Travisc77

I've searched the forums, but haven't seen any threads on replacing the battery in an x166. I think it's under the front passenger seat, but I'm not 100%. A few days ago the battery just wouldn't start the truck, tried but couldn't. So I put it on an overnight charge, the next morning boom started right up. Then it sat for a couple of days, same thing. I'm assuming it's the battery, but will have them check. I'm a little surprised I didn't get a warning, but does anybody know if there is an alternator warning (assuming it's not charging the battery)?

I would assume this is maybe a bit more complicated than replacing battery under the hood, but remains a DIY job. Any feedback on this would be helpful.

Thanks
Travis

mstrbenztech

Yes, the battery is located under the R/F seat. It's not that hard to do, you just have to move the seat all the way forward. There is an air vent and panel that have to come off but pretty simple. You will need a 10mm for the terminals and a 13mm with an extension for remove the hold down nuts. If it's original the battery is due for replacement but an amp draw test and an alternator test should be performed to make sure the alternator output is good and the amp draw test to make sure nothing is slowly draining the battery.

Travisc77

Thanks. I'll take it to auto parts store to run those test, not sure if it's original as I bought as CPO 2.5 yrs ago.

mstrbenztech

You can look at the top of the negative terminal and there should be 4 numbers stamped on it. That is the production date (2513 etc). That is the week and year the battery was produced. The parts store can possibly check the alternator but they won't due an amp draw test for you.

Jason B

Same battery the S class takes. Get from Sam's club, 3 year free replacement and it's $169 INSTALLED! Dealer wants $485 installed and much shorter warranty!

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 TypeIN
Volts:12

Travisc77

Thanks Jason B.

That's a good price, I'll prob need to do it myself tonight as I don't have time to drop it off.

Travisc77

An by the way, I looked and on the negative terminal it says 35/12, so looks to be the original battery. I'm confident that's what the issue is.....

Jason B

Cool, it takes some time, they had it done in about one hour. By yourself it's going take you longer if this is your first time.

Travisc77

Jason B

There's not a lot of room and you could spend hours down there.

Travisc77

Jason B

Install is just about the same, that's probably why there isn't a vid for the x166. This is the exact size Mercedes will give you, but it will say Mercedes. This one might actually be a little more powerful if I remember. Also, the 3 year free replacement is what sold me. These care are heavy on electronics and battery use. I say it's worth for Sam's. You don't even need an appointment usually.

jacobsung

MB Roadside will bring and install a new MB battery at a much cheaper than going to a dealer. If you still have MB Roadside Assistant, call and ask.

DC-BENZ

Good point and very true.

Travisc77

DC-BENZ

If I'm not mistake it's available as long as you spend $99 or more during the year at the dealer, assumedly service (aka oil change is the min).

Dog hauler

Good advice except how on earth does the vent come out? There is a panel over the battery and the air vent covers the back part of the panel, preventing removal of the panel. The panel has two clips that are easy to see and release, but how do you get the air vent out? It's in there quite solidly and I see no latches or clips to release it. Any help is appreciated. Thanks.

Travisc77

Dog hauler

Yes, I cut the carpet and was then able to remove the vent and battery cover. And for sure it's then easy to get to the battery. But getting the battery out of the well it's in is no easy matter unless you have very small hands and very big muscles. I have neither and fought with the miserable thing for quite some time before being victorious.

If MB but a strap length-wise around (under) the battery, life would have been a whole lot easier.

Anyway, thanks to all who helped. My dealer wants just under $600 for a battery change. That's crazy when the battery is probably under $200.

Jason B

See my post above. FREE INSTALL, $169 total installed at sams club. Don't waste the time doing yourself and possibly breaking tabs, etc.

Sam's club

Dog hauler

I'm hard pressed to take any vehicle to Sam's Club. Sure, buy groceries and other stuff there. Maybe an oil change. But having them work on my car is another thing. Even if I don't take a vehicle to the relevant dealer (and when I'm out of warranty, I don't), I want to take it to a shop I know has experience with the vehicle and has trained people I can depend on. Sam's Club auto care center just doesn't make that list. Truth-be-told, no chain auto repair shop makes the list. A fellow I know who started as a mechanic at a large chain repair shop and ended up as a district manager tells hair-raising stories about the quality of the people places like that hire and the sloppy work they do. Places of that ilk just don't pay mechanics enough to get and keep quality people, he told me.

It's not MB snobbery, either. In the past, I've owned everything from Toyotas to Dodges and I wouldn't take them there. I'm sure this discussion has been had here and on other forums, ad infinitum. So be it. If you want to take your MB, or any other car for that matter, to Sam's Club, more power to you. I just won't and if it costs me a few extra dollars in the short run, I figure it's worth it.

Jason B

They do not do oil changes. What they do is batteries & tires all day long only. When your battery is dying and you call the Mercedes dealer and they can't schedule you in for a few days and you need it done now, that's what is great. That's what happened to me. I called them, asked if they've done GL's before, and they did. I'm picky with my car and they guy knew and has done many of these. Said it would take about an hour. Took it over and took about 50 min while I waited. They even had a special rubber sleeve to put on the ground connector as they know how German cars have an aux battery and know the terminals are still live. Class act. Remember, this is what they do all day long. $169 vs $600 and waiting 4 days for Mercedes to get it in, forget it. Time is precious.

Remember this is only a battery, not rocket science, but this sucker hard to get to and they have special tools to get the recessed battery out in the GL and didn't need two people. Sam's club is not Midas, etc. These guys are trained properly and have an upper end clientele vs regular retail shops vs some kid they assign at the Mercedes dealer to do your battery, as the main techs don't do smaller items like that. For those that want to do this, call them, talk to the manager and see how they treat you.

I bring my car to the dealer for dealer items, but this is a battery and when people need a new battery and are in a bind, this is a great service to have.

maneesh

my GL would not start today. Just called mercedes to see if they would replace it like the way they did for my 2002 ML320. However, they said that they don't replace it, they would come and jump start it but I have to take it to the dealership to get it replaced. It looks like they lowered their service levels.

Jason B

That's because the install is as royal pain and almost needs two people.

maneesh

Had it replaced at the STEARLSHIP for 500 and comes with a ridiculous 3 year warranty. Insane. I'm sure the service techs might've built a tool or some metal bracket that goes around the battery to get it out of the space that would make it easier. I can't see myself doing this the hard way every time. I'm sure they must've evolved.