Wednesday, July 29, 2009

Battery Swap


One of the limitations of electric vehicles today is the recharge time. There are several ways to solve this problem. Just like you would do with a battery powered toy, one of the solutions is battery swapping. You pull into a swap-station and faster than you could fill a combustion car with gas, your vehicle has a fresh, fully charged battery pack and you can head on down the road.


Better Place is an EV charging start up active in Israel, Denmark, Australia, Canada, California and Hawaii. Better Place founder and CEO Shai Agassi, said they have installed their first battery swap station in Yokohama Japan. Agassi said the stations will look a lot like a car wash. The “pancake style” battery pack is located under the vehicle, out of crash zones and does not interfere with passenger or storage spaces. Keeping the pack underneath also gives the vehicle a low center of gravity. Better Place has developed a “patented latching mechanism” to swap the battery pack.

Here is a video of how the swap system works.


At first, I did not like the idea of battery swapping. As an EV driver, I take measures to not abuse my batteries. The idea that I could get a pack that has been abused concerned me. If they are not 'your' batteries, some people are more likely to treat them like a rental car.

After meeting with Better Place, they alleviated these concerns and pointed out other benefits of swapping in addition to the quick fill-up. One, the packets all undergo diagnostics after they are extracted. Only packs that pass muster are charged up for future use. Failing packs are set aside for maintenance or replacement. Two, batteries are currently a rapidly evolving technology. As new innovations are brought to market, they can be put into new swap packs and you get more range. If you buy a car with a fixed pack, you won't get these upgrades unless you buy a new battery pack or car.

Tesla has said that battery swapping has been a subject of much "deep thinking." Unfortunately, Tesla has no plans to invest in a battery-swap system as part of the Model S' plan.

In another video below, you can see how battery swapping could fit into a day of EV driving with overnight charging at home for commuting, Level 2 charging at work and battery swapping for longer trips.

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