I posted last week that creating "recharge stations" would extend the distance an electric car can travel. But now that I think about it, I'm not so sure. The difference isn't just swapping out gas for electric -- charging a battery takes more time than filling a tank. How much time? Well, it depends on the battery. But think about how long it takes to charge your computer, or your iPod, or your phone -- several hours. It's possible to "speed charge" a battery, but it will ultimately decrease the battery life, damaging the battery. So unless electric car owners are prepared to spend three hours at a rest stop or similar waiting for their car to charge, road trips are out of the question.
Perhaps a solution would be for electric car owners to carry a spare battery and exchange it out when one gets low, the way that some people swap out laptop batteries or similar. However, then we run into the problem of size and weight. Where are you going to fit that spare battery? The Roadster has a system of 6800 cells, each about the size of a AA battery, all adding up to about 450kg. That's not the sort of thing you can cart around in your trunk and swap out at will.
Not to mention that all rechargeable batteries gradually wear out over time, their life slowly decreasing until ultimately they will no longer hold a charge and must be replaced.
It makes sense, if you think about it. Consider: my laptop (a relatively new machine) has a lithium-ion battery rated at 85WHr. It's about the general size of my forearm, and rather heavy. Compare that to 53kWh -- that's KILOwatts, a thousand times greater -- on the Tesla Roadster. Now, obviously we're comparing apples and oranges a bit here, but if the technology existed to make large batteries tiny safely and at an affordable price, wouldn't that have expanded into the field of portable electronics? You can't get more bang for your buck, so to speak, not with current technology.
And lithium-ion batteries, while they offer good performance, run the risk of thermal runaway. Remember on the news a while ago, that recall on Dell batteries? Because they were CATCHING FIRE?
(image from geekologie.com)
Yeah. That.
Obviously not going to happen with electric cars -- we hope. Tesla Motors, at least, has considered the problem and acted pre-emptively to make sure they're safe. But it goes to show you. Nothing's free when it comes to energy: try to make a smaller, more powerful battery, and you produce more heat. Faster charging may mean you have to replace the battery sooner. New technology costs money, and that cost will carry on to the consumer. But if we don't switch to an alternate fuel for our vehicles, we'll just keep burning through gasoline until there's none left. There is no solution that does not require a trade.
The question is, what are we willing to trade?
Check out project "Better Place."
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