The film ”Who Killed the Electric Car?“ claims that some sort of political agenda coupled with an addiction to foreign oil have prevented the adoption of electric cars and their development.  Electric cars, in fact, have been around before the gasoline-engine (to be covered in a future article) and they did not die off with General Motors EV1.  Despite what the aforementioned documentary film may say, there is no conspiracy preventing the development of electric cars, rather it is a limitation of available battery technologies. For this reason, most automotive companies are turning towards other technologies such as fuel cells as the next alternative fuel source (to power electric cars).  To prove my point about current technology limiting electric vehicle production, I will use an example of the much publicized Tesla Motors Roadster and explore its practicalities. 

Tesla Motors has been making news everywhere about their Roadster sports car.  With performance matching a Lamborghini (0 to 60 mph in 3.9 seconds) for a fraction of a price and style almost identical to a Lotus Elise, it’s no wonder this car has been making headlines.  The electric motor is a 3-phase, 4-pole electric motor capable of delivering 248hp peak (185kW) — in other words, it has serious power.  “Through electromagnetic induction, the rotating magnetic field induces a current in the conductors in the rotor, which in turn sets up a counterbalancing magnetic field that causes the rotor to turn in the direction the field is rotating” (Wikipedia).  It cuts down on weight by using an aluminum chassis.  The range is fairly good as well at 250 miles.  It runs at an efficiency of 200 watt-hours per mile, or equivalent of 135 miles per gallon of gasoline.

However, I’m predicting that several problems will prevent this car from widespread adoption; the same problems that the GM EV1 encountered, and the same problems that battery powered electrical vehicles will continue to face.  The Tesla Roadster uses 6,831 lithium-ion battery cells which weigh a total of 450 kg.  Despite the fact that they’ll provide a 50 kWh capacity, they present a huge problem.  Lithium ion batteries, like any other battery, loses capacity over time and if the batteries are stored at high temperatures (lets say a car sitting in the sun), they’ll degrade even faster.  The degradation can range any where from 6% per year (stored at 0°C) to 40% per 3 months (stored at 60°C) (source: Battery University). Unless they plan on cooling the batteries all the time, we’ll be seeing rather high degredation rates. Let’s say, best case scenario, the car loses 15% of its charge after the first year, it’ll be down to a 213 mile max range on a charge in its second year.  By the time you get to your fifth year owning the car, the range will be less than 150 miles.  The batteries are also very expensive, so replacing them every few years is not a practical solution.  However, at some point (Tesla Motors is claiming 10 years), the batteries will have to be replaced.  At 450 kg, this creates a HUGE amount of waste. In addition to the aforementioned concerns about lithium-ion batteries, they also can rupture, ignite, or explode when exposed to high temperatures.  Internal contaminants can defeat safety devices that protect the cells from damage, furthermore leading rapid discharge of heat (ie. fire) or an explosion.  Should you ever get in an accident with the Tesla Roadster, damage to the batteries could have catastropic effects.

The second major problem is the cost.  At $89,000 for the base model, the Tesla Roadster is out reach for the typical consumer, however Tesla Motors was smart by offering exploiting the high torque provided by electric engines and marketing the Roadster as sports car.  This allows them to grab a much larger demographic; the first 100 production units have already been sold.  The production of the Roadster will very limited, and still has another year before we see it country-wide.

Battery powered electric cars like the Tesla Roadster and GM EV1 prove to be unpractical due to the characteristics of current battery technologies.  Until researchers get all the kinks worked out with fuel cells, we’ll continue to have these prototype battery powered electric cars that show the potential of electric cars, given the right power source.