I have a 2002 M3 with a dead battery and cannot locate it. The manual is no help. Is it in the trunk?

Did you look there? (under the mats?)

Check under the rear seat. You should be able to pull up hard on the front of the rear seat on both sides and the seat will pop out. Thats where it is on my 95 525i.

My guess - in the trunk, under the mat on the right side. That's where it is on the e36 and e39.

LOL...please let us know when you find it...I also am wondering about this on my E46...

It's in the trunk, pull out the black plastic cover on the right side behind the tail lights. Good Luck!

thanks!

It's in the trunk on the right side under the plastic cover. When you get a new battery, make sure you go to Autozone and order a 49DL. Its $70, instead of the one that they list which is $120. It also has more cranking capacity, but still fits in the same place. Do a search here for a DIY. I did mine this summer and the car starts great at -5ºF.

yes the battery is in the trunk to the right side- remove the plastic package tray- it can be tricky-u will need a 13mm to remove the hold down bracket and a 10mm for the terminals. I would use a BMW battery- most electrical or computer related issues that we find can be traced back to inferior batteries- there is much more to consider than just CCA's-

FWIW, I'm using a battery from AutoZone in my 530 and I have no problems. I was planning to get a Douglas battery, which is supposed to be OEM, from Batteries Plus, but they stopped stocking them.

BMW stopped using Deta Douglas batteries a while ago. They now use Exide. Douglas got out of the automotive battery market.

Well that explains the shortage of Douglass batteries. :)

It's in the trunk on the right side under the plastic cover. When you get a new battery, make sure you go to Autozone and order a 49DL. Its $70, instead of the one that they list which is $120. It also has more cranking capacity, but still fits in the same place. Do a search here for a DIY. I did mine this summer and the car starts great at -5ºF.

the DL has the terminals reversed; i think you want the 49d.

also, the 49d i bought doesnt drop right into the battery cradle. it was too large. this is the duralast 49d at autozone.

Going oem.

just my .02

I think the battery hold down is adjustable. As far as the terminals being reversed, you could rotate the battery 180 degrees. Also, FWIW, Autozone lists the 48DL for the 1998 e36 323is. Your car might use a different battery.

Make sure whatever battery you go with has a vent tube (since the battery is located in the trunk) unless you go optima (which is what I have and highly recommend) or another completely sealed battery.

rmn,

Does the Optima fit in the battery compartment and the hold down? I was told they did not make a battery that would fit an e36.

Steve

They only make a couple of different batteries (not allot of sizes) so you will have
to modify a bracket I used a piece of aluminium and the original mounting bolt

http://us.a2.yahoofs.com/users/RfGwZ10rvHZc/__sr_/5345.jpg?tkn=phwBk.FBtGXoBjUD&saveas=optima

rmn,

Which Optima battery did you get? I assume it fit entirely in the compartment. I mean it went into the well and the plastic tray went over it.

Steve

Yes, if anyone has a confirmed compatible battery that can be found aftermarket...*please* post up a part number if you can.

I will probably replace my battery before the next winter, and I really don't want to go to a dealer for a freaking battery.

Thanks!

rmn,

Which Optima battery did you get? I assume it fit entirely in the compartment. I mean it went into the well and the plastic tray went over it.

Steve

I got the Redtop 12853 from Costco for around $130.00 (they sell for $160.00 everywhere else) it fit in the battery compartment perfectly with the exception of it being smaller as you can see from the picture in my original post the height was no problem the plastic cover went into place perfectly. These batteries rock it has 720CCA versus the original, which was much larger and heavier with 650CCA


Yes, if anyone has a confirmed compatible battery that can be found aftermarket...*please* post up a part number if you can.

I will probably replace my battery before the next winter, and I really don't want to go to a dealer for a freaking battery.

Thanks!

There are several batteries available all much cheaper then the dealer (my dealer wanted $239.00) I went with the Optima because there design is superior to a conventional battery so it can be smaller/lighter and put out more CCA plus it is a completely sealed battery (you could mount it upside down) allot of conventional batteries say they are maintenance free and say they are sealed they aren’t either. There are cheaper batteries that will fit properly and work as well as the ones from the dealer but, like I mentioned in my original post make sure they have a vent tube that vents the gases from the battery out of the trunk (2 reasons: 1 there is a small chance the gasses could explode and 2 the gases can corrode surrounding materials (I have seen this on my friends M3 all the carpet in the trunk started look like it had a light coating of mold but it was actually from the battery (everyone has seen this on battery post before))). Here is Optima’s web site if you want to read about their technology.
http://www.optimabatteries.com/publish/optima/americas0/en/config/product_info/automotive.html

Unfortunately....Optima's website says they do not offer a battery for my 2003 325I :(

I guess I will have to go with whatever is at the local autozone....vent tube or sealed..doesn't really make a difference to me.

Unfortunately....Optima's website says they do not offer a battery for my 2003 325I :(

I guess I will have to go with whatever is at the local autozone....vent tube or sealed..doesn't really make a difference to me.

It will fit you will have to modify the mounting bracket like I did on my E36 which if you check there site also says no matches available. If you do a search on this site you will find several guys with E46's using the Optima. They only list a car on there WEB site if you can put it directly in with no modifications which if you do a search on there WEB site you will find very few cars since there battery is much smaller then what comes with most cars.

Sure...I think the first step is for me to measure the OEM battery exactly...and then check the Optima specs and see what matches closely.

Modding the bracket is child's play...if that is all I have to do, this is a no brainer. I can easily fab a bracket out of aluminum and paint it.

My original battery measured 7" tall X 7" wide X 12.25 long my guess is yours is the same battery
Here is a picture of my bracket

http://us.f13.yahoofs.com/bc/4442d77fmd83ae419/bc/photos/optima.jpg?BCw5D_FBpJHaxZZo

After you click that link...rename the file with the .jpg extension and you can view it.

For some reason...that link saves the file with no file extension.

Thanks....I will keep that in mind...when I do the optima, I will probably fab the bracket from poster board, then transfer that to aluminum sheet.

After you click that link...rename the file with the .jpg extension and you can view it.

For some reason...that link saves the file with no file extension.

Strange the image showed up when I first posted it now when I edit it and put it back same as the original it comes back. Maybe there was something wrong with the site you should be able to see it now. I originally used a cardboard templete as well.