Electric cars have been around for surprisingly a long time. They were first developed in the 1880's and remained popular until the early 20th century when the internal combustion engine gained dominance. There have been other resurgences in the electric car when the fuel crisis of the 1970's and 1980"s happened but, there were relatively short lived. The problem with electric cars is twofold: distance between charges and the speed of the vehicle. But in recent years, with an even more acute awareness that fossil fuels are finite resource plus the advances in battery and engine technologies there is resurging interest. Obviously, the mass car manufacturers are investing in electric car companies such as Mitsubishi, Smart, Volvo, and Ford. But, the new kid on the block who is taking the U.S. by storm and ruffling a few features in the process is Tesla Motors.
Elon Musk and four others founded Tesla Motors in 2003 with a goal of mass producing commercially affordable electric cars. 2,250 have been sold so far and although not expensive compared to luxury cards, they are expensive compared to other gas fueled cars. But, the really cool thing about Telsa cars is the technology that they use to provide an extended range (265 miles) and a high top speed (125 mph) and the fact that in June 2014, Elon Musk released their patents to the open source movement. This blog won't discuss how absolutely amazing it is that Telsa won't send lawyers after anyone that uses its technology in good faith. If you are interested in that topic, read this article.
The point of this blog is to highlight the technical bits of the motors and the batteries that enable their cars to reach speeds in excess of 120 MPH and to go for over 250 miles on a single charge. Inside each Tesla car there are fours systems: Energy Storage System (ESS), Power Electric Module (PEM), electric motor, and a sequential manual transmission.
The ESS is a fancy name for batteries. The batteries in the Tesla are rechargeable litium-ion, the type used in laptops. There are nearly 7,000 of them and they weight an amazing 1,000 pounds and Tesla claims that provides "four to five times the energy-density storage of other batteries". The batteries are stored in 11 sectors each of which is controlled by a separate processor. This makes charging and discharging a lot more efficient. From your home, a special 220 volt, 70 amp outlet can be installed and will recharge a fully dead battery in just 3.5 hours or a mobile kit is available which will recharge the car from any power supply: still a lot slower than a gas car but faster than their competitors.
The PEM converts the DC power being sent to the car by the main power supply into AC power by using 72 generated bipolar transistors (IGBTs). This means that the power output is increased to 200 kW but the PEM does more than that, it's also responsible for controlling the voltage levels, the motor's RPM, torque, and the regenerative braking system.
If the weight of the batteries made you baulk, then perhaps the weight of the motor will make you happier. At just 70 pounds, this three phase four pole electric induction motor is considerably lighter than it's combustion counterparts. The speed, torque, and acceleration are impressive and the Tesla website says "A favorite trick here at Tesla Motors is to invite a passenger along and ask him to turn on the radio. At the precise moment we ask, we accelerate. Our passenger simply can't sit forward enough to reach the dials". This amount of torque is unique amongst electric cards never mind combustion engine vehicles.
Electric card are making huge strides forward and Tesla aren't the only company making them take a look at this comparison chart to see other models.