2012 ML 350 Bluetec Battery Location
 

Ok, like the title says, where did they hide it on this model. No mention of it in the owners manual.

Thanks

The battery is located below the passenger side front seat. It is best to remove the seat to install a new battery. Be prepared to cut the carpet that is below the seat. Recommend you buy the highest quality battery possible so to not need to repeat this chore often.

wal mart has replacement better,cheaper

Ok, so I moved the passenger side front seat all the way forward, and under the back side of the seat is the heat vent for the rear passenger. Moved the seat all the way rearward and there is a computer module that takes up all the space and has about 6 connectors coming out of it. How in the bloody hell do you access the battery, do you remove the heat vent, the computer module, the entire damn seat, or all of the above.......and if so, how do you remove the seat......unbolt it from the floor or is there an easier way.

The complete seat needs to be removed. You will see perforations where the carpet needs to be cut. I bought a new Interstate battery for my 2012 ML 350 and they installed it for $100 which I was glad to pay.

So has anyone done this themselves? If so, any tips, DIY info etc......

If I remember correctly the seat is bolted to the floor. I am not certain if there is a requirement to maintain a battery connection while your old battery is removed in order to insure that memory codes are kept.

I have posted your question about the battery replacement on the Mercedes Benz Club of America website. Hopefully someone can provide specific details.

https://www.youtube.com/watch?reload=9&v=o7hfpkJrfLo

Perfect depiction of battery removal, do not remove the seat

THANK YOU!!!

Just to add a bit of info for future battery-changers;I found this out on my 2015 ML350:

YOU CAN DISCONNECT THE MAIN BATTERY FOR AT LEAST 8 HOURS AND NOT LOSE ANY OF THE MYRIAD MEMORY SETTINGS.

I unplugged my engine computer to access the spark plugs, and decided it would be wise to disconnect the battery first.
Just reached under the seat and popped off the plastic cover and the negative terminal - just going that far was really easy.
When I hooked it back up 8 hours later I didn't have to reset windows, seats, or anything.
Only thing that reset was the trip computer - no biggie.
I assume the small auxiliary battery kept everything alive?????

Anyway, appears to be no need to provide external standby power when changing the main battery.
Now, what happens when you change the little battery in the rear is anybody's guess.

Cheers,
DG

Battery
 

Adjust the seat forward and up all the way, remove the push pin plastic rivet
and slide the vent to the right and up out of the way, removed that long cover over the battery by lifting and pulling rearward, then remove the battery hold down bracket a 13 mm socket is needed, then disconnect the negative battery cable , then use a 10mm socket on a long extension and remove the positive cable from the battery, then you can lift the battery out
I use a large pair of visegrips and clamp it to the negative post and heave ho, tilt it out , it weighs about 45 lbs you do not need to remove the seat, cutting the carpet is part of replacing battery, its no fun