The factory battery location...
The factory battery location is prime real estate in a Mustang's engine compartment. On modified 'Stangs, batteries typically are relocated to the back, allowing the OEM space to be used for mounting intercooler tanks, ignition boxes and such, or simply left bare for a cleaner, less-crowded underhood appearance.
Making 'Stangs fast is an interest shared by many and most avid Mustang enthusiasts. Anyone who follows our monthly reports knows we're certainly motivated by go. But despite our penchant for big-time power, the show side of the late-model-Pony experience has a special place in our hearts, too. With that said, a Pony's appearance and presentation come to the forefront this month as we introduce a new battery-relocation kit that really helps clean up some of the clutter in a Fox-body Mustang's engine bay.
The Fender Mount Battery Box...
The Fender Mount Battery Box (PN 7998BB; $249.95) is highlighted by an 11.5x9x8-inch, 14-gauge-steel, powdercoated basket that accepts Optima's Group 34-model batteries (not included). The box is topped by an aluminum lid that can be ordered with a brushed or powdercoated finish. Fastening hardware, Scosche power/ground wires, and a pair of Scosche battery terminals also are included with the kit. We're using a 750-CCA Yellow Top cell (PN 8012-021; $215.99) for this project, but you should consult Optima's website for assistance selecting the battery that best suits your needs.
For years, moving a 12-volt battery cell to the trunk or hatchback area of a Mustang has been a normal practice for those who are setting their Ponies up for racing or harvesting valuable underhood real estate.Relocating the battery also played a big role in improving a car's display characteristics. There's nothing like seeing a good-looking engine sitting in the confines of a smoothed firewall and finished inner-fender panels that are free of the many holes whose purpose we've never been able to understand.
Over the years, we've come across a few show- and magazine-quality Ponies sporting power cells that have been taken from their OEM trays (the trays are discarded, of course) and placed inside the driver-side inner fender. Seeing this modification as a finished product is way cool, but until now, the science behind achieving this look has been a complete and total mystery. Kdezines Audio of Tuscon, Arizona (www.kdezines.com), and AMP Performance have removed all the guesswork from performing this custom mod, and your tech editor was treated to an exclusive look at how to get it done; a bonus for TI that came during his recent tech session with the crew at AMP.

After removing the OEM battery...

After removing the OEM battery and the driver-side front tire, and pulling back the inner-fender plastic, Keith Doughty of Kdezines Audio uses the relocation kit's backing plate as a template and traces an outline for the opening that must be cut in the fender panel. On '90-up Mustangs, wiring for the airbag sensor also must be relocated from its position on the panel.

Once the outline is made,...

Once the outline is made, a hole is cut for the battery basket. An air nibbler, tin snips, or a plasma cutter help make this an easy procedure.

Once the opening is made in...

Once the opening is made in the panel, establishing perfect fitment for the battery box is a trial-and-error process that may require a small amount of trimming. In some instances, the horn assembly (mounted on the frame behind the panel) may require relocation, too. The fender support is a good spot for this.

A total of eight small (5/16-inch)...

A total of eight small (5/16-inch) holes are required for the anchoring studs (supplied) that secure the basket. A 1/4-inch backing bracket is used to sandwich the inner-fender panel between it and the top plate on the basket, which further secures the battery box to the panel.

With the addition of new power...

With the addition of new power and ground wires and battery terminals from Scosche, this is how the fender-mounted battery looks in the engine compartment of a Fox 'Stang. Sure, the rest of the engine bay of this project car is a little rough now (the car is in the process of a makeover), but we think this is a cool and different upgrade for those who want to move a Pony's battery without taking it to the trunk.
The all-new Fender Mount Battery Box (PN 7998BB; $249.95) is a well-designed, comprehensive system that allows '79-'98 Mustang owners to mount an Optima 12-volt battery inside the driver-side fender of their rides. The photos and captions follow Keith Doughty as he demonstrates the clean setup, which installs in about three hours with just a small collection of tools.