Battery size help
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Junior Member
Joined: Aug 2016
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E 350 4-matic
Battery size help
Hello, I have a 2011 E350 4-matic and it's time for a new battery. I go to the battery sites, AutoZone, NAPA, etc. and they all say a group 48 (H6) size battery with an option for a 49 (H8). The 48 is 11 inches long while the 49 is 13 15/16 in length. The Mercedes battery in my car is a group size 94R or H7 and it is 12 7/16 inches. When I go to battery sites, I can find a 94R or H7. I am wondering if that would be the best road to follow. Thanks for any info you might have.
Tom
Tom
Senior Member
Joined: Mar 2010
Posts: 293
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From: Hollywood, CA
Tectitgrau S210
If you car's battery is located in the front, I highly highly suggest you go with a group 49 battery because it does fit.
For the first 5 years we've owned our E550 we've had to change the battery every single year. At first the dealer suspected that our car wasnt going into "rest mode" but then suggested that the real reason was that we we'rent driving the car enough. At that time we were using it for less than 5k miles a year. Every time they replaced the battery under the battery warranty they kept giving us a battery that looked way too small for the battery tray, not sure what size it was. Then our W210 wagon's OEM Varta battery finally dies after 11 years!! and when I replaced it I noticed that it was HUGE compared to the W212's battery that the dealer kept giving us. I bough a group 49 battery for the W210 and the next time the W212's battery died (for the 5th time) I swapped over the Grouip 49 battery from the W210 and sure enough it fit. I bough a Group 49 battery for the W212 and its going on 2 years and the battery has not died yet, which is a record for this car.
So if your car is highly optioned like ours is, I strongly suggest you go with the Group 49 battery.
For the first 5 years we've owned our E550 we've had to change the battery every single year. At first the dealer suspected that our car wasnt going into "rest mode" but then suggested that the real reason was that we we'rent driving the car enough. At that time we were using it for less than 5k miles a year. Every time they replaced the battery under the battery warranty they kept giving us a battery that looked way too small for the battery tray, not sure what size it was. Then our W210 wagon's OEM Varta battery finally dies after 11 years!! and when I replaced it I noticed that it was HUGE compared to the W212's battery that the dealer kept giving us. I bough a group 49 battery for the W210 and the next time the W212's battery died (for the 5th time) I swapped over the Grouip 49 battery from the W210 and sure enough it fit. I bough a Group 49 battery for the W212 and its going on 2 years and the battery has not died yet, which is a record for this car.
So if your car is highly optioned like ours is, I strongly suggest you go with the Group 49 battery.
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From: V E G A S
1922 Ford Model T / no OBD
I think the best battery deals are still at PepBoys for Bosch batteries. I have one, about 4 years old and Solar tester shows that from 1000 CA it dropped to about 900, but having 90 months warranty I am not worried.
There are 2 aspects to fitting the battery:
1. MB makes battery clamp on the long end, so when you buy shorter one- the clamp might not fit. Measure the distance you have and confirm it with tape measure before hosting the battery to car.
2. CA and amp-hr. the batteries are rated. Also CCA, what applies to cold weather.
Mercedes does put huge batteries in the cars as lot of things works on electricity and some owner will use seat heaters with engine off, or others will run stereo at full blast for several hr. If you don't do those things and don't start the car in negative of Fahrenheit - you'll be just fine with even 20% lower capacity,
There are 2 aspects to fitting the battery:
1. MB makes battery clamp on the long end, so when you buy shorter one- the clamp might not fit. Measure the distance you have and confirm it with tape measure before hosting the battery to car.
2. CA and amp-hr. the batteries are rated. Also CCA, what applies to cold weather.
Mercedes does put huge batteries in the cars as lot of things works on electricity and some owner will use seat heaters with engine off, or others will run stereo at full blast for several hr. If you don't do those things and don't start the car in negative of Fahrenheit - you'll be just fine with even 20% lower capacity,
Senior Member
Joined: Mar 2010
Posts: 293
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From: Hollywood, CA
Tectitgrau S210
That's the battery I bough, the Bosch Blue-Top AGM Group 49 from PepBoys for 160ish with 30% off discount code "MMJ30".
Up until now I only bought OEM Mercedes batteries, but ever since I noticed that the latest OEM batteries that the dealer sells are no longer made in Spain by Varta I stopped buying them.
Up until now I only bought OEM Mercedes batteries, but ever since I noticed that the latest OEM batteries that the dealer sells are no longer made in Spain by Varta I stopped buying them.
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Joined: Mar 2014
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From: West Central Florida
2011 E550 P2 4M Sedan
Count me as another satisfied customer of Bosch AGM from Pep Boys. 3 years in and going strong.
EDIT - I jinxed myself with this post. The battery ended up dying off a few months later. Oh well, they replaced it under the 4 year warranty.
EDIT - I jinxed myself with this post. The battery ended up dying off a few months later. Oh well, they replaced it under the 4 year warranty.
Last edited by thefisch; Aug 6, 2018 at 06:09 PM.
Thread Starter
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E 350 4-matic
Battery size again
Hello, I appreciate all the good replies, especially Konigstiger providing the original part number. But no one answered my question. The Mercedes original battery is a group # 94R, EN size 77L4, or a DIN size H7. But with the exception on Koninstiger all of the battery replacement sites recommend the smaller H6 or the oversize H8 but never the original size H7. Why is that ?
Thanks again and I'm not trying to beat a dead horse, just want some info.
Thanks again and I'm not trying to beat a dead horse, just want some info.
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MBWorld Fanatic!
Joined: Mar 2014
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From: West Central Florida
2011 E550 P2 4M Sedan
I just checked Autozone for a 2011 E350 and they show H6, H7 and H8 batteries as replacements. Pep Boys only shows the H6 and H8 for your car. When I search for a H7 on Pep Boys with no vehicle selected, I found a hit https://www.pepboys.com/product/details/838845/01810?quantity=1 so you can get it if you want. As to why they don't show the H7 as an option when searching with your car selected, who knows - perhaps their database in incomplete. Doesn't matter - if you want it, get it.
Since the H8 fits and has a larger capacity, I would get that one unless the price difference is worth it on the H6 or H7. At Pep Boys it seems the H6 is $15 cheaper than the H7 or H8, which are the same price in my area. At Autozone, all three sizes are the same price in my area.
Good luck.
Since the H8 fits and has a larger capacity, I would get that one unless the price difference is worth it on the H6 or H7. At Pep Boys it seems the H6 is $15 cheaper than the H7 or H8, which are the same price in my area. At Autozone, all three sizes are the same price in my area.
Good luck.
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Senior Member
Joined: Feb 2009
Posts: 292
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From: Vancouver, Canada
2016 CLS550 4Matic
Related question... when you replace the battery in these cars, do you need to maintain a connection with power to the car to keep from getting any memory loss or codes? And do you need to do anything to code the new battery to the car with a diagnostic scanner?
MBWorld Fanatic!
Joined: Mar 2014
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From: West Central Florida
2011 E550 P2 4M Sedan
No need to maintain power supply or code new battery to car. When I did it on my 2011, all I had to do was set the time again afterwards. All other settings were maintained. I also made sure all glass was completely shut to avoid window resetting.
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Maintaining power while replacing the battery is an Urban Legend. You could potentially screw more things up by trying to attach one power source while removing another. Just pull the battery, neg lead first, then remove pos. Reverse on installation, pos then neg.
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From: V E G A S
1922 Ford Model T / no OBD
It is not urban legend.
On older cars you needed radio code, then steering reset, sunroof reset, all windows reset and garage remote reset. .
Sure W212 remembers, or doesn't need reset. I had mine with battery off for 2 months and it still remember garage codes
On older cars you needed radio code, then steering reset, sunroof reset, all windows reset and garage remote reset. .
Sure W212 remembers, or doesn't need reset. I had mine with battery off for 2 months and it still remember garage codes
Senior Member
Joined: Feb 2009
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From: Vancouver, Canada
2016 CLS550 4Matic
When doing electrical work, I assume you need to disconnect the battery to prevent shorts etc anyway. So changing the battery should be no different.
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From: V E G A S
1922 Ford Model T / no OBD
The aux battery is normally disconnected from the system.
Sure if you have jump cable, you can use it to connect to main clamps, but that brings a risk something will slip and cost lot of damages.
Than again, W212 doesn't need it. I was doing jump cable having 2 of W210 side by side in garage.
Sure if you have jump cable, you can use it to connect to main clamps, but that brings a risk something will slip and cost lot of damages.
Than again, W212 doesn't need it. I was doing jump cable having 2 of W210 side by side in garage.
Senior Member
Joined: Feb 2009
Posts: 292
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From: Vancouver, Canada
2016 CLS550 4Matic
The aux battery is normally disconnected from the system.
Sure if you have jump cable, you can use it to connect to main clamps, but that brings a risk something will slip and cost lot of damages.
Than again, W212 doesn't need it. I was doing jump cable having 2 of W210 side by side in garage.
Sure if you have jump cable, you can use it to connect to main clamps, but that brings a risk something will slip and cost lot of damages.
Than again, W212 doesn't need it. I was doing jump cable having 2 of W210 side by side in garage.
MBWorld Fanatic!
Joined: Mar 2014
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From: West Central Florida
2011 E550 P2 4M Sedan
Not sure about W218, but for W212 the trunk mounted aux batteries are to provide power during eco stop (when stopped the engine is off, no alternator) situations. Prior to the eco start/stop feature being added, the dash mounted battery provided power to the electronic shifter if the car was dead and while the car was running supported the HOLD feature. There may be more but that's all I recall.
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From: V E G A S
1922 Ford Model T / no OBD
W212 had 2 systems with dual batteries.
In earlier models the dash-mounted battery was for gear shifting, in ECO-equipped models the trunk battery is for engine ECO starting.
In earlier models the dash-mounted battery was for gear shifting, in ECO-equipped models the trunk battery is for engine ECO starting.
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CLK320
Note that while Group 49/H8 battery does "fit" in the sense that the hood will close, it is too wide to fit properly in the battery slot, and it will cover the holes where you bolt down the battery to the car with the bracket, so the battery will be loose. It will probably not bounce around due to its weight, but just know that you won't be able to secure the battery and it will not sit 100% flush with the slot. At least this is the case with the 2011 E350 convertible.
Senior Member
Joined: Mar 2010
Posts: 293
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From: Hollywood, CA
Tectitgrau S210
Note that while Group 49/H8 battery does "fit" in the sense that the hood will close, it is too wide to fit properly in the battery slot, and it will cover the holes where you bolt down the battery to the car with the bracket, so the battery will be loose. It will probably not bounce around due to its weight, but just know that you won't be able to secure the battery and it will not sit 100% flush with the slot. At least this is the case with the 2011 E350 convertible.
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CLK320
convertibles and coupe are NOT the same as the W212 sedan and wagons. They are essentially restyled C-Class' with W204 C-Class underpinnings,hence probably why you could not for a group 49 battery within yours. I can confirm that a group 49 battery fits just fine within the firewall battery tray of a W212 sedan, and bolts down just fine.
Super Member
Joined: Apr 2016
Posts: 515
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From: Hudson Valley, NY
2012 E350
A battery does need to be bolted down - wonder why you would purposely get a battery that can't be properly secured
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Joined: Oct 2002
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From: Cincinnati
2010 E350 4Matic
Hello, I appreciate all the good replies, especially Konigstiger providing the original part number. But no one answered my question. The Mercedes original battery is a group # 94R, EN size 77L4, or a DIN size H7. But with the exception on Koninstiger all of the battery replacement sites recommend the smaller H6 or the oversize H8 but never the original size H7. Why is that ?
Thanks again and I'm not trying to beat a dead horse, just want some info.
Thanks again and I'm not trying to beat a dead horse, just want some info.
Last edited by MBNUT1; Jul 27, 2019 at 07:28 PM.
MBWorld Fanatic!
Joined: Oct 2002
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From: Cincinnati
2010 E350 4Matic
Just replaced mine with a 49R Bosch from Pep Boys for $146.24 plus tax and core, No real problem on the install didn't apply any voltage while the battery was out. Only issues were the negative terminal on the Bosch was a lot fatter so it took some messing with to get on the post and the 49R is longer so I notice the battery under the box now. Where before I thought the air box was actually a cover for the battery. Started right up no issues with electrical......yet.
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Joined: May 2021
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From: San Diego CA
2008 Mercedes CLK 350
Use your 2nd car, or friends as if to jump-start the one you are changing the battery in.
I worked on a car changing the fuel injectors. I went to a friendly smog check station. The guy used a small handheld OBD2 meter, he says you will fail. Asked what I had done? Disconnected the battery just like they say in every repair manual.
