Replaceable batteries: Pipe-dream or the future for electric cars?

In the race to develop a low-carbon replacement to the internal combustion engine, the electric car has always had something of a handicap. Whilst we are used to refilling petrol engines in a minute or two, the standard time to charge a car-sized lithium-ion battery is 8-10 hours (reports of a 10-minute charge time seem a little far-fetched).

Hence the excitement about Better Place’s battery-switch technology, unveiled last week in Japan. The Silicon Valley startup has developed a $500,000 prototype ‘shuttle’, which can remove a dead battery and have the car back on the road with a fresh one in around 80 seconds, without anyone needing to get out of the car at all.

This would greatly increase the usability of electric cars, but raises at least two further challenges.

The first is that Better Place’s vision needs a dense infrastructure of ‘Switch Stations’, creating a chicken-and-egg scenario whereby the technology can’t take off until the infrastructure is in place, but there is no incentive to develop the infrastructure until the technology has been widely adopted. This negates one of the great advantages that electric cars have over, say, hydrogen fuel-cell vehicles.

The second difficulty is that for the technology to work the auto industry would need to standardise the batteries they use for the next generation of vehicles; something akin to putting the same engine in a hatchback and a sports car. Wired is sceptical, apparently based on comments from two leading automakers.

Resistance from the auto industry shouldn’t come as a surprise. At around $10,000, batteries are a significant portion of an electric car’s value, and Better Place’s business model would require a consumer to rent the batteries, rather than purchase them along with the car. By implication, the manufacturer is selling a less valuable product.

This may be overstating the problem, however. As production ramps up, the price of a battery is likely to fall dramatically – some analysts predict a drop of two-thirds by 2010-11. It is also easy to imagine a small number of battery makers becoming dominant, with swap stations offering each type of battery – much like fuel stations currently offering three or four types of fuel.

Lastly, the auto industry is in such a poor state at present that standardisation of battery technology may be a small price to pay to access what could soon be a swiftly growing market.