Install: Odyssey PC925 +Battery Relocation

Continuing on with Project +Lightness, today we are going to delete the OEM size battery from the engine bay and replace it with a smaller and lighter battery in the trunk. I chose the Odyssey PC925. It is still a 28 lb battery but it is rated for in cabin use and since this is still my daily, I want to keep those CCAs as high as possible. 20170407-IMG_0295.jpg

For a mounting bracket I chose this one from batterypete on eBay. I went with a vertical mount to preserve as much horizontal space as possible. However, I don’t use my trunk that often so it may not matter either way. Also grabbed some terminals from batterypete as well.

I ordered 12-feet of 2/0 AWG welding cable from eBay as well. In retrospect this is probably overkill and I might replace it with a 1/0 AWG cable or smaller since the 2/0 AWG cable is bulky and heavy. For the ground wire I used some 4 AWG wire I had laying around 2/0 that I ordered from the same vendor on eBay.

First thing you will probably want to do is remove the battery. I didn’t. I went straight to the trunk to figure out where this battery is going. My initial plan was to put it on the passenger side in the rear corner. But I have plans for the corner so I needed another location. 20170407-IMG_0323.jpg

Ideally you want it as close to the center of the car as possible. Due to the fuel tank access panels at the rear seats I decided to stick it either in the rear driver’s side corner or near the strut tower.20170407-IMG_0331.jpg


I chose to be closer to the center of the car. Because racecar. 😀20170407-IMG_0332.jpg

First things first, double check and make sure there aren’t any lines or wires on the other side of where I needed to drill, then mark your locations. 20170407-IMG_0333.jpg

Then drill baby drill!20170407-IMG_0340.jpg

Then clean baby clean!20170407-IMG_0342.jpg

I used a nearby hole in the chassis to mount the ground wire. Make sure to sand down any paint to bare metal for a good connection. I did this later on.20170408-IMG_0343.jpg

Then I finally got around to pulling my off gassing, corrosive, POS battery!20170407-IMG_0321.jpg

Good riddance!20170408-IMG_0349.jpg

At this point I am plotting where I am going to run my wires. The rear seats and front driver’s seat, and any trim along the way, come out for ease of access. A Ryobi 1/2-inch impact is one of my favorite tools and makes this part a cinch.  20170408-IMG_0355.jpg


I also decided to route my power wire through this grommet since the starter is pretty close to this location. 20170408-IMG_0352.jpg

I ended up running my power wire underneath the fuel lines. Fuel lines I didn’t know were there before. Yay! Because of this, I am probably going to put a fuse on this line in case of an accident.

At some point I realized I wasn’t going to finish this in a day since I didn’t have all the connections I needed and I fooled around with that power wire for longer than I would like to admit. And I may of been working on another part of Project +Lightness at the same time since my interior was apart.

So the next day I ran to the auto parts store to pick up a batch of assorted connections. No one really had what I wanted so I just grabbed a bunch of stuff that was close enough. I needed a 8 AWG connector to extend the fuse box power wire to the starter.

I also needed new cable ends for my power wire. Since no one had anything for a 2/0 AWG wire, I grabbed these at the parts store and made them work.20170409-IMG_0364.jpg

I used the same type on the starter side, only I cut off the hook portion and drilled out the bolt opening to fit over the starter stud. 20170409-IMG_0367.jpg

The battery mount wasn’t as tight as I liked, so I shimmed it snug with some cardboard for now. I think I am going to use pass through bolts or studs sooner rather than later. I also need to find some terminal covers that will fit. 20170409-IMG_0368.jpg

I’m also thinking about turning the battery around to face the other way for added protection against the terminals. And I will probably shorten up that power wire too. I just wanted to make sure everything works and I am happy with this location first.20170409-IMG_0378.jpg

I must admit it looks weird to not see a battery in the engine bay, but everything works fine at the moment. I do have plans for the washer tank space but nothing in mind for the battery space. 20170409-IMG_0384.jpg

As for handling I think I need a few days behind the wheel. I drove my wife’s car while mine was down and her car (a 2013 Subaru Impreza Sport) pretty much destroyed my point of reference. Her car’s steering and brakes feel much better than mine even though I remember when I had my STi her car was terribad. It annoys me to no end to know these things.20170409-IMG_0391.jpg

I still need to tidy up a few loose ends, but so far I am happy-ish with the results.


[4/14/17]Rerouted my power wire through the strut tower.20170414-IMG_0423.jpg



[4/18/17]Upgraded my ground wire to 2/0 gauge.20170417-IMG_0448.jpg

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