Looking to see what batteries guys are using on their FD's when they go with the battery re-location to the back rear bin area. The threads on the site are a bit dated and was wondering if anyone has a newer model battery that they went with that fit and also performed.

In addition, has anyone had any issues running gauges and aftermarket car audio off of one of these smaller types of batteries after the re-location is complete? Thinking a few gauges, possible one or two amplifiers, and one smaller 10 or 12" subwoofer with components in the front and coaxial's in the rear?

Any gouge is appreciated.

-Thanks

 

The big thing with battery relocation is you need a sealed battery. Most people go with an AGM type battery like an Optima battery. Traditional lead acid batteries put out gas that you don't want in the cabin.

Do a lot of reading on the relocation, you do want fairly large gauge wiring. I've seen a LOT of relocated batteries with weird starting/charging issues, many times due to the cables being too small, not being run well, poor grounds, etc.

Also, the battery needs to be very well secured. A loose battery is a big hazard.

Also, consider just going with a smaller battery. I'm running a Miata battery in my car under the hood, gives me enough room for my front mount, is easy to get to and service, and I have zero electrical problems.

Dale

 

My FD used to have a bin mounted battery from a previous owner, it was a Pettit kit I think. That tray was just large enough to fit an Optima PC 1200 AGM, that was the most powerful battery I could find at the time. I had no problems with it, and I have since restored the OEM location and box setup and am using the exact same battery right now 5 years later and the battery still is working great.

+1 on Dale's comment about wiring, plan to run a dedicated ground from the battery to the engine in addition to a body ground. Honestly, IMHO unless there is a driving reason like a larger IC or something the better approach is to not make the mod at all and if you must have more space get a smaller battery tray and battery instead and keep everything under the hood like Dale suggests.

 

I use a Miata battery in the rear bin, 2AWG positive wire to the engine bay and 18" 0AWG to chassis for ground. Been running this setup for several years, no issue whatsoever, just make sure you have a good alternator and don't underdrive it.

 

 

Is it possible to relocate without any damage or cutting in the rear bins?
I am contemplating it myself, but since the interior is mint i am very hessitant to do anything that is not reversible.

 

Unless you are running those things with your car off, otherwise it is the alternator's job to provide the juice, not the battery. My setup is working fine and I have Speedhut gauges, but gauges don't draw much additional load, and I don't have a sound system.

You'll have to cut something unfortunately, that's the only way to feed the wires in and securely mount the battery. I think I drilled 5 holes total in mine, 2 for battery mount, 2 for +/- and 1 for accessory wiring such as fuel pump and other switched 12V source.

 

You could mount it in the hatch area, to avoid hacking up the bins. But you'll still need a couple small holes/grommets in the unibody and in the trunk carpet. You could get an aftermarket trunk carpet to punch holes in and keep the OG on the side.

Some batteries are small enough to fit in the bin, but you'll need to make some holes and mounting provisions. Personally, I don't trust the bins to hold a battery in a collision without mounting directly to the unibody.

I just settled with a mini battery in the engine bay to avoid hacking up the interior. I do still think about a hatch mount from time to time.

 

Looks like ill have to get me a spare set of bins then :/

 

Not wanting to hack up the bins, that's what i did (https://www.rx7club.com/showpost.php...3&postcount=44, post 44). Downside is the raises the center of gravity slightly. Not sure how much difference that makes, but i sourced another bin that i will hack up. The only holes in the body required are two for the battery hooks. It was a slight pain to find a good spot where the fuel tank wasn't in the way. I took out the carpet, primarily because i didn't want to drill through it, but also it might not have allowed the battery box to fit under the strut bar. The positive cable can run inside and then route through the existing opening under the driver fender. I did not know there was an opening there and drilled through the firewall I attached the negative to the body near the battery.

If i had to do it over again, i would probably go with a smaller battery in the engine compartment. Much easier and cheaper.

 

My car used to have my relocated battery negative terminal bonded to the chassis. I agree with the comments in favor of running a separate return current wire to the engine bay. If you don't, you will have a higher resistance path from the alternator to the battery. So your battery won't charge as fast (among other issues). The little bonding strap from the UIM to the firewall will get really hot. Also, I think you would get more EMI since the return and supply current would take a different path between the engine bay and battery.

It is probably better to use a smaller battery in the engine bay.

 

You're welcome. Limited cutting. Holes only.

Battery Relocate by Billy Roetman | Photobucket

 

Also: https://www.rx7club.com/3rd-generati...1011961/page2/

 

Very clean - I like it! I have a red top currently in the trunk and it's a really **** job by the previous owner. He also kindly put a crappy walmart amp in one of the bins so it's cut up anyway - I think I'll use a set-up like that. Are the brackets/hardware still available as the post looks to be a from a few years ago?