The electrical system on Renfrow's Dodge must be as high-performance as the engine or suspension. It features an ignition system capable of firing a 700-horsepower engine at 9,000 rpm, and an alternator modified to withstand the rigors of racing.
With these unusual electrical demands and all the emphasis on improving the performance and reliability of racing parts, why do NASCAR teams use an off-the-shelf battery?
"A regular DieHard battery does everything we need," Myers said. "Most of the time, if there is a problem, it's not a problem with the battery."
In a sport where teams will shave down the lucky penny taped to the dash to save weight, how does Myers justify a DieHard that weighs 40 pounds or more?
"In a race truck, we mount the battery low in the frame on the left rear, where we want the weight anyway," he said. "A bigger battery has more lead and more acid and therefore more power. It will crank the engine and run the accessories longer, in case the alternator fails."
Even though production pickups often go 100,000 miles without repairs, NASCAR Craftsman Truck Series race trucks undergo "routine maintenance."After each race, the trucks are torn apart, inspected, tested and rebuilt.
But the DieHard batteries in Renfrow's Dodge don't need the routine scrutiny of weekly inspection.
"We put a new battery in each truck at the beginning of the year and check them regularly, but unless the truck is in a wreck, we don't change them," Myers said. "We have special trucks for each track, special gears to qualify and race, even special brakes and special lubricants, but just one battery - a DieHard."