How long do the batteries last in an electric car?

Battery life in an electric car is largely dependent on what type of batteries are being used in the vehicle. There are many different kinds of batterys but for current electric cars only five types are commonly used in electric vehicles. Battery life in cars is measured in cycles rather than time or distance traveled.

A battery cycle is one charge and one discharge and the number of cycles is usually expressed as a range because how the battery is used and charged can have a great effect on it's life.

Lead-Acid - This is the oldest form of chargeable battery. Lead-acid batteries were invented in 1859 and are still the type used is most internal combustion engine cars today. The deep cycle vareity of lead-acid battery is the type commonly found in electric cars today. Lead-acid batteries are the least expensive of the five types, they also have the lowest energy to weight ratio and will usually last for 500-800 cycles.

Nickel-Cadmium (NiCd) - Nickel-cadmium batteries, commonly pronounced "nye-cad" are the rechargeable battery that we encounter most often in our day to day lives. Power tools, portable electronics and electric toys all use NiCd batteries because of their long life and low cost. With a 40-60 Wh/kg (watt-hour per kilogram) energy to weight ratio and a life cycle of around 2000 cycles they are a good, inexpensive source of power for electric cars.

Nickel-Metal Hydride (NiMH) - A slightly better energy to weight ratio than NiCd at 30-80 Wh/kg and an absence of the toxic element of cadmium makes these batteries the choice of some electric car manufacturers. Nickel-metal hydride batteries have a life of about 800-1000 cycles.

Lithium-Ion (Li-Ion) - This is the battery that's most likely powering you laptop or other battery powered consumer electronics. An extremely effecient 100-160 Wh/kg energy to weight ratio makes these the battery of choice in most high power/low weight applications. The Tesla Roadster uses Li-Ion batteries to keep it's powerful electric car as light as possible. Lithium-ion batteries have a life of approximately 1200 cycles.

Lithium Polymer (Li-Poly) - The next step in battery evolution from lithium-ion, the litium polymer battery has an energy to weight ratio as high as 200 Wh/kg. Not commonly available in electric cars due to their high cost, they are gaining favor among manufacturers due to their high power. The battery life of a lithium polymer battery is around 1000 cycles.

So you can see that battery life is affected by how often you fully discharge and recharge the batteries. Running the battery nearly all the way down and fully charging it will put the life of your electric car batteries at the lower end of the spectrum.

No comments have been provided.