New Lead-Acid Battery Helps Improve EV Range 23%

New Lead-Acid Battery Helps
Improve Electric Vehicle Range 23%

June 21, 1996
San Dimas, CA

A 4-passenger AC Propulsion electric vehicle equipped with Optima lead-acid batteries traveled 145 miles on one charge today setting a new mark for EVs in a test witnessed by Southern California Edison. The 145 mile range is a new record for the SCE Pomona test course. The previous record was 120 miles held by the Ford Ecostar using sodium-sulphur batteries. The previous best for lead-acid powered EVs had been 118 miles, also set by AC Propulsion using an earlier version of the Optima EV battery. The best performance by any other lead-acid powered EV over the Pomona Loop is 85 miles. The demonstrated 145 mile range also exceeds the ranges claimed by Honda and Toyota for their nickel-metal hydride battery powered EVs introduced in April at Eco Expo in Los Angeles, which were both less than 130 miles.

The 145 mile range was achieved with the same AC-150 electric drive system that powers the Ohio State and Oklahoma entries in the Cleveland Electric Formula Classic Race this weekend.

AC Propulsion president Alan Cocconi, who drove the car for the test attributed the 23% range increase primarily to improvements Optima has made to its EV battery. "We used our demo car that has 47,000 miles on it, and didn't change anything for this test," said Cocconi. "After we installed the new batteries in April, we began to realize that they had significantly more capacity than Optima's previous generation of EV battery. We are getting over 100 miles at 65-70 mph, and that's without any special attention to efficient driving technique. We wanted an independent test for verification, and that's what we got today."

The range test was conducted on Southern California Edison's Pomona Loop, a route designed by SCE to represent typical driving on suburban streets. Run at posted speed limits, this loop requires a faster, somewhat more aggressive driving pattern than the US Federal Urban Driving Schedule which is used to determine fuel economy ratings for conventional cars. The AC Propulsion EV, with driver and passenger on board completed 7.5 laps of the 19.4 mile route for 145 miles with an average enerrgy consumption of 126 Wh/mile.

The Optima EV battery is similar to the starter battery that Optima produces at its Colorado factory for aftermarket and racing applications. It uses the same sealed, spiral-wound construction but requires specific formulations for the electrolyte and electrode materials. "Tailoring changes for the EV application is where Optima is really making progress," Cocconi observed. "The range and battery life just keep getting better, but the important factor for me, as an EV constructor, is that these batteries are presently available in initial production runs at a price I can afford, and have demonstrated 30,000 mile life in actual daily use. Some advanced batteries promise even greater range, but with them, actual price and availability are unknown.

The AC-150 electric drivetrain is a 150 kilowatt (200 horsepower) electric motor and controller for vehicles in the 2500-4000 pound weight range. It embodies advanced motor control, battery charging, and driver interface circuitry and control logic to provide high performance, high efficiency, recharging, and battery management functions in an integrated package. The AC-150 is manufactured in California by AC Propulsion Inc.