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Long time viewer, this is my 1st post here. Hope my information can help other people who is going to change the main battery and Aux battery.
For changing the main battery, you don't have to cut the carpet. Just move the negative cable and ventilation tube out of the way completely. The current opening is just big enough for you for pull the main battery out forcefully.
For changing the Aux battery, you only need do the following:
1. remove the back cover plate by remove 1 bolt (T30),
2. loosen one end of the side plate by remove 2 bolts (T30), 2 plastic pins
3. loosen the back end of the side panel by remove 2 attachments (1 T40, 1 T30)
4. no need to pull the rubber seal out, just push it back then you can pry the side panel out.
Now you can fully access of the Aux battery.
Wow, thank you so much, I was planning on replacing the main battery in next couple of weeks, not only this would help me keep the carpet intact, I am considering replace the aux battery now.
Long time viewer, this is my 1st post here. Hope my information can help other people who is going to change the main battery and Aux battery.
For changing the main battery, you don't have to cut the carpet. Just move the negative cable and ventilation tube out of the way completely. The current opening is just big enough for you for pull the main battery out forcefully.
For changing the Aux battery, you only need do the following:
1. remove the back cover plate by remove 1 bolt (T30),
2. loosen one end of the side plate by remove 2 bolts (T30), 2 plastic pins
3. loosen the back end of the side panel by remove 2 attachments (1 T40, 1 T30)
4. no need to pull the rubber seal out, just push it back then you can pry the side panel out.
Now you can fully access of the Aux battery.
For changing the main battery, you don't have to cut the carpet. Just move the negative cable and ventilation tube out of the way completely. The current opening is just big enough for you for pull the main battery out forcefully.
What about the positive cable? There is access to positive terminal only when carpet is pulled.
Very good question.
After removed the battery clamp from the bottom, I was able to pull the battery out a little bit, this gave me more room. To reach the positive side, I have to put an 18 inch (or maybe 24 inch) extension between the 10mm socket and the ratchet. Because of the angle of the bolt on positive side, it was easy to loosen the bolt, after that, I was able to pry the connector off the post easily.
This web site can sell the OE parts in all dealer’s stock room with a discount price! I called my local dealer to make sure they have the batteries in stock, then placed the order through the “mbparts” web site. This web site allows me to choose which dealer I am going to pickup the parts. After placed my order, usually I would get confirmation from my local dealer in 2 hours and I would pick my parts up on my way home.
The main battery is $206 and the Aux battery is $110.
P.S. I am not affiliated with any MB dealer or website.
Wish everyone trying to do this be mindful not to cause any short circuit within that tight space! cover your exposed terminal securely before using ratchet/extension. be careful.
This web site can sell the OE parts in all dealer’s stock room with a discount price! I called my local dealer to make sure they have the batteries in stock, then placed the order through the “mbparts” web site. This web site allows me to choose which dealer I am going to pickup the parts. After placed my order, usually I would get confirmation from my local dealer in 2 hours and I would pick my parts up on my way home.
The main battery is $206 and the Aux battery is $110.
P.S. I am not affiliated with any MB dealer or website.
-Bend your knees and pick up the battery, THEN straighten your legs. Don't lift with eyour back. This beast is VERY heavy!
-You can get the battery out easier if you slip a pry bar down into the hole on the short (closest to you) side of the battery. This way you can slide the battery up the pry bar like a ramp, instead of lifting it out.
-Can unbolt the positive terminal with battery in place, but MAKE SURE you don't ground the extension or socket handle on anything at all. Be very careful!
-All of these steps (except the AUX battery) are exactly the same between every W164 and W166 model (including X164 and X166)
-Wear gloves if you're pulling the battery out, so you don't hack up your hands
-Before starting, move the passenger seat ALL the way front, then ALL the way up. Much easier to work with the battery that way.
-Batteries die basically every 7 years. The last 3 I replaced died around the 7th or early 8th year. If you have a 7yr old battery just replace it now and save the hassle.
-Battery age is stamped on the battery terminal itself (negative terminal I think). The date code is xxyy (xx=week, yy=year). So 2614 is the 26th week of 2014 -- about the first week of July 2014.
-The AUX battery doesn't have to be purchased from MB. It's pretty much a universal battery used in UPS units etc. Here's what I bought: 12 Volts 1.3Ah -Terminal F1 - SLA/AGM Battery - UB1213 (note the term 1213 seems to designate 12v 1.3ah. Look for a part number iwth 1213 in it. Lots of these on Amazon)
-Don't forget to reattach the hold-down plate (2 nuts) and the battery vent hose when reinstalling!
-Don't overtighten the clamps when reinstalling. Decently tight so it doesn't vibrate loose is enough. Maybe 1/8 turn of the wrench once finger tight is enough.. even that may be a bit much. The nuts and bolts are soft and easy to strip. It's not a mechanical part like an alternator bolt or wheel lug.. just needs to be snug enough to not vibrate loose, plus a little bit more.. that's all.
-These are relatively easy batteries to change. After I did my first one, I can now replace the battery in about 5 mins tops.
-Bend your knees and pick up the battery, THEN straighten your legs. Don't lift with eyour back. This beast is VERY heavy!
-You can get the battery out easier if you slip a pry bar down into the hole on the short (closest to you) side of the battery. This way you can slide the battery up the pry bar like a ramp, instead of lifting it out.
-Can unbolt the positive terminal with battery in place, but MAKE SURE you don't ground the extension or socket handle on anything at all. Be very careful!
-All of these steps (except the AUX battery) are exactly the same between every W164 and W166 model (including X164 and X166)
-Wear gloves if you're pulling the battery out, so you don't hack up your hands
-Before starting, move the passenger seat ALL the way front, then ALL the way up. Much easier to work with the battery that way.
-Batteries die basically every 7 years. The last 3 I replaced died around the 7th or early 8th year. If you have a 7yr old battery just replace it now and save the hassle.
-Battery age is stamped on the battery terminal itself (negative terminal I think). The date code is xxyy (xx=week, yy=year). So 2614 is the 26th week of 2014 -- about the first week of July 2014.
-The AUX battery doesn't have to be purchased from MB. It's pretty much a universal battery used in UPS units etc. Here's what I bought: 12 Volts 1.3Ah -Terminal F1 - SLA/AGM Battery - UB1213 (note the term 1213 seems to designate 12v 1.3ah. Look for a part number iwth 1213 in it. Lots of these on Amazon)
-Don't forget to reattach the hold-down plate (2 nuts) and the battery vent hose when reinstalling!
-Don't overtighten the clamps when reinstalling. Decently tight so it doesn't vibrate loose is enough. Maybe 1/8 turn of the wrench once finger tight is enough.. even that may be a bit much. The nuts and bolts are soft and easy to strip. It's not a mechanical part like an alternator bolt or wheel lug.. just needs to be snug enough to not vibrate loose, plus a little bit more.. that's all.
-These are relatively easy batteries to change. After I did my first one, I can now replace the battery in about 5 mins tops.
Thank you for all the tips. Very helpful !
One thing maybe worth to mention, the Aux Battery has 2 versions. Some ML got the 12v 1.3Ah battery and the others got the 12v 14Ah battery. Mine is the 14Ah one.
2015 ML350, late 2014 production
Current 55K miles, bought 2018 with 15K
Have been following and looking at info about changing battery as mine is original, and it seems that 7 years is the max for them to last. Just yesterday some weird stuff was happening, check engine light came on, and car limped the last half mile home. (this just happened to occur after filling up with a cheapy brand of gas - - hard to find gas around here . . . ) Thought I would go ahead and change batteries.
Called dealer for pricing: $257 for main which is list, $200 for auxiliary which didn't make sense considering the comments on this thread. Looked at mbparts.com and it shows THREE batteries: https://mbparts.mbusa.com/v-2015-mer...rical--battery Am I missing something? Thanks
After did the work I would actually recommend cutting the carpet, it’s meant to be cut, although it’s possible to do it without cutting, it will take you much longer to remove the peg holding the vent and cover, and making putting it back a difficult and risky business, you can’t align the holes by visual, if you are not extremely careful and let the thing fall into the gap between battery and compartment, you likely would have to remove the battery again.
2015 ML350, late 2014 production
Current 55K miles, bought 2018 with 15K
Have been following and looking at info about changing battery as mine is original, and it seems that 7 years is the max for them to last. Just yesterday some weird stuff was happening, check engine light came on, and car limped the last half mile home. (this just happened to occur after filling up with a cheapy brand of gas - - hard to find gas around here . . . ) Thought I would go ahead and change batteries.
Called dealer for pricing: $257 for main which is list, $200 for auxiliary which didn't make sense considering the comments on this thread. Looked at mbparts.com and it shows THREE batteries: https://mbparts.mbusa.com/v-2015-mer...rical--battery Am I missing something? Thanks
Thanks for info and links. I did find the two batteries at AutoZone and installed them. Bought their Duralast Platinum brand - $200 & $110. - saved almost $150 over the dealer prices. Check engine light is gone and car is running smooth. Thanks for your help.
Good to know they had the aux battery in stock. I'll have to look for that next time I am in an auto parts store. Mercedes parts (filters, batteries, etc.) seem more available in stock than I thought they would be.
I don't see the point in doing the battery change without cutting the carpet....It's all covered up especially the main battery, and makes the task that much more harder.
04-10-2021, 09:17 PM
