Old Anvil Speed Shop Increases Our 1948 Chevy’s Voltage With XS Power

By Rob Fortier – Photography by Taylor Kempkes

For as long as I’ve been around cars and motorcycles, you’d think that my specific knowledge of and skillset with wiring would be rather advanced. Nope. Don’t get me wrong, I understand basic electronics and have even wired a couple full vehicles, but there are specifics about automotive electrical systems (even the older ones) that are not in my realm of expertise—if there is such a thing to begin with?!

Among the numerous items on the laundry list of to-dos that Old Anvil Speed Shop is handling on my ’48 Chevy, wiring was not one of them … until I walked in the shop one day and Paul says to me, “We’re installing dual batteries—we need a pair of Group 34 AGMs.” Even though I’d just installed a brand-new battery in the stock location (under the passenger-side floorboard), I didn’t want to question Paul, but ultimately I had to ask “why?”

003 Overview of the truck bed chassis with a mounted custom fuel tank

In preparation for the installation of the Air Lift Performance 3H/3P air management system, “… the dual ViAir 485C compressors draw as much as 46 amps combined. Without dual batteries, this draw can create a voltage drop to other components, such as EFI, stereos, and fuel pumps, as well as overload the alternator,” Paul explains. OK, so that means I’ll also need to upgrade my alternator, correct? “No. Actually, the dual batteries help the alternator a lot—they take the load off peak needs, like when the compressors are on. When they are off, it’s storing energy—kind of like solar panels with power storage.”

004 Underside view of a truck chassis with a custom mounted fuel tank

OK, so now I understand the dual power source situation and proceeded to order up a pair of A3400 AGM batteries from XS Power (1,000 cold cranking amps with a 2,500- to 4,000-watt range … each), which Paul would wire using 1/0-gauge welding cable and single 100-amp relay with a 60-amp MIDI fuse for the compressors. But, my next question was, where you going to put both batteries?!

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005 Sparks flying from a grinder during metalwork on a truck frame

Well, as some of you may or may not know, Old Anvil is quite proficient with CNC—from small parts and complete wheels to full bed floor frames and, you guessed it, billet battery trays. If it can be imagined, chances are they can whittle it out. With the old manual-valve air-ride system removed from the rearmost portion of the chassis, Paul chose to locate the Old Anvil Group 34 battery mounts on each side of the fuel tank via a custom-fabbed subframe structure, which I had absolutely no problem with!

Once we finish up the BedWood and Parts curly maple bed floor with Old Anvil’s VIP All Access articulating bed floor (and Legens Hot Rod Shop fuel access kit), we’ll put these new XS Power batteries to use with the aforementioned Air Lift FLO Air kit! Stay tuned!