and the battery was finally replaced just before the warranty expiration.

 

very interesting. My 2021 450 just began showing "partially charged" today.
Will see if it corrects with drive around.
Service is booked soon.
50,000 kms on it

 

Battery charge level/percent is an inexact science. There are too many variables to reliably determine SOC without going through a full charge cycle (full discharge -> full charge). Estimations can be made based on the no load voltage and anticipated capacity but they are only estimations. As batteries age they will naturally loose capacity and depending on the method used to estimate the SOC this may be represented as the battery not "fully charging". If the battery still starts the vehicle it is fine. Service centers will of course be happy to sell you a new one and charge for the install. Batteries are "wear items" and not typically covered under warranty.

 

I agree that variables exist, but the ability to spin an engine isn't diagnostic at all.

I trust the "partially charged," and especially "critical" advisements.

If the battery is "partially charged," it's life is being shortened, just sitting there, hungry for electrons and ruining the plates.

Charge it! Either with a lengthy drive as suggested, or a battery maintainer.
You'll save money by extending its life, and maybe a roadside assistance call.

You're right that you can contibute to parts stores' profit lines by not taking care of your equipment, though.
It's like keeping your tires inflated correctly.

 

I suppose I am suspicious that the "partially charged" notice is very conservative and likely only represents the capacity loss of a four year old battery rather than anything that would require a service visit. It would be great to actually see the resting voltage and voltage drop on cranking to make a better determination that simply taking the word of the place that will likely be collecting a profit from replacing a "partially charged" battery.

 

My 20 GLS 12v battery stays on Partial Charge with my daily driving. It will show Charged if I am on a trip, but then only for a day or so. I’ve only had the Critical notification once. I bought a 22 Honda Ridgeline truck in March and did not drive the GLS for about three weeks. Loaded up for a trip and received the critical notification email. Started fine and was back at Charged when we reached our destination that day.

Not to hijack thread, but what is the typical dealer charge for a 12v battery? Battery in my GLS is original and nearly 4.5 years old. Monday received a “service specials” email from the dealer that included a 12v battery replacement for $462 and was just curious if this was a good price. If so, might take it in for recalls and proactively replace the battery. Thanks.

 

I see two solutions.
1. Do a load test before you replace the battery.
2. Charge your battery.

I have a 5-year-old battery in our GLC. It seldom leaves a 3 mi radius (wife's errand car), and therefore displays a "partially charged" notice every two or three weeks because of the short trips. If we ignore it (don't check the app) it goes critical in another week, and it sends an email. But, since I do check the app regularly, I apply the CTEK maintainer and bring it to a full charge.

The shop did a load test at 54 months and it was fine.

I think the displayed warnings added to the life of the battery, because my wife now participates and hooks up the CTEK maintainer when she sees "partially charged."
Triple win.

 

Since I don't really like to wrench, I think that's a good price. I believe most charge around $700.

Here's a video of a DIY:

 

Unplugged my car last night and this morning it says CHARGED.

 

did some driing yesterday about 30 miles. My GLE shows "charged" now on my Mercedes Me app. So basically, you have to drive them at least every 3-4 days.

 

Dealer here quoted $820. The seat, carpet, pillar etc has to be removed and reinstalled