Main battery replacement 2012 GL350... Who's done it?
Thread Starter
MBWorld Fanatic!
Joined: Dec 2001
Posts: 3,430
Likes: 187
From: USA
W140 Mercedes S350, W221 S550 sport
Main battery replacement 2012 GL350... Who's done it?
I think my main battery is gone. Original is 6 years old now. Who's changed their own? I get my batteries from SAMs usually. Do you have to remove pass seat or just move seat up?
and nothing else special needs to be done? Just unhook and replace?
Member
Joined: Mar 2016
Posts: 87
Likes: 6
2010 GL350
I changed out the battery on my 2010 GL without any problem, but with a BIG CAVEAT.
There is a Sears Auto with a drive thru battery lane about 2 miles from my house, which has always been the quickest and cheapest way to change a dying battery. But they refused to change my 2010 GL battery because they had previously screwed up GL & ML battery changes, requiring towing to the dealer and $1000 repair charge. They are no longer allowed to change GL and ML batteries. So apparently there is some risk to DIY if you are not careful.
Here is the youtube video guide that I followed. Not the slickest production, but thorough and includes a list of tools.
I was careful to tape off each lead as I disconnected it so there was no chance of a short.
The only thing I would add is to connect another battery to your your jumper cable posts before you disconnect the dying battery. That seems to preserve some settings in case the aux battery is weak as well.
I expect more experienced members will chime in to correct or clarify these comments, but it worked for me.
And FWIW when it's this much of a hassle to change the battery, I believe in buying a quality battery, not the cheapest available.
There is a Sears Auto with a drive thru battery lane about 2 miles from my house, which has always been the quickest and cheapest way to change a dying battery. But they refused to change my 2010 GL battery because they had previously screwed up GL & ML battery changes, requiring towing to the dealer and $1000 repair charge. They are no longer allowed to change GL and ML batteries. So apparently there is some risk to DIY if you are not careful.
Here is the youtube video guide that I followed. Not the slickest production, but thorough and includes a list of tools.
The only thing I would add is to connect another battery to your your jumper cable posts before you disconnect the dying battery. That seems to preserve some settings in case the aux battery is weak as well.
I expect more experienced members will chime in to correct or clarify these comments, but it worked for me.
And FWIW when it's this much of a hassle to change the battery, I believe in buying a quality battery, not the cheapest available.
Last edited by Callisto1; Jan 7, 2018 at 04:43 PM.
Senior Member
Joined: Mar 2009
Posts: 401
Likes: 31
From: CT
GL 450, 993TT, Cayenne Diesel, 964C4
I had my tender plugged in so no memory would be lost. Be careful of your ratchet handle is all metal. I would tape up the handle end so you dont accidentally hit a negative terminal when unbolting the positive.
Yes move your pass seat up and forward as much as you can. Plenty of good instructions on youtube and replace the aux battery at the same time. OEM backup battery was like $40. Duracell from batteries plus replacement was $15-20.
Yes move your pass seat up and forward as much as you can. Plenty of good instructions on youtube and replace the aux battery at the same time. OEM backup battery was like $40. Duracell from batteries plus replacement was $15-20.
MBWorld Fanatic!
Joined: May 2015
Posts: 1,932
Likes: 291
From: Allentown, PA
'08 GL 320 CDI
I was at my indy dealer when he replaced my battery. I was going to take it home to do it, but he did it for free. He removed the seat rather than struggling with sliding it in under the seat. It took all of about 3-5 minutes to remove the seat. I was surprised it was so easy to remove the seat - certainly seems like time well spent when it makes the actual job much easier and safer (much less chance of shorting something).
Thread Starter
MBWorld Fanatic!
Joined: Dec 2001
Posts: 3,430
Likes: 187
From: USA
W140 Mercedes S350, W221 S550 sport
Thanks guys, I was able to trickle charge it overnight and it seems to be doing very well the past two days… One question I have is the vent cover under the seat won't snap down flush anymore and I'm not sure why, any tips? The cover black cover right below the vent cover that snaps in with the tabs doesn't seem to push down fully flush and can't get it to.
MBWorld Fanatic!
Joined: May 2015
Posts: 1,932
Likes: 291
From: Allentown, PA
'08 GL 320 CDI
So either something is obstructing it from the underside/around the edge, or the latching mechanism is worn/broken. You'll have to look closer to figure it out. I'd help, but it's hard to do that from here in PA! 
Thread Starter
MBWorld Fanatic!
Joined: Dec 2001
Posts: 3,430
Likes: 187
From: USA
W140 Mercedes S350, W221 S550 sport
Trending Topics
MBWorld Fanatic!
Joined: May 2015
Posts: 1,932
Likes: 291
From: Allentown, PA
'08 GL 320 CDI
Small world!
FYI, just keep on top of the battery issue. If the car is used on a regular (even a somewhat regular) basis, it shouldn't need to be charged. A healthy battery should start your engine even after sitting for 2 weeks. I've had no issues starting my engine (which takes more juice to start it since it's a diesel) after sitting for even longer than that. If you continue to have a problem, there's either an excessive draw on it somewhere or the battery is, indeed, on it's last legs. For good measure, what's the voltage reading at the battery when the engine is running? 14-ish is about right.
FYI, just keep on top of the battery issue. If the car is used on a regular (even a somewhat regular) basis, it shouldn't need to be charged. A healthy battery should start your engine even after sitting for 2 weeks. I've had no issues starting my engine (which takes more juice to start it since it's a diesel) after sitting for even longer than that. If you continue to have a problem, there's either an excessive draw on it somewhere or the battery is, indeed, on it's last legs. For good measure, what's the voltage reading at the battery when the engine is running? 14-ish is about right.
MB World Stories
The Best of Mercedes & AMG
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
10 Most Reliable Mercedes-Benz Models You Can Buy Used
Verdad Gallardo
Member
Joined: Mar 2016
Posts: 87
Likes: 6
2010 GL350
If the battery is 6 years old, just replace it now and save yourself the headache of when it dies without warning at the most inconvenient time. My GL battery died in Everglades Nat'l Park with no cell service when the battery was 3 years old. Got the park ranger to help and we jump started it from his golf cart batteries. At 3 years old, my 1998 E320 wagon battery died as I was leaving my office to take an important client to lunch. No prior warning no nothing, but the battery was so dead it wouldn't even open the door locks. Dealer sent a service vehicle with new battery and the service tech said that was par for the course. 3 to 4 years. So 6 years is extended life support. I replaced my E320 battery every 4 years after that, and in 2013 sold the car to my oldest friend who is still driving it in Maine today with no other problems besides replacing the cheap plastic gears in the power windows. And cloudy headlight covers of course. Wish I could say the same about reliability on the GL350...
Junior Member
Joined: Aug 2016
Posts: 25
Likes: 1
2013 S550, 2012 GL550
HI Jason,
How do you like your GL? I just picked up a 2012 GL550 for my wife. Will you be adding some MidCity Engineering toys to this car as you did to your S550? I am thinking about adding the remote starter to this one as well. I love it on the S550 I have, especially in the summer.
Cheers,
Ivan
How do you like your GL? I just picked up a 2012 GL550 for my wife. Will you be adding some MidCity Engineering toys to this car as you did to your S550? I am thinking about adding the remote starter to this one as well. I love it on the S550 I have, especially in the summer.
Cheers,
Ivan
Thread Starter
MBWorld Fanatic!
Joined: Dec 2001
Posts: 3,430
Likes: 187
From: USA
W140 Mercedes S350, W221 S550 sport
Small world!
FYI, just keep on top of the battery issue. If the car is used on a regular (even a somewhat regular) basis, it shouldn't need to be charged. A healthy battery should start your engine even after sitting for 2 weeks. I've had no issues starting my engine (which takes more juice to start it since it's a diesel) after sitting for even longer than that. If you continue to have a problem, there's either an excessive draw on it somewhere or the battery is, indeed, on it's last legs. For good measure, what's the voltage reading at the battery when the engine is running? 14-ish is about right.
FYI, just keep on top of the battery issue. If the car is used on a regular (even a somewhat regular) basis, it shouldn't need to be charged. A healthy battery should start your engine even after sitting for 2 weeks. I've had no issues starting my engine (which takes more juice to start it since it's a diesel) after sitting for even longer than that. If you continue to have a problem, there's either an excessive draw on it somewhere or the battery is, indeed, on it's last legs. For good measure, what's the voltage reading at the battery when the engine is running? 14-ish is about right.
HI Jason,
How do you like your GL? I just picked up a 2012 GL550 for my wife. Will you be adding some MidCity Engineering toys to this car as you did to your S550? I am thinking about adding the remote starter to this one as well. I love it on the S550 I have, especially in the summer.
How do you like your GL? I just picked up a 2012 GL550 for my wife. Will you be adding some MidCity Engineering toys to this car as you did to your S550? I am thinking about adding the remote starter to this one as well. I love it on the S550 I have, especially in the summer.
Funny, I'm a dealer for MidCIty which makes a remote start that works with the factory Mercedes key. Very cool, works for all Mercedes makes and models and is a must since you don't need a NEW KEY. I need to add pics in here for your guys to see this thing. I was out the other day and a guy came up to me and said, "hey, what year is that? 2020?" ha,. It looks great with this wrap.
Junior Member
Joined: Aug 2016
Posts: 25
Likes: 1
2013 S550, 2012 GL550
Very nice, Jason! The wheels are awesome. I need to get my wheels redone on the GL, got the car with some curb rash. The car has chromed 21" AMG rims and the chrome is peeling in couple of spots. I am not big fan of chrome wheels, but wife likes it. Well, it is her car so I will probably stay with the chromed look for now, just have it refinished in PVD chrome, rather than re-plating the old way.
Cheers,
Ivan
Cheers,
Ivan
Thread Starter
MBWorld Fanatic!
Joined: Dec 2001
Posts: 3,430
Likes: 187
From: USA
W140 Mercedes S350, W221 S550 sport
Very nice, Jason! The wheels are awesome. I need to get my wheels redone on the GL, got the car with some curb rash. The car has chromed 21" AMG rims and the chrome is peeling in couple of spots. I am not big fan of chrome wheels, but wife likes it. Well, it is her car so I will probably stay with the chromed look for now, just have it refinished in PVD chrome, rather than re-plating the old way.
Last edited by Jason B; Jan 10, 2018 at 01:45 PM.
Thread Starter
MBWorld Fanatic!
Joined: Dec 2001
Posts: 3,430
Likes: 187
From: USA
W140 Mercedes S350, W221 S550 sport
Ok, well, battery died again. So, it seems this is the same battery that the w221 S class takes. I got one in that a year ago from Sam's. 3 year free replacement and it's $169 installed. Dealer wants $485 isntalled
Going to do it later this week and have them do it.
http://www.samsclub.com/sams/auto-gr...uestid=4375412
$169
Specifications
20 amp hour rate:92
Battery Electrolyte Composition:Glass Mat
Battery End Type:Top Post
Battery Purpose:Starting Lighting Instrumentation
BCI Group Size:49
CA at 32 degrees F:975
CCA at 0 degrees F:850
DIN code:H8/L5
Freight Class:65
Polarity:Right Positive
Reserve Capacity:170
Terminal Type
IN
Volts:12
Going to do it later this week and have them do it.
http://www.samsclub.com/sams/auto-gr...uestid=4375412
$169
Specifications
20 amp hour rate:92
Battery Electrolyte Composition:Glass Mat
Battery End Type:Top Post
Battery Purpose:Starting Lighting Instrumentation
BCI Group Size:49
CA at 32 degrees F:975
CCA at 0 degrees F:850
DIN code:H8/L5
Freight Class:65
Polarity:Right Positive
Reserve Capacity:170
Terminal Type
INVolts:12
Thread Starter
MBWorld Fanatic!
Joined: Dec 2001
Posts: 3,430
Likes: 187
From: USA
W140 Mercedes S350, W221 S550 sport
Junior Member
Joined: Mar 2007
Posts: 43
Likes: 1
From: Reno
2010 GL450 and 2016 GLE350
Removing front seat.......
I was at my indy dealer when he replaced my battery. I was going to take it home to do it, but he did it for free. He removed the seat rather than struggling with sliding it in under the seat. It took all of about 3-5 minutes to remove the seat. I was surprised it was so easy to remove the seat - certainly seems like time well spent when it makes the actual job much easier and safer (much less chance of shorting something).
Did not bother with keeping the circuit alive. Though both batteries were out for 3 hours, it took all of five minutes sitting in the driver's seat to reset the 6 windows and sun roof auto open and close features. The only memory lost was the radio presets (big deal) and probably the transmission education, another no big deal..........It's far preferred to taking a chance with sparks and shorts and possible damage to the computers......
Thread Starter
MBWorld Fanatic!
Joined: Dec 2001
Posts: 3,430
Likes: 187
From: USA
W140 Mercedes S350, W221 S550 sport
Yesterday, changed the battery in my 2010 GL. Scoffed at your description of removing the seat......Wished I had heeded your advice. It took the two of us 4 hours, scuffed fingers, and sore muscles from standing on our heads to get the battery out, but then replacing the aux battery which I remembered as an easy switch on the ML, was an ordeal on the GL. Removing the seat would have saved 3 hours and a lot of aches and pains.
Did not bother with keeping the circuit alive. Though both batteries were out for 3 hours, it took all of five minutes sitting in the driver's seat to reset the 6 windows and sun roof auto open and close features. The only memory lost was the radio presets (big deal) and probably the transmission education, another no big deal..........It's far preferred to taking a chance with sparks and shorts and possible damage to the computers......
Did not bother with keeping the circuit alive. Though both batteries were out for 3 hours, it took all of five minutes sitting in the driver's seat to reset the 6 windows and sun roof auto open and close features. The only memory lost was the radio presets (big deal) and probably the transmission education, another no big deal..........It's far preferred to taking a chance with sparks and shorts and possible damage to the computers......
And on the secondary battery for the GL, you're saying that's not easy to do? I've seen it in the rear panel I think before when I tool panel off before.
EDIT, ok didn't realize the aux battery was diff for you 2010. Here is where all batteries are for 2012:
Last edited by Jason B; Jan 22, 2018 at 03:49 PM.
Junior Member
Joined: Mar 2007
Posts: 43
Likes: 1
From: Reno
2010 GL450 and 2016 GLE350
The 2010 Gl's aux battery sits beside the main battery. I expect it's the same for MLs and GLs through 2011..........Don't know socket size for seat, 10 or 13mm are favorites with Mercedes.........
Last edited by Keyser Soze; Jan 23, 2018 at 04:02 PM.
MBWorld Fanatic!
Joined: May 2015
Posts: 1,932
Likes: 291
From: Allentown, PA
'08 GL 320 CDI
Replaced battery in 2007 Ml a few years ago. Other than wrestling the old battery up the tight opening, didn't seem to difficult. Yesterday, changed the battery in my 2010 GL. Scoffed at your description of removing the seat......Wished I had heeded your advice. It took the two of us 4 hours, scuffed fingers, and sore muscles from standing on our heads to get the battery out, but then replacing the aux battery which I remembered as an easy switch on the ML, was an ordeal on the GL. Removing the seat would have saved 3 hours and a lot of aches and pains.
Did not bother with keeping the circuit alive. Though both batteries were out for 3 hours, it took all of five minutes sitting in the driver's seat to reset the 6 windows and sun roof auto open and close features. The only memory lost was the radio presets (big deal) and probably the transmission education, another no big deal..........It's far preferred to taking a chance with sparks and shorts and possible damage to the computers......
Did not bother with keeping the circuit alive. Though both batteries were out for 3 hours, it took all of five minutes sitting in the driver's seat to reset the 6 windows and sun roof auto open and close features. The only memory lost was the radio presets (big deal) and probably the transmission education, another no big deal..........It's far preferred to taking a chance with sparks and shorts and possible damage to the computers......
Should be easy enough to figure out what socket/wrench to use by putting a wrench on the bolts? On the other hand, if I had to figure out what size tool to use for the place that is doing the work for me... I think I would find a new place!
But, I think the bolt heads are those external torx head? I'm not positive - take a look under the seat to check. If I'm remembering correctly, though, I think I've used a 6-point wrench on male torx in the past? Probably doesn't fit perfect, but as long as the bolt is rusted up...The battery does not lie on it's side - at least not in my model year... or are you referring to the aux battery? Haven't replaced that one yet and don't recall well enough from when my Indy did the main battery. From the picture/graphic you posted, it looks like the battery is standing normally as well.
Last edited by DennisG01; Jan 22, 2018 at 09:01 PM.
Thread Starter
MBWorld Fanatic!
Joined: Dec 2001
Posts: 3,430
Likes: 187
From: USA
W140 Mercedes S350, W221 S550 sport
I'm happy to report that Sam's did the install today and took them about 50 min, no seat removal. They knew what they were doing, and I showed thema YouTube video just to be safe that they appreciated. The battery cover now fits flush and perfect. The battery I linked above, group 49 is same size as factory battery and AGM, might actually have more cranking amps than factory I think.
$169 installed can't be beat! Truck starts up super fast now!
Last edited by Jason B; Jan 28, 2018 at 03:49 PM.
Junior Member
Joined: Aug 2023
Posts: 18
Likes: 3
From: New Jersey, USA
2011 GL350
Thank you everyone for the information above. Changed my battery the other day using the suggestions above. However, I noticed one of my positive wires was a little browned out. Anyone swap out battery cables before? Is it doable as a weekend wrencher? Parts are easy to find on FCP, but I cannot find a guide on how to do it.
Senior Member
Joined: Aug 2018
Posts: 409
Likes: 121
From: Kelowna, BC
08 GL320 CDI
“Browned out”?? Do you mean corrosion on the cable? If so, I’m sure you can just clean the cable, that corrosion is most likely just on the outside of the copper and be cleaned easily.
