GM Shows Off 'The Rest of It,' Unveils Volt Charging Systems at Plug-In Confab
By John O'Dell August 11, 2009
By John O'Dell, Senior Editor
It's not as exciting as General Motors Corp.'s announcement this morning that its Chevrolet Volt is likely to win a 230-mpg fuel economy rating from the EPA for city driving, but the automaker's plan for charging the extended-range hybrid may be more meaningful.
Engineer Gery Kissel explains GM's dual charging options to journalists at Plug-In 2009 conference.
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The latter, GM executives said at a dinner last night held in conjunction with the Plug-In 2009 conference in Long Beach, Calif., is likely to be offered as an option, to be permanently installed in an owner's garage, carport or even an outdoor location.
GM's spent a lot of time talking about the car, its features and its design, "now here's the rest of it," Volt vehicle line director Tony Posawatz said as he pointed to the display stand on which the two systems were mounted.
A Homebody
"We've geared the Volt to be charged at home...if the infrastructure [for public charging] catches up with it, fine, but it won't be a necessity," he told Green Car Advisor.
When that public infrastructure is in place, GM will have a number of options available for Volt owners, including fast-charging systems, he said. He added that the automaker has several teams working on ideas to make the Volt as user-friendly as any conventional car in order to help people accept, adopt and adapt to a vehicle that uses electric drive and rechargeable batteries.
The principal charging system for the Volt is likely to be the 110-volt system - that's the most common type of outlet in most homes in the U.S.
But Posawatz (right) said he expects most buyers to purchase the much faster 240-volt system as well and to install that as their fixed-base charger while using the 110-volt system as a portable or emergency charger carried in a special compartment built into the Volt's trunk.
Tokyo Says 'Use the 240'
Posawatz didn't refer to it, but earlier in the day Takafumi Anegawa, manager of Tokyo Electric Power Co.'s electric vehicle program, said that in tests the company has been running with EVs made by Mitsubishi and Subaru in Japan (Nissan's Leaf EV will join the test program when it is launched early next year), the utility determined that even for tiny city cars with small battery packs a 110-volt system was impractical for everyday use because charging takes too long.
GM figures 3-4-hours to recharge the Volt's batteries on the 240-volt system, and 6-8 hours on a 110-volt system.
The 240-volt system won't fit in the trunk compartment, but that's okay because national electrical codes require the system to be a permanent installation, hard-wired to the incoming power source rather than attached with a wall plug.
That's not because authorities fear that Americans will fry themselves right and left with a 240-volt system, but rather than the wall plugs available (think of the triple-pronged plug on an electric clothes drier or electric oven) aren't designed to be inserted and removed hundreds of times as could be the case with a portable 240-volt car-charging system.
Universal Connector
The system GM engineers designed for the Volt features a spiral-coiled, international orange charging cord that is stored by manually winding it around a circular cord-holder and "info center" affixed to a garage or house wall or mounted on a pole.
The cord snakes from the mounting to the car's charging port, attached by a universal "J1772" charging connector that not only transmits juice to the batteries but contains a pair of communication links so the car and the charger can keep in touch during the recharging process.
One of the links tells the Volt's charging apparatus what kind of amperage is in use (the system is user-selectable so amperage can be lowered if charging causes a household circuit-breaker to trip, shutting down a dryer, TV or other appliances).
No Drive-Aways
The other tells the car that it is connected to the charger and triggers an automatic engine shut-down if someone tries to drive away without disconnecting the charging cord.
Both the 240- and 110-volt systems contain the communications links, said GM engineer Gery Kissell.
The 110-volt system is basically a lighter-weight version of the 220-volt, with a thinner, straight cord that is attached via a wall plug so it can be unplugged and stored in the car.
In the garage, the cord would be coiled around a wall-mounted holder that also would be removed to serve as a cord-carrier if the system were to be used as a portable.
It, too, would use the J1772 nozzle, which all U.S. car chargers will use. In addition to its universal attachment and communication link system, the connector features a cover that can withstand being run over by a full-sized car without breaking to expose wiring.
Power to the People
GM's design also incorporates a small light at the end of the connector nozzle that can serve as a flashlight to illuminate charging ports and storage clips in dark locations.
"We're really trying to make sure we've anticipated all the needs a consumer might have," said Posawatz.
To that end, he said, the coiled cord on the 240-volt system is likely to be changed to a straight cord before production - the coils collect dirt and grease and make the cord difficult to hold, he said.
Asked why there wasn't an automatic cord winder with the system, Posawatz smiled and launched into an explanation that illustrates the planning GM engineers have done.
Not Designed in a Vacuum
"When was the last time you saw a vacuum cleaner with a retracting cord," he asked. "They all used to have them, but none do now. We had vacuum-cleaner engineers come in and picked their brains."
Automatic cord-coilers, the engineers said, are unreliable - and coiled cords generate heat when in use.
"If you had a coiled charging cord on a 240-volt system and you never pulled it all out straight, it could get so hot it would melt stuff," said Posawatz.
One cure being considered is to make the cord in varying lengths and to let customers installing 240-volt chargers choose the length that would be best for their needs.
And yes, said Kissel, the charging system can be used in the rain; the car could even be washed while hooked up to the charger.
"You could dunk this in a bucket of water," he said, displaying the
connector nozzle, "and you'd be okay."
Good to know.
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