A comparison of different types of batteries of the same weight in our EV Plus: lead, lithium, Nickel Metal Hydride (NiMH, our battery), and zinc-air reveals that zinc air is the best battery. However, unless the infrastructure for zinc-air becomes available, the best battery currently available is the NiMH. Zinc-air would be far superior, but of all the rest, NiMH is best.

The de facto standard for electric cars is the NiMH battery developed by Energy Conversion Devices (Nasdaq: ENER). This company was founded by Stanford R. Ovshinsky, President and CEO. The Chairman is Robert C. Stempel, the former head of GM. ENER has recently formed a business alliance with Lee A. Iacocca's EV Global, which is partnered with Unique Mobility (AMEX: UQM), which made the 5 motors for the hybrid-electric HumVee. We hope for continued good news from this association.

The Honda EV+ has two electrical systems: high voltage to drive the car, and low voltage for the radio, headlights, and other accessories. The high voltage battery's nominal voltage is 288, and is "isolated" from the car for safety. The battery has a rated capacity of 90 amp-hours, yielding 26.1 kilo-Watt Hours (kWH) of energy storage. For comparison, a gallon of gasoline "holds" about 33 kWH of potential energy. Typical range for the EV Plus is 100 miles using some 80% of the battery capacity, or approximately 22 kWH. Thus the efficiency of the car in familiar terms is equivalent to

33kWH
---------- X 100 = 150 miles per gallon
22 kWh

The current NiMH batteries store about 70 Watt-Hours per kilogram of battery weight (WH/kg) of electric storage, and can perhaps be improved to 120-150 WH/kg. Sony is working with Lithium Ion batteries in the 90-120 WH/kg range, which can perhaps be improved to 250 WH/kg. The Electric Fuel Corporation (Nasdaq: EFCX) currently makes zinc-air batteries for powering vans which contain 210 WH/kg, and are committed to producing 400 WH/kg zinc air batteries.