For years now, some electric vehicle advocates have argued that despite the higher up-front cost of batteries, plug-in cars would be cheaper to own and operate in the long run. The problem was, until the Tesla Roadster came along a couple of years ago, there were no factory-built and sold electric vehicles (EVs) to gather any real evidence from. The real test will begin in the next few months when Nissan, General Motors, Mitsubishi, Ford and others start to sell EVs to the masses.
Two big factors really can't be argued against right now. Even with government incentives, EVs will be more expensive to buy than an equivalent internal combustion vehicle and energizing them from the grid will cost less. However, one of the big arguments against buying most new cars, regardless of power plant, has been that they lose a good chunk of their value as soon as you drive them off the lot. The rate of depreciation varies widely and is often connected to how well they hold up after several years on the road. A typical car might be worth half or less of its original value after just five years.
How will this affect plug-in cars? With an EV, the battery pack often accounts for a much larger percentage of the car's original value other types of vehicles. While an engine that has been maintained properly can easily exhibit most of its original performance after 100,000 miles – and many can often go 200,000 miles or more – the same cannot reliably be said (yet, as far as we know) of a battery in an EV. The reality is that no one really knows how much value a battery will retain after 50,000 or 100,000 miles. It's a hard number to calculate. Nissan has said that the Leaf battery might only hold 80 or 70 percent of its original charge after ten years, for example, which will make it worth less. Speaking to the BBC, Mitsubishi has acknowledged that the i-MiEV's depreciation over three years could turn out to be more than the original cost of an internal combustion car (a Fiat 500 Lounge 1.2 petrol, in the example given). That's a tough bunch of numbers.