With lots of searching and question asking, I attempted to find the best products and installation techniques. This is one of many ways that a battery relocation can be done. By no means is this the only, the cheapest, nor the best way. This is the way that made the most sense to me. For many this may be considered extreme.

In this install, I opted for a professional installed finish product. I bought one kit, checked out other kits, and did research (online, books, talking with professionals), only to find that most kits and tutorials were about a minimal install, using cheap and under-rated parts. Nearly all of the info about battery relocation had the positive cable installed underneath car. Although, that would be the easier way, I chose for the protection of running the main cables through the cab of the car.

Most kits contained 2 gauge multi-strand copper cables (one kit even had aluminum cable). An overheated cable, due to improper sizing, can result in the cable burning off its insulation, shorting out, then causing the car to stop, a fire, and/or a battery explosion. Using the Wire Loss Chart, and with the overall length of (about) 20 feet of cable, I chose a larger cable for the main Positive and Negative runs (00 or 2/0 - called 2 ought or double ought) for the least resistance, causing the least current drop. This adds a small amount of weight, but I thought the safety factor to be worth it. Did some searching for a better grade of cable & ends. I found tinned cable and ends (lugs) at a Marine supply. Each strand of the insulated multi-strand copper cables is tinned then sealed in a thicker insulation than the non-marine grade cable. Each solder style lug was pre-tinned. All connections in this project were soldered instead of clamped or crimped. Ever seen green salty-looking battery cables? Effort was made to avoid; corrosion, electrolysis, chaffing, and any other negative affects in this project. All cables were clamped with rubber cushioned - stainless steel clamps.

I chose a sealed gel battery, which has several advantages. One disadvantage is it needs to be trickle charged. I chose the Optima Group 34/78 Redtop, which has 800 Cold Cranking Amps. Click here for more information. The OEM Ford battery was a 540 Cold Cranking Amp battery. I over-killed with the extra Cold Cranking Amps due to the cable length of (about) 20 feet, plus extra cranking power will help for cold day starts, and higher compression starts. NOTE: In all of my over-killing, I had hopes to see the motor start in less cranks than original (since it was common to start in 3 revolutions). There was no change after all was installed.

In this application, I added a battery cut-off switch, which is necessary by NHRA rules if you relocate the battery, and race on NHRA race tracks: "Any car with a relocated battery must be equipped with a master electrical cutoff, capable of stopping all electrical functions including ignition (must shut the engine off, as well as fuel pumps, etc.)". Click here to read the NHRA Tech FAQ.

There are several Battery Disconnect (Kill) Switches available, but many are underrated and some (like the key style) do not qualify for the NHRA rules. I chose the Moroso Super Battery Disconnect Switch, both for the rating of 2,000 amps intermittent and 300 amps continuous, and for the optional Push/Pull Battery Disconnect Mounting Kit (external push switch is necessary for NHRA rules). More information is available here. I made an aluminum box to encase the Disconnect switch and cover the connections. To have the disconnect switch actually kill the motor, It was necessary to bypass the alternator cable, sending it to the battery side of the kill switch, otherwise the alternator would keep the car running after the kill switch was flipped. I used double the stock size cable for this alternator bypass, a 4 gauge tinned multi-strand copper cable.

Some tutorials I read, the installer added fuses to each positive line from the battery, but decided not to do this in my install since I've never seen a fuse on the main battery cables in a stock vehicle, and since I've made sure the cables, the connectors, and the battery will have little chance of shorting out.

There are several battery boxes available that qualify for the NHRA rules. NHRA states: "the battery must be completely sealed from the driver and/or driver compartment. This means a metal bulkhead must separate the trunk from the driver compartment, or the battery must be located in a sealed, metal box constructed of minimum .024 inch steel or .032 inch aluminum, or in an NHRA accepted plastic box." My convertible is open behind the back seat so I opted for a battery box. I chose the Taylor Aluminum Battery Box for the clean look and the 3 piece design. The 3 piece design gives more flexibility for working around the battery, and for access to the battery. I made a new lid, since the original had a stamped 'Taylor' across it, and I wanted a clean look. I did not think the battery hold-down clamp that came with the kit, nor the battery hold-down clamps that came with the battery would be secure enough, so I made a custom set of hold-down clamps for the base of the battery. I then used the Taylor battery clamp for the top of the battery.



Since this car is not a daily driver, I could down the car until completion, however, I wanted to be able to drive it at any time, so I took an order that did not disconnect the battery until last steps. I first laid out the new battery box location in the trunk. This involved removal of many of the carpeted pieces, then measuring for how tight I could get it to the gas filler and fender. Looking for as much usable trunk space as possible, I crammed the battery tight. At this point a decision had to be made, how much of the car should I cut-up, and what would be too much. In the factoring closeness, should I grind the flange of the fuel filler tube and the head of one of the fuel filler connecting bolts for tightness to the fender, or move the box away. I chose to grind. The box location was laid-out with blue tape. Also, used blue tape to mark where the original fender cover touches the trunk floor, to avoid setting the box or cables in that line. Setting the box bottom in place I marked the trunk floor for holes for the all-thread connecting bolts. Directly below is the fuel tank, which has to be dropped both for drilling the holes and for spinning and tightening the lock nut onto the all-thread connecting bolts. The right fuel tank strap had to be unbolted, but the left side only needed to be loosened (on a cobra, the left side is tight to the suspension, making it hard to get a socket on the head of the bolt).

The trunk floor was not smooth in the area to land the battery, with a caulk-line off one side, noise dampening on the other side, a drain grommet in the middle, then a sheetmetal stiffening groove just off-center. For better support, the trunk floor would need to be beefed-up in spots. Using some Dynamat, a flexible matting (can be worked like clay), I think made of butyl, to deadened the vibrations on sheetmetal commonly used for loud car stereo bass, I was able to fill the voids (doubling up in the groove) and make the surface closer to even.

After drilling the 2 holes, and removing the lay-out tape, the box bottom was ready to install. A cut-out was required on the carpeted fender cover before it would fit back in place. Since it is only carpet and fiberglass, a utility knife made an easy job of this.

Since the box is aluminum and the trunk is steel, the Dynamat also helped against dissimilar metals corrosion and electrolysis. As I added the all-thread bolts I added rubber washers, and used heat shrink tube around the threads to help against dissimilar metals corrosion and electrolysis. Before going any further the carpeted sidewall would have to be put back in place, there would be no room to squeeze it in after the battery or putting the battery box together. The cable was fitted behind where the carpeted fender cover would land. Specifically looking for non-chaffing, and the most tucked placement. At the back of the inner fenderwell, and in front of the fuel filler neck, a cut-out was made to relieve a space for the cables to come through. After doing the cut-out, a little paint would keep it from rusting, the potential sheetmetal chaffing point was then covered with a rubber edging designed for sheetmetal edges.

A spacer/backer was made for the clamps to hold the cables in a straight line. The end of the Negative cable was locked onto the seatbelt bolt, cleaning off the paint at the contact point. The placement of clamps was enough that the cable could not move, fastening each with tech (bit tipped) screws.

Two pieces of heat shrink tube was used to thicken the each of the cable ends in front of the lugs. A heat gun appeared to give the most even results.

After the cables were clamped across the fenderwell, and up to the back seat, the carpeted fender cover needed a little work. Grommets were tried to run the cable through this fiberglass shell, but the results were unsatisfactory, the fiberglass is thin and gave way too easily. I found connectors, called Cord Grip. Cord Grips with the washer backing on both sides were able to give a solid mount, even in the thin fiberglass. I modified the fasteners by adding a round-over to the back, then cut the pieces for a short throw on the backside, this gave a nice round exit for the cables. The Cord Grips hold (clamp) the cable in place as it runs through the carpeted fender cover.

Once the carpeted fender cover has been modified and re-installed, the battery and battery box can continue. Most of the cable was covered with the flexible black cable-shielding to further insulate and protect the cables. Nylon zip ties helped keep the cables packaged together. Wing-nut style battery clamps were used, this seemed better/quicker for any removal and reassembly. Wing-nuts were also used for the upper battery hold-down clamps and for the box lid.

The rest of the removed carpet was fit back into the trunk. So that the spare tire and trunk floor would be accessible, I did a cut-out (for the battery box) in the trunk floor carpet, instead of running the carpet under the battery box. The cuts were done with a straight-edge and a utility knife. Currently the Push-Lever has not been installed to the Disconnect Switch. I have left the Disconnect box loose and have about a 12 inch radius of cable flex to work with the way it sits. I have seen it run through the taillight, and could buy a spare taillight just for racing, but, not sure of which direction I will take at this time.

Next, was to continue down the lines, to the back seat. To open the bottom of the seat is as simple as pressing two buttons underneath the seats. One button can be found in the center of each seat. My hands were too big, using a Flat tipped screwdriver, I was able to press the buttons. Buttons press towards the back of the car. Pressing one button until it opens, then place something (like a putty knife) under the seat (by that button) so it won't re-clip itself while you're working on pressing the other button, made it easier. The seat back comes out with two bolts on bottom, then push the back upwards to unclip the clips. Please note, these instructions are for a convertible, which has seats that do not fold down. Other seats may have other removal procedures.

The cables were straight as the body allowed. The straightest path would keep the cable lengths to the shortest possible (in an attempt to drop the least current). Another cut-out was made to the seat back support bar to fit the cables under the bar, then the edge was covered with the rubber edging. For the front of the backseat, I chose to go through the cowl which supports the front of the seat. Since this cowl is contained, the Cord Grip fasteners could not be used (no access to the other side). Grommets were used instead, making sure they were tight to the holes and to the cable. WD-40 helped to work the cables through the tight rubber holes, so the grommets wouldn't be pulled out as the cable was pulled through the grommets.

The console removes with two bolts inside the glovebox, and two hidden under the shifter surround (this may differ for automatics). The shifter surround unclips with a gentle prying. In a convertible, disconnect the convertible up/down button power connector. Disconnect the lighter power connector. The emergency brake has to be pulled all the way back to remove the console. The emergency lever boot needed to be worked down the lever while lifting console. After the console was out of the car, both cables were tucked on the passenger side of the console under the carpet. Since this could be a place that passengers may negatively affect the cables, I used a seriously thick heat shrink tubing to cover the cables.

A splitter unit was installed on the passenger side in front of the center console for two reasons: 1) To split the power - one line to starter, one line to fuse box (stepped down to 2 gauge for these two split-off cables) 2) a convenient connection location in case of future install of electronics. The splitter used was found at a Marine supply. It is a simple unit, but it has much larger lugs than that was found at the car stereo stores.

After being passed through the splitter. all three cables are fed through the firewall next to the heater in front of the passenger's feet. Nylon zip ties helped in this tight spot.

In having a cobra, the room was extremely limited for working the engine side of the firewall. After looking around the firewall for some clear access, a clear spot was found on the firewall with very limited access to work on it underneath the AC condenser. All of the work was done with one hand (really too tight even for one arm). A dremel tool with an flex extension was of much help (couldn't even get a drill in there).

The Cord Grip fasteners were used through an aluminum plate and the firewall. Plate was butyl backed to seal the plate to the firewall. Due to the closeness of the exhaust manifold, the starter cable received some thermal protected cable shielding. The starter cable comes straight out of firewall. The fuse box cable and alternator cables turn upwards. A piece of rubber edging was use to cover the edge sticking out on the existing bent flat bar across the top of the firewall to prevent chaffing on the fuse box cable and alternator cables.

Due to tightness of the cables to the engine (heads and exhaust manifold), I cut a notch from the connecting tab of the upper and lower inner fenderwell to give the cord grips and the cables more room. With the lack of access to this area, I chose to make a slip-on holder for the cable clamp. This slip-on clamp slid onto the connecting tab of the upper and lower inner fenderwell. This held the shielded cable, where there was no access for a normal cable clamp install.

The fuse block cable and alternator cable were run up to the factory wire harness, then followed the harness across the top of the firewall. Taking advantage of a nice space behind the factory wire harness to tuck the new cables.

The original alternator cable, original starter cable, and original positive cable were completely removed, since to splice meant to step down in cable size. The original alternator rubber/plastic fitted-end cover was able to be re-used on the new alternator cable, therefore, keeping the end sealed from water, dirt, grease, but most importantly contact from a negative source.

The negative wire cluster that went around the battery, was able to be neatly tucked under the battery tray. The Kill-Switch was tested and killed the engine as it's supposed to.

Next, an upgraded heat exchanger, and fill the original battery holder with an upgraded heat exchanger overflow tank, made to use the original battery holder, some modification required ;).