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Tesla launches battery-swapping service for two-minute recharging

June 21, 2013

All eyes have been on California-based electric car maker Tesla Motors in recent months, with the company having turned a profit last quarter and earning numerous awards for its Model S luxury sedan. And as promised, Tesla on Thursday night demonstrated an automated system capable of recharging the Model S in less than two minutes — equivalent to the time it takes to fuel up a gasoline-powered car.

And by “recharging,” we mean replacing.

As in, dropping a Model S’ depleted battery pack — which can weigh half a ton — out from the undercarriage of the vehicle and replacing it with a fully charged one. Think of it as pulling up to a filling station and instead of sticking a hose into the filler cap and refilling your empty tank, simply replacing the empty gas tank with one that’s full of gas. Only in this case, the gas station is a Tesla Station (a.k.a. a Tesla Supercharger station) and the “gas tank” weighs more than 1,000 pounds.

Tesla previewed the fully automated process at its Hawthorne, Calif., design studio. There are no pumps to pay and the driver never even has to exit the vehicle. Simply pull into the Tesla Station, locate the battery swap spot, follow the on-board prompts, and the battery-swapping machinery takes over from there.

Sitting in a pit in the ground beneath the car is a fully charged battery, which the system prepares for installation as it locates its vehicle’s existing battery pack bolts. The bolts are then unscrewed with the help of “high-precision nut runners,” allowing the existing pack to be lowered into the pit, then the new pack moves into position and is inserted into the car’s body. The bolts are tightened again, and away the car goes.

The whole process takes just over a minute and a half, or about half the time it takes to fill up the average automobile. The customer’s credit card (provided beforehand) is charged automatically. How much? Tesla Motors CEO Elon Musk vows that the cost of the pack swap will be set near the local price of 15 gallons of gasoline, or between about $60 and $80, depending on location.

But the transaction doesn't end there. Customers will be required to return the battery to the same station on their return trip, at which point they pay the same amount to have their old (now fully charged) battery reinstalled. If there is no return trip, customers may pay to have their battery transported to them and swapped back in at a different location. If the customer wishes, he or she may even keep the battery pack and pay the difference in value between their used battery and the new one — which could run to thousands of dollars depending on the age of the car.

The battery swap service will be available through the growing network of Tesla Stations which currently offer free high-speed charging services (less than an hour) to Tesla owners. By comparison, Tesla’s high-power home chargers take about seven hours to recharge a depleted Model S battery, you’ll need more than a day to get a full charge from a meager 110-volt household plug.

Tesla vows to have 27 Tesla stations in place covering much of California and the Boston/Washington corridor by the end of the summer. Battery swap components will be phased in starting in California by the end of the year, and will cost Tesla roughly $500,000 per location to install. Initially, up to 50 batteries will be stored at a given battery swap location.

Noteworthy is that all Model S vehicles built to date will be able to use the system, as the battery pack was designed from the beginning to be swappable. Likewise, customers of the upcoming Model X crossover will also have access to the battery swap service, since the big battery packs are common to them. Tesla’s planned smaller model will use a smaller pack, and Musk did not specify how he planned to handle battery swaps with that model, noting that charging technology continues to evolve at a fast pace, and that battery pack swapping may not even be relevant at that point.

As we have noted before, battery swapping is hardly a new idea, but to date, no company has been able to implement it in a viable way. Perhaps a guy who runs a company that makes rockets will have better luck getting the idea off the ground.