Battery Swapping: Tesla’s Plan Includes Getting the Old Pack Back

By · April 28, 2011

Revenge of the Electric Car, Panel Discussion

Panel discussion following screening of Revenge of the Electric Car. (Photo: Rick Kim Photography)

One hundred miles. That’s the range of most electric cars, and if you want to go further, take the gas guzzler. But there’s a controversial alternative that can turn range anxiety vehicles into range champs: battery switching. Suppose you could drive 100 miles, take a quick detour into a switching station (five minutes or less), and take off again with a fresh pack? It’s more than possible—the technology is here now.

First championed by charging company Better Place in its bid to wire Israel, battery switching still induces much skepticism among automakers, and only Renault among mainstream automakers has embraced it (in Renault Fluence Z.E. cars for its partnership with Better Place). But Tesla is also planning switchable batteries for its new Tesla Model S electric sedan. That plan came under discussion last week at the Tribeca Film Festival premiere of Revenge of the Electric Car, which was followed by a panel that included Elon Musk of Tesla, Carlos Ghosn of Nissan, Dan Neil (a Wall Street Journal auto writer heavily featured in the film) and the filmmaker, Chris Paine.

The Model S will actually be introduced in a model with a huge battery pack (as much as 95 kilowatt hours) intended for 300 miles on a charge. That one won’t need to switch batteries too often, but there are two other editions with 160 and 230-mile range that could take advantage.

“We’re designing the Model S to have switchable batteries,” said Musk, who has a solution to the problem of consumers not wanting to end up with an unknown pack in their expensive EV. “When people take an occasional two-way long distance trip, they’ll get a replacement pack and then pick up their original one on the way back. The issue of giving up your one-year-old pack for a three-old-one goes away.”

I like that concept, for exactly the reasons Musk states. If I’d spent $77,400 on a Signature Edition Tesla Model S, I think I’d want to keep track of its ultra-expensive battery pack. Would you calmly swap engines on your Porsche?

Neil, whose Pulitzer Prize carries weight, is skeptical that swapping is viable. “The battery is the most expensive part of the car,” he said. “Does it really make economic sense to have these valuable packs lying around?” He also questioned Tesla’s ability to deliver on its every claim for the Model S, due out next year, and in the Green Room arranged a bet with Musk on the subject. Making the battery pack switchable definitely does add a layer of complication.

Ghosn countered that it’s no longer a question of “if” when it comes to swappable batteries. “Come to Israel and see for yourself,” he said. “In June we’ll be rolling it out on a massive scale.” Better Place has committed to buy 100,000 of the switchable-pack Renault cars, which are already on the ground in Denmark.

I know that battery switching works, because I saw Better Place do it in less than a minute in Tokyo with Nissan EVs. It’s completely automated, and very impressive to see. My personal view, though, is that it works best for single-model fleets such as taxis, buses or rental companies. There’s a central depot that could double as a switching station, and—best of all—one battery pack to stock, instead of the plethora that will be on the road in a few years.

Switching is a core part of the Better Place strategy, so it will get a pivotal airing from the company, just as the Revenge of the Electric Car is in full swing.

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