Battery Relocation

Last updated: July 27, 2002

Date: Sat, 20 Dec 1997 14:36:14 -0500
From: Scot Kight

It's not that difficult, but make sure you have good thick cable, and a propane torch.

15-16ft 2awg or larger cable
2awg terminals (get them at trak auto or something) 2 bucks for 2
Propane torch
6 Shrink tubes, the largest kind Home Depot has
Tube Electrical Solder PASTE, not regular solder
SEALED BATTERY (Hawker genesis works great)

  1. Remove battery, tray, and everything else like that...
  2. Cut off ground at its frame attatchement point close to the battery (run your hand back, it terminates about 12in down.)
  3. Look at + connector. See how the piece that attatches to the battery actually screws onto the fuse holder. Unscrew that, that is my mountpoint for my cable.
  4. Now look at the cable you have... get ready for the torch. You dont need dark goggles, this isn't welding.
  5. Cut off enough of the (should be THICK) shielding on the cable, then coat the wire with solder, same thing inside the ring terminal. Put the terminal on the end of the cable, and with the torch using the tip which makes the fine point, heat up the terminal. Get it REALLY HOT. Let it sit in the flame for a 20-30 seconds. The cable will begin to get very hot. It's done for now, let it sit 10 minutes and cool, then put the heat shrink on so it covers both the wire and the conector to hide those few stupid wire strands that just wouldn't go in the connector.
  6. Hard part: Find a hole to put the cable through to get in the cabin. I used the rubber grommit around the steering wheel shaft. You may or may not want to also use that.
  7. Run the cable through your hole, then remove your driver's seat, the under-door plastic panel, the kickpanel, the left foot dead pedal, and the cover over the hatch lever. This will give you enough room to get the cable under the carpet, and then string it back in the thing in the middle. just feel on the floor, you will feel a chamber with a kinda feeling (Chamber, rectangular, about 1.5ft long, with circular cutouts on top. Put the cable in the first O, run it through the chamber, and out the last one. Just makes the install look cleaner.
  8. Keep running the cable to the back of the car, and now comes your choice... Get the cable to wherever you want to put the battery... I have mine in the plastic bin. you can put it anywhere really.


Date: Tue, 9 May 2000 13:15:04 -0500
From: "jasonh" (

I relocated the battery to the rear hatch area yesterday. Being concerned about grounding, and having encountered 3K hesitation in the past, I may have gone overboard on the ground wiring but it seems to work. High quality stereo cable was used throughout. Gold plated set screw type terminal ends were used cause I'm not so good at soldering 1/0 gauge wire.

I removed the battery and its coverings and platform. Wow, I can see the radiator! I located the battery (Optima red top) just under the rear stress bar on the passenger side. It is tied down with cable at the moment. I will probably be repositioning it in the near future.

After disconnecting the negative cable from the battery I re-routed the wire and bolted it to the alternator bracket to get good engine to chassis ground up front. For the positive connection I ran 16 feet of 1/0 gauge wire from the fuse block up front to the battery in the rear. For my primary ground I used 4 gauge cable from the negative battery terminal to a bolt on the chassis in the rear. As an extra ground and a preventative measure I ran an 8 gauge wire from the negative post of the battery to the alternator bracket up front. I hope this will link all grounds and eliminate any grounding problems associated with the vehicle.

I ran all cables through the cabin by using the small access hole behind the front wheel fender liner on the driver side. This opening can be seen in the cabin area just to the left of the wiring block behind the dead pedal. The fender liner must be removed to use this access hole. When the dead pedal and interior pieces are removed and the wiring block is loosed from its perch it is easily accessed. This access can provide for just about any size cable or wiring you need to run from the engine bay to the cabin.

This seems to work great. I can feel a difference on cornering and it doesn't bottom out on the left front corner on dips anymore. YMMV

Date: Thu, 19 Nov 1998 11:04:24 PST
From: "Mike Putnam"

If your interested, I've put the details of the install in the technical section of the San Diego RX7 Club's web site.

See the battery information page in the Upgrades section of this web site for info on batteries and safety. --Steve

Date: Tue, 18 Nov 1997 10:27:18 -0500
From: "Robinette, Maj Robbie D."

If you're planning to move your battery you can get high quality, 2 guage, stranded copper wire from Home Depot for $0.58 per foot. They also sell screw clamp cable ends for the wire (I do recommend you solder them after you clamp the ends on). You will need about 15 feet for the job (that includes a couple feet extra just in case). Jeggs sells battery relocation kits for $60 - $100. Total cost of my relocation was $18.


Carlos Iglesias had the following suggestion for cables:

Jeg's High Performance (1 800 Call Jegs) has the following cables/kits for battery relocation:

P/N             Description                           Price
110-2842        Accel 20' 2-gauge cables             $34.99
895-48000       Taylor Battery Kit                   $42.99
                  incl: 16' 2 gauge cable
                  Pre-terminating cable ends
                  Battery tray/ J-hooks


Brad Barber has a picture of his battery installation.


Date: Thu, 04 Dec 1997 14:04:36 -0600
From: David Liberman

You can purchase an NHRA-approved battery box for less than a hundred bucks. Might be a good investment for those moving their batteries into the cockpit.


One word of warning on relocating the battery to the hatch area - you will need a sealed battery since this is considered to be in the passenger compartment. See the Optimas above for one example. --Steve


Date: Thu, 04 Dec 1997 09:19:03 -0500
From: Jay Wallace (

Michael Wilson wrote:
So why not put the battery behind the passenger seat? According to my cross-weight scale measurements with a driver in the drivers seat, the car is left-side heavy so moving the battery to the passenger side would be an improvement. I have not looked hard in the right fender above the muffler, but I intend to use the spare tire well for full-size spare carrying.

There were two reasons not to (put battery in passenger side bin):

1. The only useful storage space in the cabin is the bin behind the passenger - easily accessible to the driver.

2. I don't like the idea of running the high power battery cable next to the computer on the passenger's side. I suppose that the wire could still be run down the driver's side, but am not sure how much extra effort it would be compared to the gain - remember, the Hawker is only 23 lbs, significantly less than the stock battery.

If you want a BS reason we could talk about lowering the polar moment of inertia, but that is just a cop out.


Date: Thu, 21 May 1998 23:27:08 -0500
From: David Liberman (

>The rules state, and I paraphrase, that any battery in the driver's
>compartment must be enclosed in an approved plastic or metal, sealed
>container that is bolted to the chassis (or floor). 'J' bolts must be
>welded closed to be legal.

Summit Racing, 800-230-3030:

May-June '98 Catalog, page 120, there are three different NHRA-approved battery boxes, ranging in price from $42.95 to $89.95. One kit even includes everything you need to move the battery to the trunk: 20' of cable, j-bolts (which must be welded to be legal), straps, washers, etc.


Date: Thu, 21 May 1998 23:49:41 -0500
From: brad barber (

Thanks for the info, however, I've seen those boxes.

The Hawker is only 6.565"long x 6.920"wide x 4.957"high, much smaller than the 27F size the Summit boxes will accept. My battery location is in the bin area behind the driver's seat. I'm trying to see if anyone has solved the problem of meeting NHRA specs using that area.

This is really a pain (although a necessary deal to be legal), trying to get a box that's basically 7x7x5.


Date: Thu, 04 Jun 1998 22:44:36 -0500
From: brad barber (

Here's the deal. I talked to NHRA Division 4 Tech Chief Craig, who sent me to the NHRA National Tech guy. Bottom line, I've high-teched him with a dry cell battery. If I want to run on an NHRA track, legally, I have to enclose my battery in an aluminum battery box, which is bolted through the floorboard with 3/8" (not metric?) bolts, etc. If any 'J' bolts are used they MUST be welded into a closed loop, etc. Plastic battery boxes, such as marine standard boxes, are legal, but must be held to the floor with the welded-loop style hold downs, etc.

There is no NHRA approved battery box which fits the Genesis snugly enough to fit into the bin areas. I'm cutting bait and starting fabrication of a box this weekend which will bolt to the floor in the driver's bin area. I will cut the bottom of the bin out, so when you open the lid, you will see the top of the enclosure for the Battery and the circuit breakers.

I got bounced at tech, don't like it, and am a marked man/car at the Houston Raceway Park, along with three other dry cell equipped RX7s. I'm going to beat the tech guy at his game. I understand the need for standardized rules, but NHRA doesn't comprehend these high tech batteries.

If the box is easy to fabricate, I may make a few for some folks, otherwise I may just make patterns, so folks can build theirs locally. Details as they happen.


Date: Sun, 05 Mar 2000 07:09:08 -0600
From: brad barber (

I looked into building an NHRA legal box a few years ago, but decided not to drag race my car and stopped the project. I did research the rules and will reply from memory (yipes). My plan was to fab a small box from sheet aluminum for the Hawker. It would go in the driver's bin area after cutting out the bottom of the bin. Here is what I remember about the rules...

The battery, if it is the driver's compartment must be enclosed. The enclosure must be SECURELY bolted through the floor of the vehicle with 3/8" bolts (how many isn't addressed, see tech). The enclosure must be sealed, yet vented to the exterior of the driver's compartment. Any hold down 'J" bolts MUST be welded closed to prevent opening during an accident. Straps which encircle the battery seem legal. IF they go under the base plate which is bolted to the car. The battery MUST have an external cut-off switch, easily accessible, at the REAR of the car.

The NHRA rules are vague and leave a LOT to tech at your strip. I used to be a boat designer and realize that the old thermoformed boat battery cases meet all of the requirements IF it bolted to the car. That would not be safe in ana accident. The rules were written for lead/acid batteries and offered NO help for the new gel battery technology, especially in the vent department.

I talked to NHRA's head tech guy on the phone at one point and he wasn't keen to waver on the subject. Honestly, the guy was very negative, especially when he learned I was talking about an import car. I should've told him I was putting it in my Bowtie.


From: Steve Cirian (
Date: July 25, 2002

> I am planning on relocating my battery.  I am getting an Optima and was
> looking for a nice hold down or mount or whatever you call it.  .
> Is the area under the rear bins flat?  i.e.- Some battery mounting kits
> look like they need to be bolted to a flat surface, e.g.-:
> or
> If I cut out the bottom of the passenger bin, is it flat enough underneath?
> Anyone know the SCCA requirements/rules for relocating a battery (e.g.-
> Solo I or IT)?  I have the NHRA info on my site...
> Anyone know of any other mounting kits for Optimas?


Date: July 25, 2002

Did you consider

They make the Reactor, which comes in a fresh hue of baby blue :)

They offer CNC machined aluminum mounts that are very nice to compliment their batteries. mine is mounted to the tunnel, in the bin, so I DO NOT have to take out the ROLL BAR to remove the bins if the battery dies. I had to take the roll bar out 6 or 7 times so far, 3 of the times was due to the large Optima.


From: Blake Qualley (
Date: July 25, 2002

I know my example is not a 3rd gen, is a race car (no interior), and was done a bit crudely, but I have done a tray in the bin area of my 1st gen. I used a couple short pieces of 1.5-inch angle iron (a bit longer than the depth of the battery), a couple longer pieces of 1/2-inch angle iron (longer than the width of the battery), and some short scraps to create a very solid battery tray with integrated hold down. Here are a couple pics:

I just turned the small angle iron upside-down, put them on top of the larger pieces of angle iron and welded them together to form the basic tray. The battery sits on the larger angle iron and is prevented from moving forward or back by the small pieces, which also function as battery hold down points. Short lengths of scrap were turned on end and used to level the tray, which was then welded to the chassis. I think, with a little care, this could be done on a 3rd gen with acceptable results. Just a thought...

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