Click here to read the full article from Csaba Csere at the New York Times
Multimedia
WITH electric cars and plug-in hybrids at last trickling into the showrooms of mainstream automakers, the dream of going gasoline-free is becoming a reality for many drivers. Cars like the Nissan Leaf and the Chevrolet Volt can cover considerable distances under electric power alone — certainly enough for local errands and even most daily commutes — while enabling their owners to shun gas stations.
Indeed, charging the car’s battery pack at home, or topping up at the office or shopping mall, will work fine for most drivers. But what about trips that are beyond the range of a single battery charge? Couldn’t a driver in need simply pull up to a charging kiosk and plug in for a rapid refill?
It’s not that simple.
Sure, there are already public charging stations in service, and new ones are coming online daily. But those typically take several hours to fully replenish a battery.
As a result, the ability for quick battery boosts — using a compatible direct current fast charger, the Leaf can refill to 80 percent capacity in 30 minutes — could potentially become an important point of differentiation among electric models.
But the availability of fast charging points has in part been held up by the lack of an agreement among automakers on a universal method for fast charging — or even on a single electrical connector. Today’s prevalent D.C. fast-charge systems are built to a standard developed in Japan by Nissan, Mitsubishi and Subaru in conjunction with Tokyo Electric Power.
Called Chademo, which translates roughly to “charge and move,” it uses a connector that is different from the plugs in most electric cars. As a result, a Chademo-compatible car like the Nissan Leaf requires two separate sockets.
Overcoming the limitation of a short driving range is vital to achieving acceptance by consumers who want uncompromised, do-everything vehicles. The potential solutions all have drawbacks. Larger batteries are expensive and saddle the car with added weight. An onboard generator turned by a gasoline engine, as used in the Volt plug-in hybrid and similar future models, are another possible solution, but such systems add cost and pounds — and compromise the emissions-free image that attracts consumers to electric cars in the first place.
Leisurely overnight recharging is no problem. All electric cars come with a standard charging cable that can plug into a common 120-volt household electrical outlet. More than just an extension cord, this cable incorporates various safety features.
“There is no energy flowing through the cord until the car talks to the box,” said Gary Kissel, an engineering specialist for General Motors, referring to the charging cord’s electronics. “It also has a G.F.C.I. and signals the car that the cable is connected, making it impossible for you to drive off if you forget that you’re plugged in,” he said, using the abbreviation for the safety provision known as a ground fault circuit interrupter.
The Leaf and the Volt, as well as future electric cars coming to the American market, can use these 120-volt cords interchangeably because they are all designed to the SAE J1772 standard. A task force assembled by SAE International, an organization of scientists and vehicle engineers, developed the design specifications for the J1772 standard through a committee of 150 carmakers, electrical equipment makers and utilities.
Other groups, including the American National Standards Institute, are also working on standards and codes for electric cars.
Posts
No comments:
Post a Comment