A story is breaking in the world of Electronic Vehicles about an owner of a fabulously expensive Tesla Roadster (a very light two seater sports car with an electric motor and a huge battery). It’s a pretty fast and nice bit of kit.
Unfortunately the manual of the car makes it painfully clear that if you ever let the battery go completely flat you’re in deep trouble. It’s the Electric Car equivalent of taking a new engine, running the revs up to maximum in neutral with your foot flat on the floor until something goes pop.
I’ve been in the computer business for a while. I’ve sold tens of thousands of laptops all with batteries almost identiical to those in modern elecctric cars: lithium ion. If they ever go completely flat, by being left in a drawer for 6 months, they’re completely dead. Annoying if it’s a $100 battery in a laptop or an iPod. Rather more painful if it’s the $40,000 component in your sports car. I have customers bring in year old $200 net book computers that they stuck in a drawer six months ago and now they’re pissed off when I have to tell them a new battery is $120. There’s just nothing else I can do.
The moral of the story applies to all modern electronic devices with lithium batteries: keep ‘em topped up. If you’re storing them for a while take them out and charge them up every couple of weeks.
It’s even worse: electric cars don’t have a clutch or gearbox like a normal car so the wheels are directly connected to an electric motor. Getting them to turn if you can’t somehow get power to the motor is going to be very hard.
Which would be why the Tesla’s user manual makes it very clear that you should always leave your car plugged in. If you can’t do that then it tells you how fast the battery looses power but basically leaving it unplugged for more than 2 weeks has a good chance of getting dangerously expensive.
Just watch for this to be another stick to beat up on electric cars. You heard it here first.