BatteryThe Gen I EV1 models, released in 1996, used lead-acid batteries, and weighed in at 3,086 pounds (1,400 kg). The first batch of batteries were provided by GM's Delphi branch; these were rated at 53 amp-hours at 312 volts (16.5 kWh), and provided the initially range of 60 miles per charge. Gen II cars, released in 1999, used a new batch of lead-acid batteries provided by Panasonic; some Gen I cars were retrofitted with this battery pack. The Japanese batteries were rated at 60 amp-hours (18.7 kWh) at 312 volts, and increased the EV1's range to 100 miles. Soon after the rollout of the second generation cars, the originally intended nickel metal hydride (NiMH) "Ovonic" battery pack, which reduced the car's curb weight to 2,908 pounds (1,319 kg) entered production; this pack was also retrofitted to earlier cars (both battery pack designs were led and invented by John E. Waters under the Delco Remy organization). The NiMH batteries, rated at 77 amp-hours (26.4 kWh) at 343 volts, gave the cars a range of 160 miles (120 to 240 km) per charge, more than twice what the original Gen I cars could muster.
It took the NiMH-equipped cars as much as eight hours for the cars to charge to full capacity (though an 80% charge could be achieved in between one and three hours). The Panasonic battery pack consisted of twenty-six 12 volt, 60 amp-hour lead-acid batteries holding 67.4 megajoules (18.7 kWh) of energy. The NiMH packs contained twenty-six 13.2 volt, 77 Ah nickel-metal hydride batteries which held 95.1 megajoules (26.4 kWh) of energy.