How I built my own electric car
by Bill Williams

A couple of years ago I decided to be ready for any shortage of gasoline and considered converting my 1972 Datsun sedan to electric. It didn't take long to learn that the technology was available. I joined the local Electric Auto Assn. (EAA), whose 50 members have already converted over 20 autos to electric.

I was still a bit apprehensive about tearing apart a perfectly good gasoline car that was getting over 33 mpg in town. But fate played a part when the Datsun blew its head gasket. I decided in favor of conversion to electric rather than put more than $700 into it (the rings were also going) only to still be dependent on gasoline.

I went ahead full speed. First to go were more than 375 pounds of gasoline-related components (gasoline tank and lines, tailpipes, muffler, radiator, smog control, heater core, alternator, voltage regulator, starter, air cleaner and engine block). Nongasoline-related systems, like steering, brakes, hydraulic clutch, rear end, shocks, and interior components (like the speedometer) were left intact. The back seat was also retained for passengers (though with less legroom space to accommodate four of the total 12 propulsion batteries).

The truck compartment was then prepared for eight 6-volt (244AH) Trojan golf-cart batteries, weighing a total of 592 pounds. One extra leaf spring was added to the rear member to support the extra weight. Two safety devices were also installed in the trunk, a 400-ampere fuse and a large switch that could be manually turned off from the driver's seat. These two safety devices were then wired in series with cables routed beneath the car to the engine compartment. The trunk was finished off by installing the batteries (with steel clamp-down rack) and an electric plug in place of the gas-tank filler. Refueling would henceforth be with electricity.

While I was working on the trunk compartment, a fellow EAA member, Bob Steinfeld, was working on a special "adapter plate" for coupling the existing four-speed transmission to the d.c. electric motor (a 30-hp 2CM77 aircraft starter-generator). The adapter plate had originally cast to fit a Volkswagen transaxle, and therefore required custom machining to fit the current Datsun transmission. I considered retaining the four-speed transmission (plus reverse) a must, not only for flexibility, but also for the efficiency several forward gear ratios (3.757, 2.189, 1.404 and 1).