The very main difference between an electric vehicle and a gasoline driven car is its power plant. An electric car uses an electric motor to generate torque to move the vehicle while a conventional car uses an internal combustion engine. An electric motor does use gasoline for power, instead it uses electric current. To supply the power to the motor, a series of batteries are used. An electric vehicle (EV) would need up to 15 to 20 units of battery. On a full charge, the EV would able to cover approximately 150 miles. Unfortunately, after some time, the battery would lose its stable capacity therefore reducing the EV mileage. Why does a battery efficiency drops after some time? This article will provide some information on the subject.
Most batteries are made up of plates inside, that when left in an undercharged state becomes sulfated. That means that they develop a layer of sulfate crystals on the surface of the plates. When the plates are covered by the sulfate, there are less surface contact between the metal and the distilled water. This will restrict the flow of electron in the battery. When the plates are fully covered by crystallized sulfate, there is no electron movement at all before killing the battery.
Apart from the electric motor, the battery bank is one of the largest expenses in a Do It Yourself (DIY) electric car conversion project. There are ways where you can recondition a dead battery for EV. The process can be dangerous and would be a better idea to outsource it to a professional.