GM Sees Fast-Charging, Not Battery-Swapping, Answer to EV Dilemma

SAUSALITO, CA – General Motors does not support battery-swapping as a solution to overcoming the recharging dilemma partly limiting the popularity of electric vehicles, saying the answer more likely is the nascent fast-charging infrastructure.

“We are not proponents of battery-swapping, not at all,” says Larry Nitz, GM global director-vehicle electrification.

“We feel if you are going to fill an electric vehicle, it will be through fast-charging. We are favorable to fast-charging,” he tells journalists at an event here laying out the auto maker’s electrification strategy.

Battery-swapping is seen by some as a valid means of solving the recharging dilemma. Many people want the fuel-saving and zero-emissions potential of an EV, battery proponents say, but not the headaches that come with charging durations that can last up to 14 hours on an 110V supply.

Even 220V connections reducing that time to eight hours hurts EVs, because it limits the distance owners can travel without a lengthy stop to recharge.

One potential solution: Set up stations where an EV owner could stop and swap his battery for another in the time it takes to fill a normal car or truck with gasoline.

Better Place, an Israeli venture, has been setting up battery-swapping stations in its native market, as well as Denmark and Australia. A membership in Better Place also provides access to plug-in charging.

But expansion of the Better Place network has moved slowly due to tepid global demand for EVs, and the company reportedly is experiencing financial distress. In the U.S., experts cite the limited potential for battery-swapping due to the country’s vast geography.

Nitz sees battery-swapping as an engineering and logistical nightmare. For starters, he says, the battery typically plays an integral role in the structure of the EV, so removing it presents challenges.

Swapping means disconnecting and reconnecting any number of high-power, low-power and thermal-management connections multiple times, which opens the door to a host of potential problems because every EV is engineered differently.

The ’13 Chevrolet Spark EV arriving at dealers next year, for example, houses its 20kW (27-hp) lithium-ion battery from A123 Systems under the rear seats. In that position, it replaces the fuel tank found on an internal-combustion-powered model with few modifications so customers will not to have sacrifice comfort or cabin space.

“With the Spark, you’d have to take the rear axle out to swap it,” Nitz says. “So it’s just not a practical opportunity.”

OEMs might share cell technology, but every battery pack is designed differently, as well, he adds, so the number of batteries needed in circulation for swapping would be enormous. “If I aggregate that, it is a logistics nightmare.”

Pam Fletcher, GM global chief engineer for the Chevy Volt extended-range EV and plug-in hybrid powertrains, says even the Chinese government that once was bullish on the idea of battery-swapping has backed off its enthusiasm.

Fletcher recently returned from a tour of the China Electric Vehicle International Demonstration Zone in the Jiading District of Shanghai, where the focus is on enhancing and integrating EV technologies in a community. Charging stations from General Electric are the dominant battery-filling method.

“China thought it was all about battery-swapping, but they’ve moved away from it too,” Fletcher says. “Too many entities need to coordinate to make it happen, so I think the real enabler, the real tipping point, will be when charging starts to resemble your experience at the gas station.”

That would mean fast-charging.

The Spark EV comes to market in California and South Korea next year as the first electrified vehicle from GM with an industry-first combination charging portal permitting direct-current fast-charging to 80% of battery capacity within roughly 20 minutes.

The Mitsubishi i EV, a direct competitor for the Spark, uses an extra charging portal to accommodate DC fast-charging.

But as sold as Nitz is on fast-charging for a quick battery fill-up, he still considers overnight charging, combined with increasing availability of workplace plug-in stations, as the smartest strategy for an EV owner.

“The thing that comes out clearly is to charge at home at night, 110V or 220V, charge at work, and I’d say spot fast-charging as needed,” he says, citing his Chevy Volt-owner daughter as a prime example.

“She doesn’t burn gas. She plugs in every night, no problem,” Nitz says. “I plug in my cell phone every night, and she plugs in her car every night. It’s not a big deal.”

GM also announces at the event successful collaboration with power-industry supplier ABB on a project demonstrating EV battery reuse, repackaging five used Volt battery packs into a stationary power unit capable of providing up to five residential homes with upwards of two hours of electricity.

Early findings show when EV battery packs reach end-of-life as an automotive application, only 30% of their overall life has been used.

GM’s idea would provide a secondary use and provide homes or businesses with backup power in case of an outage. It also would allow for power storage during times of low demand for use during peak periods when electricity is most expensive.

Additionally, stationary power units could be used to “fill the gaps” during solar, wind or other renewable power generation, GM says.

ABB will continue proof-of-concept testing, market research and product development of the stationary units.

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