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No Fast-Charging for Volt as GM Questions Need


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No Fast-Charging for Volt as GM Questions Need

By Tom Murphy

LOS ANGELES – The modern age of electric vehicles has arrived, but that doesn’t mean high-voltage charging stations need to be as prevalent as gasoline stations today, a General Motors Co. executive says at the auto show here.

Buyers of new electric vehicles have three charging options:

Use a standard 120V wall socket, and the state of charge can go from zero to 100% in about 20 hours. A dedicated Level II charging station operating at 240V capacity can do the job in less than half the time.

Lastly, high-powered 480V DC fast chargers, about the size of a gasoline pump, are being installed across the country, supported by U.S. Department of Energy grants intended to foster establishment of an adequate infrastructure to support EVs.

These devices can charge an EV in about 30 minutes, providing a security blanket of sorts for buyers of all-electric vehicles, such as the Nissan Leaf, that lack gasoline engines to keep the wheels turning when the electricity runs out.

GM’s Chevrolet Volt has a gasoline engine to power a generator to run the vehicle when the battery’s charge has been depleted. But it was designed specifically not to accommodate a 480V fast charge, says Britta Gross, director-GM’s Global Energy Systems & Infrastructure Commercialization unit, based in Warren, MI.

“The goal was to make the Volt as invisible to the (electrical) grid as possible,” Gross tells Ward’s. The Volt plugs into a standard household outlet and also can use a 240V dedicated charging station – each method employing the new standard J1772 electrical connector.

But GM was less interested in fast-charge capability for the Volt because those units create a tremendous load on the electrical grid, she says.

In illustrating that impact, Gross says the Volt’s dedicated charger uses a 240V line with a capacity of 16 amps, allowing 3,300 watts of electricity to feed the battery. At even lower levels, a standard 120V wall socket with a capacity of 12 amps allows 1,100 watts for charging.

Eaton makes 480V “EV Quick Chargers” and 240V standard charging docks (pictured at center) for upcoming Mitsubishi i-MiEV, on display at LA auto show.

By comparison, a DC fast charger uses a 480V line with a capacity of 100 amps, allowing 50,000 watts of power to surge into the battery on a 3-phase line, hence the rapid charge.

Repeated cycles with these high-output devices will impact battery life, Gross says.

“It’s just another very rapid cycle of a battery, and batteries don’t want to be rapid-cycled and don’t want to be deeply discharged. You have to control it to 80% of the charge,” she says.

“And with rapid charging, there’s a lot of heat loss. It’s not something you do in residential areas. It’s definitely industrial, maybe heavy commercial.”

Despite GM’s concerns, the rapid-charge devices are on the way.

Energy-storage supplier ECOtality Inc., based in San Francisco and partnering with Nissan Motor Co. Ltd., will install its Blink DC Fast Chargers as early as March at 45 BP and ARCO service stations in Arizona, San Diego, Los Angeles, Oregon, Seattle and Tennessee.

Those markets also will be the first to receive the Nissan Leaf EV, which has a connector to receive a 480V charge.

ECOtality is the project manager for The EV Project, an initiative that will place about 15,000 electrical stations – some of them fast chargers – in 16 cities and major metropolitan areas, and will place 8,300 EVs on the road.

GM’s 240V “Voltec” unit used to charge Volt.

The DOE is funding the program with a $115 million grant. Private investments bring the total value of the project to about $230 million, according to ECOtality.

Supplier Eaton Corp. manufactures 480V fast chargers and also supplies 240V charging docks for the Mitsubishi i-MiEV, a 4-door EV similar in size to the Leaf and going on sale in the U.S. late next year. A production version of the new EV is on display at the auto show here.

Like the Leaf, the i-MiEV has a J1772 connector for standard charging and a larger port for fast charging.

Nissan spokesman Brian Brockman says the vision for DC fast charging is to help consumers manage the use of their EVs and overcome range anxiety. The stations can deliver a quick boost around town, and on the highway they can provide essential refueling stops for road trips.

Nissan sees DC fast chargers as an important piece of the infrastructure for zero-emission vehicles to gain widespread acceptance.

But GM’s Gross says fast-charge stations raise as many questions as they answer. “You have to figure out where you’re willing to stay for 30 minutes to get the full charge,” she says.

A mall or restaurant could be a convenient location for such a device. “But I keep asking myself, ‘Why isn’t 240V service satisfactory, even at a restaurant or a mall?’”

During a 4-hour trip to the mall or perhaps during a football game, a Volt plugged into a 240V dock could take a full charge (it takes about 10 hours on a standard wall socket) without causing undue stress on the grid, Gross says.

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But even for pure EVs, plug-in hybrids and extended-range electric vehicles, Gross still questions whether 480V charging docks are overkill.

“I wonder, to stop for 30 minutes for a rapid charge of the battery, is that really something we want to be doing to our vehicles,” she says.

Cost is another big concern. Gross says the rapid-charge docks cost at least $30,000 apiece, and installation adds another $15,000 to the tab. Eaton says its Quick Charger will go on the market in early 2011 with an MSRP of $64,000, plus installation.

“Someone’s got to pay for that,” she says, questioning whether consumers of the service will be gouged.

By comparison, a 240V charging dock, smaller than a laundry basket and designed by GM, is available to Volt buyers from SPX Service Solutions, priced at $490. Home installation will cost about $1,500, depending on whether the electrical service needs significant upgrading.

Other logistical questions arise with regard to 480V charging stations: What happens when two drivers show up at the same time? Will heated arguments between hurried motorists become commonplace?

Is a manager necessary to decide who goes first and to shuttle vehicles through the charging process, so consumers can use the time for walking to lunch or the post office? How much will people pay for electricity delivered with such speed?

Despite her concerns, Gross says she understands the need for fast chargers and views their pending installation as “a real demonstration program. Let’s see what a difference it makes in those five regions. Let’s see how often they are used and what it means to the grid.

“Let’s learn from this. Then maybe I will be smarter; maybe a lot of us will be smarter about whether or not that’s a good, sound investment.”

If the only way consumers will purchase EVs is if they can rely on a fast-charge unit in an emergency, then the devices may enable the next phase in automotive mobility.



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