Anyone know the part number, or specs for the “starter battery” on a 2022 G550?

Mine shows the message here, that my starter battery is low. It does this every few weeks. I then put it on a tender and it stops showing. Then it comes back a few weeks later.

I took into dealer and they ran diagnostics and could find no issue with battery (at least not enough of an issue to justify a warranty replacement).

I’m not sure if this is the primary 12V battery or if it’s a companion accessory battery. Since the message says “starter battery”, I presume it’s not primary one but don’t know with any certainty.

 

Do you park your car outside? Seriously, wind can cause that. I wish I was joking....

 

I do park outside, but there's almost no wind where I am in Austin, TX. Lots of sun/heat though.

 

Had the same issue, took it to the dealer and they just went ahead and replaced the battery. Never have had it pop up after that.

 

Whenever I've had that message I do the same--battery tender under the hood and the message goes away. I believe it is referencing the 12V battery in the trunk that you can charge from the posts under the hood.

I'll get the message when the car sits for awhile or when I first get it sometimes.

 

thanks. yes I had suspected it’s the main battery in trunk as that’s what the tender connections charge.

I’ll do the same and just replace that same battery if it persists.

 

For a 2022 G550, the starter battery is almost certainly the main AGM battery in the engine bay. The part number is Mercedes A0009825108, but you should always double-check the specs on your current battery to be sure.

That recurring message points to a drain or a failing cell, not the battery itself. Since the dealer cleared it, the issue is likely a parasitic drain from an aftermarket accessory or something that isn't drawing much while the car's at the shop. A specialist with experience in Mercedes electrical systems would be your best bet to track it down.

 

My '19 G550's battery failed at 42 months, so your battery might need replacing. No magic -- it's an H8 size, ~100 amp-hr, 800-900 CCA battery available at any auto store if a dealer is inconvenient or non-competitively priced. I bought an Autozone Duralast Platinum for about $240. Takes 30 minutes to change.

 

Yep, I got my last one at WalMart...rumor is they are all identical. I figured that if something happened in the warranty period (3 years) there would always be a WalMart nearby.

 

Not sure if they're all identical, but most of them come from three major battery manufacturers with private branding. I wonder if there's any real difference between batteries with different warranty periods. When you pay an extra $100 for a 36 month battery, is it different than the 12 month battery, or are you simply buying an extended warranty?

 

I just keep the car plugged in if I know I won't be driving it for more than a couple days.

 

I drive my 2024 AMG G 63, mostly around town, almost every day. I started getting those "low battery" alerts on my Mercedes Me app a few months ago. The truck always starts without any problems, but the "low battery" messages was a concern. I took it to the dealer to check, and they told me the battery was fine. No problems. I continued getting the "low battery" alerts. I took my G 63 to the dealer again for my 20,000 mile B Service. I told them I still get the "low battery" alerts periodically (not all the time??). They checked the battery and alternator again, and said everything was fine.

I started measuring the starter batter voltage in the morning and at night for a few weeks, and the voltage measurements consistently ranged between 12.2V to 12.3V. This is about 60% to 70% charged for a 12V AGM battery. I put the battery on a battery tender all night, and the volt reading was 12.65V (close to 100 percent). I drove the car like normal around town for a few days, and I measured the battery again. It was back around 12.3V (70 percent). I called an independent Mercedes service shop I use periodically, and I told them all the details about the battery behavior, and the "low battery" alerts. They didn't flinch. They simply said "the battery behavior is normal. As long as you are above 12V (about 50 percent) you are fine.

I'm not particularly happy about this battery behavior being "normal", but the truck starts every day so I don't think there's anything else I can do. Mercedes isn't worried about it, and my independent shop isn't worried about it ¯⁠\⁠_⁠(⁠ツ⁠)⁠_⁠/⁠¯

I did read another post on MBworld talking about turning off Wi-Fi/cellular connectivity to reduce parasitic draw on the battery. I don't use HotSpot in the G 63, so I decided to turn it off. I haven't had a chance to monitor the battery, but I suspect the impact on the battery will be negligible. But, it might help a little.

 

@sweet63 we had the exact same situation with our gls. It was driven just about every day but the distance between home and the clinic that she works at is about 1 mi. We were creating more draw on the battery than the alternator had a chance to recover on the very short trip between Here There and Back to here. For us the solution was a battery tender and or at least once a week drive the car for 45 minutes to an hour or so to get things charged back up

 

Hi. I can understand how driving only a couple of miles a day might result in a low battery. I was driving more like 30 miles a day which seemed relatively normal, more or less. Apparently, 30 miles a day or so is good enough to keep the battery around 70 percent charged which is good enough to start the car every day...but not quite good enough to keep the Mercedes Me app happy. I have a battery tender that I can easily connect anytime to top off the starter battery. I actually did it one night and I checked the battery in the morning and it was 12.6V (basically fully charged). But, after a couple of days it was back to about 12.3V (70 percent). So, in my case, it's not really worth bothering to top the battery off because it seems to settle at around 70 percent which starts the car. The Mercedes dealer and my independent MB shop were both happy with the battery being at 70 percent. I'd prefer closer to 100 percent, but ¯⁠\⁠_⁠(⁠ツ⁠)⁠_⁠/⁠¯