I'm thinking of changing the starter battery (main battery) in my 2018 GLC300. I was considering an Optima or Diehard. Does anyone know if the battery needs to be coded or registered to the SAM or OBC? I see conflicting information about this on the internet. Any help would be most appreciated..... Thanks in advance

<Said jokingly, as a former BMW driver myself> "This is what happens when a former BMW owner finds themselves driving a Mercedes."

Kidding aside, I don't recall any type of programming for a Mercedes battery being necessary -- just replace with comparable battery, using all of the proper safety protocols and leave the registration to the blue/white team drivers...

That said, my experience with Mercedes is that most have too little space under the hood for my hands, so wear gloves to save yourself from scrapes, and most importantly, have a cold one nearby to open up AFTER the job is done.

Follow up: Battery replaced with an Optima yellow top. No issues. No programing needed. I didn't even use an alternative power supply to make sure I don't lose any memory settings. I just pulled and replaced the battery. Everything works fine and the memory settings all retained....

Just curious. ...
why did you feel the battery should be replaced?

It's my wife's car and she kept getting the stop vehicle, leave engine running with the battery icon coming up on the DIC. Despite charging the battery twice and the first time for 24 hours and the second time for 48 hours, the warning came back the following day. I took the vehicle to Advanced Auto and they performed a battery diagnostic on it and they recommended replacing it. So I did. The vehicle is an early 2018 and has 42K miles and batteries usually don't last longer than 3 years in South Florida climate either.

Fair enough....
I've never had to replace a battery in 3 years. 5 years would have been the minimum on any car I've ever driven.

Florida heat destroys batteries so fast. Three years is a pretty good amount to get out of them.

Well I've learned something new today!!
I thought it was cold that was hard on batteries! !

Not trying to second guess you, but why not replace with OEM battery under warranty? Or are you beyond 48 months or did you simply have a preference for the Optima?

Warranty expired and this is a very good battery and cheaper than OEM. Saved 100s vs going thru dealer too. And I didn't have to spend all day at the dealer either

Yes the battery needs to be registered/reset. There is a charging counter that will continue to run if not reset. Apparently the system increases the charge for older batteries potentially overcharging newer batteries. I just topped off my 2016 GLC300 battery with a maintainer since I got the start/run engine low battery warning. Did the same thing last year. Contribute this to little or no driving with COVID. The Foxwell NT530 for Mercedes supposedly will register/reset a new battery. They are $169 on Amazon. Local independent shop wants $125, an hour, to code a battery. Should take 15-20 minutes at most.

I had the new battery in my wife's vehicle for a few weeks now and I don't see any problems with it... I'm surprised that there isn't very much information pertaining to this on the internet or much feedback on this forum about this either. Thank you for your reply. I am going to look into purchasing this OBD Diagnostic Scanner. It's probably good to have anyway.....

Edited

This scanner is listed on Foxwell support site as supporting the following BMS (Battery Management System) functions for X253 chassis: ECU Information, Read Codes, Erase Codes, Live Data. Do you know which one of these 4 manages battery registration?

1st. Check the factory warranty. If it's not cover by warranty. It's will costs $1,000+ to replace battery in the dealer.
​​​​​​I just replaced Optima yellow top DH6 CCA 800A in the Advance Auto Parts to my 2016 GLC300, they use backup battery to plug in the ODB port to keep memory, battery $315 and received 20% off only $250. It took only 10 minutes to replace it very easy. Labor is free no charge.
BTW The Auto Start/Stop was not working after 2nd years I bought the GLC and went back to dealer many times and a lot of dealer excuses and never fixed and I just leave the problem there till last week I replaced the battery and Auto Start/Stop back to normal. The Mercedes OEM battery quality is very bad, I have 3 friend bought GLC after me, 2 2017 and 1 2018 all 3 got the battery light on this winter. Very bad quality never buy OEM Mercedes Battery. At least Optima battery comes with 3 years warranty.
Optima Yellow Top Deep Cycle Battery, Group Size H6, 800 CCA, 925 CA, 140 RC Link

Not sure where 1000$ came from, i replaced main batter in ML at the dealer. Main battery in ML located under passenger sit, access is PITA.
Cost was 450$ total.
GLC battery right up from with easy access, cost should be the same or less, as less labor and smaller battery.

The car does have an adaptive charging system, that puts less and less stress on the battery as it ages, by not charging it up quite so full. So if you replace the battery and don't run the reset process, it will continue to charge it at the decaying rate, leading to less life out of the replacement battery also.

How is your 2018 out of warranty already?

Any pointers on how to run this reset process? Is there a non-MB scanner capable of this for X253? Thanks.

I've owned numerous corvettes and I've had to change batteries every 2 years down here in this extremely hot climate.

I just got confirmation from my friend who is service manager at Mercedes, with GLC you have to do nothing, no reset or registration.
Simple battery swap.

Yup, heat kills battery!
My wife's Infinity kills them every 3 years! My GLC is 4 years old and I am thinking about replacing the battery. But will wait a bit...

LOL You took the words out of my brain. I had just thought this guy used to own a BMW....ask me how I know??!! LOL Just another reason I love Mercedes...easy to work on and maintain, your not hostage to them like BMW.

Just replaced my batter in a 2017 GLC300 and looking into this registration due to the charging of the old battery and it shortening the life of the new battery.. Some say it’s not necessary and others say it is, any chance for an update and some clarification?

MBenz has no formal battery registration like BMW do.
The ECU software tries to learn your MAIN battery to charge it well... just like ECU does for engine and TCM for gearbox.
Energy Mgt is done by sensors and computers hosted throughout the car from from ECU to Rear-SAM.

The one thing you can do is unplug the sensor control wire from the Battery (-) post. It will cause the engine computer to relearn its battery condition with more charging efforts in the 14.x ballpark instead of 12.6v float voltage. You can do that at anytime with both [Engine + KEY]= OFF, old or new battery.

Benz modern multi-stage dual battery charging is an amazing source of repeat service. Every Benz driver is bound to learn about it one way or another. The best thing you can do for your batteries is to float them with a CTEK or equivalent as often as practical... like once or twice a month. This easily helps lower 80Amp charge currents that end up damaging alternator, batteries, PreFuse and both SAM's... none of which come cheap with diagnostic fees: $2k.

This version is my no-brainer DIY to address this sticky mess.

This detailed information you shared - where is it coming from and is it valid for X253? Check the attached WIS document on battery replacement, specifically Step 13 "Confirm battery change in front SAM control unit in the Actuations menu item". The second attached WIS doc has more details.

Reading them together, I think registration *is* required - unless someone can point to specific *documents* stating otherwise. Everything else is just hearsay and opinions.

Anybody know of any DYI-level OBDII device capable of updating SAM? That would be very helpful for this community to know.