First a little background...
I needed room in my engine compartment to rout my intercooler piping, and a battery relocation was basically a must. For various reasons I did not want to mount the battery in the trunk, so i decided to mount a Odyssey PC680 (pictured below) battery in front of the drivers wheel wheel well where the windshield washer bottle would normally reside. My ACR did not have a washer bottle when I got it (I was told later on that it did not because it had been used to mock-up a custom battery bracket in the same location), so that location seemed natural. I don't have a welder or the means to otherwise fabricate such a bracket on my own, so I decided to use the Odyssey battery and adapt the corresponding aluminum mounting bracket available separately from Odyssey to fit, despite being told it could not be done.
Here is the Odyssey PC680 compact battery:

Here is the aluminum Odyssey bracket made for the PC680:

I purchased my Odyssey PC680 direct from Odyssey on eBay, and I purchased the Odyssey bracket from Summit Racing. Both of these places seemed to have the best deals, respectively.
BASIC TOOLS NEEDED:
- T-25 Torx [bumper cover]
- 10mm wrench [bumper cover]
- 13mm end wrench [bumper bolts]
- Hack saw
- Propane torch
- Bench vise
- Drill
- 9/32" drill bit
- 3/4" hole saw
MOUNTING HARDWARE:
- 6x 1/4"-20 1" bolts
- 5x 1/4"-20 speed nuts
- 1x 1/4"-20 lock nut
- 7x 1/4" flat washers
- 6x 1/4" lock washers
And before we go any further, here is we will be mounting the battery:[/b]

I will be referring to the "right" and "left" side mounting tabs on the bracket itself. This right and left is in relation to when you are looking at the front of the bracket or mounting location. The left side mounting tab will go toward the front of the vehicle, and the right toward the rear.
First there will need to be three modifications done to the bracket itself:
- Approx. 1/4" of the left mounting tab will need to be trimmed, This is to position the battery and tray further forward to allow adequite space for mouting the rear of the bracket.
- The same left mounting tab will need to have a triangular section removed between the top and middle bolt holes to allow clearance for the trigulated support stamped into the frame rail where it meets the core support (as shown in the images below)
- The right mounting tab will need to be bent back about 10-15 degrees to compensate for a bent in the frame rail..
In this pic you can see where I cut about 1/4" off the very edge of the left side (front of vehicle) mountning tab. This is to tuck the bracket in closer to the area of the front core support that extends past the frame rail.

You will also need to remove the triangle-shaped section of material on that left mounting tab. The best advice I can give you is to map out your mounting holes for the bracket, and then cut the triangular notch out accordingly.
You will notice the sheet metal where we are mounting this tray is not flat, as pointed out in this image:

To compensate for that bend in the unibody structure, we need to do two things: a. Bend the Odyssey bracket's right mounting tab (toward rear of vehicle) back about 10-15 degrees; b. Fabricate a 1/8"thick spacer to mount behind the angled mouting tab. This will mount the battery straight with the front part of the structure we are mounting to, eliminating the possibility of putting undue stress on battery case or bracket by letting it rest on that ridge.
To bend the right mounting tab (toward rear of vehicle), I first locked the tab into a large vice with the back/inside of the bracket facing toward me, using pieces of 1" aluminum angle to cushion the mounting tab from being marred by the steel vice jaws. From there I simply applied lots of heat from a propane torch evenly across the 45-degree bend and slowly, gently pulled the bracket back toward me, while of course wearing gloves to protect my hands from the heat. A propane torch worked for me with a little time and effort, but you may be able to make easier work of this step my using a MAP or other slightly hotter torch.
Here is the spacer I made:

Now onto the car itself...
There will need to be six 9/32: bolt holes drilled, as well as three 3/4 holes cut for the speed nut mounting.


To bend the
Here are the speed nuts you will use to mount the bracket:

Three of these speed nuts will need to be ground down to clear the core support:

Here is the mounting location prepared for the bracket, with the speed nuts in place:

Additional stuff:
- Obviously you cannot retain your windsheild washer bottle.
- I am under the impression that certain model years may have an airbag module near this location. My car did not have one when I purchased it, so I am unsure of any interference.
- Your horn will need to be relocated slightly. The horn is normally attached with the nuts used to hold on the right side of the front steel bumper support. You will want to mount the horn directly below its former home, one hole is provided for you but you will have to drill the second. Attach with appropriate hardware, preferably using lock nuts (especially if you have aftermarket engine mounts!). The wire doing to the horn will not need to be extended.
There is also a similar bracket for mounting the Odyssey PC680 made by Portable Power. I have not seen one in person, but I can't see why it wouldn't work. You would, however, have to mess up the nice powder coat performing the modifications diagrammed above.
Portable Power bracket for Odyssey PC680:
