What shape will the plug for recharging your future electric vehicle take?
That question is becoming a pressing matter for automakers. The global auto industry has yet to agree on a standardized shape for the connectors that will replenish the batteries of electric cars, though the Society of Automotive Engineers has been working on standards for such a plug for more than two years.
Issues of this sort must be resolved before many of the electric powertrains displayed at the Detroit auto show this month will be able to take to the road in large numbers. While the breadth and diversity of electric car proposals seen in Detroit seemed to affirm their inevitability — despite obstacles like US$0.52 per liter gas at nearby pumps and a grim car market overall — the efforts at electrification of the vehicle fleet, to use the buzz phrase of the moment, also raised awareness of the challenges that automakers will face.
Making the electricity available to recharge batteries is just one of the hurdles carmakers must address. How far the cars will go on a charge, how long the recharging process will take, and even how drivers will be billed for electricity when they recharge away from home, are also matters that engineers are scrambling to sort out.
David Champion, director of auto testing at Consumer Reports, said that the promises being made for electric cars are sure to lead to some buyer disappointments. Commenting on vehicles he saw at the Detroit show like the Chevrolet Volt — a plug-in hybrid with a 64km all-electric range, which General Motors says will go on sale late next year — he noted that the ranges are mostly predicated on low speed and intermittent city driving, where an electric powertrain shines.
“You get that vehicle out on the highway and cruise along at 70 miles per hour [112kph], that range is going to plummet,” Champion said.
The Volt’s powertrain design, generally referred to as a series hybrid, incorporates a gasoline-driven generator that can keep the car going until it can plug in for a recharge.
Add the amenities that Americans expect in their cars — air-conditioning turned up high, audio systems set to deafening levels — and battery-powered vehicles may be spending as many of their kilowatt hours on comfort as they do on cruising.
The issue puts pressure on engineers to reduce charging time. In news conferences during the show’s press preview days, the hours-to-recharge figure seemed to be the newest bragging point for some automakers, replacing zero-to-60 times and fuel-efficiency ratings as the numbers that mattered.
The Mini E, for instance, can be recharged in just 2.5 hours using a special home charging station. The battery-powered Minis — 500 are being leased to individuals in the Los Angeles and New York metro areas for one-year terms — can also be recharged on household current. But if the current comes from a standard 110-volt wall socket, it will take 23 hours to restore the car’s 240km maximum range.
Public charging stations were announced for the Smart Electric Drive cars that are part of a 100-vehicle Berlin test fleet to be put on the road this year. The stations include a link to a computer chip in the car that allows charging with the lowest-cost electricity, choosing off-peak times, and possibly even selecting green energy sources by detecting when wind farms or solar panels are feeding to the energy grid.