THE electrical energy of the LA301, the electric car recently unveiled by the Los Angeles Department of Water and Power (see story above), is stored by a 216-volt pack of lead-acid batteries under the rear seat. Considered maintenance-free, they are compartment-sealed against leakage even while upside down. One eight-hour charge via normal 110- or 220-volt outlets costs about $1 and will propel the car 40 to 60 miles. A three-pronged plug is accessible beneath the front hood.If the intended journey is no longer than 40 miles, drivers will select "EL" (electric mode) on a dashboard switch, which will run the car entirely electrically with zero emissions. Because designers feared such a limited-range car would be hard to sell - and present batteries can be made no stronger - John Samuel, director of engineering for CleanAir Transport, the Swedish company that makes the cars, says that a fuel-injected and catalyzed Japanese micro-car-type engine is included as an auxiliary power unit. For a journey up to 150 miles, drivers select "XR" (extended range), which allows the auxiliary engine to cut in at cruising rates greater than 30 m.p.h., regulated by computer. Such tandem use will help keep batteries from being discharged and lower the danger of motorists being stranded. With a seven-gallon tank, it will also extend the car's range to 150 miles and still meet California's strict guidelines for ultra-low-emission vehicles. In a third mode, "RR" (remote recharging), the gasoline engine can recharge batteries while the car is parked away from a socket. The computer controls power supplies to both motors, so there is no direct connection to the accelerator pedal. The car's two-speed gearbox regulates torque (engine force on wheels) while starting and cruising, making the ride far smoother than conventional cars. Drivers will meet with silence after turning the ignition key and again when shifting the car into "drive." But like an electric golf cart, the car will accelerate with a quiet "whoosh." Unlike conventional "epicyclic" automatic transmissions, the LA301 has a computer-run "synchro box" that may pause in neutral while the computer matches motor speeds to road speeds for new gear ratios. The electric motor can be used exclusively to top speed (75 m.p.h.). Lars Kyrklund, marketing director for CleanAir says the engine could easily go 90 to 100 m.p.h., but energy waste is higher at faster speeds, so the computer limits the speed. While driving, you can hear "clunks" and "thrums" as the computer controls use of the two engines for maximum mileage.