I got a warning message tonight on my phone when the car was out and about, saying the battery was low, etc.... something to that effect. Built in 2018 that puts her at 4 years, so time for a new one. The rest feature was being used at the time, so that is interesting to know! Interstate batteries actually does not list this vehicle either does costco....LOL Usually I up to the highest CCA available, but will also look at the reserve capacity as well this time around, anyone use an Interstate battery as a replacement? What model number is it as well if anyone knows thanks

 

I believe it's either an H6 or H5. If you have an Autozone, I'd try the Duralast Platinum battery. I've had really good success with them over the years in various vehicles. I'm sure other parts stores have them also.

 

Four years is pretty soon for an OEM battery to fail. "Low Battery" doesn't mean "Need Battery."

It likely means that you haven't been driving your car enough to keep it fully charged. The Owners Manual, and sometimes the dash warnings, tell you to "drive for 30 minutes."
That's nowhere near enough to bring the battery up to full - in our case it took a few such drives to get over that "Low Battery" repeated warning. Once we did that, and quit taking short hops, we have never seen the warning again.

Similarly, as with all cars, those short hops are not only bad for batteries, but bad for Catalysts, Exhaust systems, oil life, and plenty of other things. Be thankful that Mercedes warns you about the battery - it may prolong your entire car's life.
Again, this is true for all cars.

Drive around for a bit, then get your battery Load Tested, before you start thinking about a replacement. Those OEM batteries are pretty stout. I usually get about 6 - 8 years out of them.

 

Mine lasted exactly 4 years. Except for the 4 months it sat at the VPC. My low battery warning took 3 days to reach need battery state.

 

Invest in a quality ‘intelligent’ battery charger. We use a brand called CTEK. Make sure the charger has ability to select type of battery you want charged. You will need one that allows AGM setting for your battery - this ensures the correct boost and trickle charge is applied for AGM construction.
Your GLC and alternator will never fully charge your battery, only to around 80-90% due to voltage limitation of car.
Charge your battery, leave it in place in GLC either for a day or overnight, say once a month. You will avoid strange system errors and shutdowns with certain components.
You will extend your battery life significantly too.

As another consideration is buy a portable battery jump starter for a 3.0l diesel or 6.0l petrol capacity, charge it up and leave it in trunk, diary an overnight recharge of jump starter every 9 months. perfect to restart you of a friends car without waiting for roadside service. There are some small units around the side of small carton of cigarettes or Bluetooth speaker.

 

at 50k service (little over 4.5 years) they tested battery and said it failed test and needed replacement. may have been god for a while longer but i figured while its there i would just have them do the work.

 

Are you over 50k miles (or over 4 years since delivery)? If not, you're under warranty and if it fails the battery test at the dealer they will replace it under warranty. I also agree with the above, it may just be weak from short distances / less driving since COVID, in which case it MIGHT not need to be replaced.

Personally, I don't really trust the battery testing analyzers the dealers and other stores use (Midtronics). I've had two instances where batteries failed about 2 weeks after having my car serviced (for unrelated reasons) and they showed me the battery test printouts at the time (one Acura that was in warranty and the other was a Mercedes that was out of warranty). Both dealers basically said a battery could pass the test and die the next day (which makes me question the true value of their analyzers).

However, whenever I've complained about a battery starting issue they've always replaced the battery under warranty (one was the Acura mentioned before, and the other was another Mercedes that was a low mileage CPO and the battery died at about 25k miles, just before 4 years old). Both work orders said "Customer states car needed to be jump started", and the report said something like "Tested battery - battery failed test - replaced battery".

If you're out of warranty, read on...

Based on experience researching batteries for the different Mercedes I've owned over the years, almost all of the AGM batteries you'll find under the different brands in the USA are made by the same OEM manufacturer and have exactly the same specs (in the same size, of course). For example, if your car takes the H6 (aka 48) AGM battery, compare the various options, such as:

• Champion (from Pep Boys),
• Die Hard Platinum (Advance),
• Duralast Platinum (Autozone),
• Ever Start Platinum (from Walmart) and
• Interstate (available from Costco and in many independent shops)

All of the above appear to be from he same OEM manufacturer (Johnson Controls, I believe). Look at them on the various web sites -- they are all the exact same casing, with the same handles, encased in perhaps in different color plastic and with different stickers. They all have the exact same specs (760 CCA), and nowadays they all seem to have the exact same 3-year warranty (those used to differ). Costco will be the cheapest, up to 30% lower cost, but not all clubs carry the H6 (or the H8 aka 49) sizes that most Mercedes use..

The Optimas may be different -- they look different and have slightly different ratings -- not sure they are cost justified in our cars for 800 CCA vs. 760CCA for the others.

The original batteries in the cars might be different -- used to be VARTA or another European brand, but not sure what the more modern cars use as my 2020 has a plastic cover on it. Some people have said even the dealer replacement battery is the same as the other aftermarkets here in the USA (as it's not worth shipping car batteries from Europe), so that's another reason why many of us found the original batteries to be the best (often lasting 7 years if car is garaged)..

 

After changing the battery, you might need to confirm it in SAM. The procedure was required to be done on pfl GLCs to help protect the new battery, not sure if it is still required for the facelift. Please see attached two documents.