Batteries

An electric vehicle battery (EVB) or traction battery is a battery used to power the propulsion of a battery electric vehicle (BEVs).

A (BEV), battery-only electric vehicle (BOEV), or all-electric vehicle is a type of electric vehicle (EV) that uses chemical energy stored in rechargeable battery packs. BEVs use electric motors and motor controllers instead of internal combustion engines (ICEs) for propulsion.

Vehicle batteries are usually secondary (rechargeable) batteries. Traction batteries are used in forklifts, electric Golf carts, riding floor scrubbers, electric motorcycles, full-size electric cars, trucks, vans, and other electric vehicles. Electric vehicle batteries differ from starting, lighting, and ignition (SLI) batteries because they are designed to give power over sustained periods.

Deep cycle batteries are used instead of SLI batteries for these applications. Traction batteries must be designed with a high ampere-hour capacity. Batteries for electric vehicles are characterized by their relatively high power-to-weight ratio, energy-to-weight ratio, and energy density; smaller, lighter batteries reduce the vehicle’s weight and improve its performance.

Compared to liquid fuels, most current battery technologies have much lower specific energy, which often impacts the vehicles’ maximum all-electric range. However, metal-air batteries have extraordinarily high power because the surrounding oxygen in the air provides the cathode. Rechargeable batteries used in electric vehicles include lead-acid (‘flooded,’ Deep cycle, and VRLA), NiCd, nickel metal hydride, lithium-ion, Li-ion polymer, and, less commonly, zinc-air and molten salt batteries. The amount of electricity (i.e., electric charge) stored in batteries is measured in ampere-hours or coulombs, with the total energy often measured in watt-hours.

The battery makes up a substantial cost of BEVs, which profoundly manifests as a price of range, unlike fossil-fueled cars. In the case of the MiEV 2012 model, the price tag and advertised content are close to proportional between two versions with a different batteries, giving the (false) impression that the battery makes up close to 100% of the cost (95% for the higher priced version). However, some of the price difference comes from extra features in the higher-priced version, plus an unknown price premium, making such a retail price comparison a terrible indicator of the actual cost of battery capacity but serves to quantify battery capacity as a premium feature.

The few electric cars with over 500 km of range (including the Tesla Model S with the 85 kWh battery) are firmly in the luxury segment as of 2015. Since the late 1990s, advances in battery technology have been driven by demands for portable electronics, like laptop computers and mobile phones. The BEV marketplace has reaped the benefits of these advances. However, Mitsubishi ascribes the price reduction of its 2012 model MiEV, compared to the 2011 model, to a dramatic decrease in the cost of batteries.

The cost of electric vehicle batteries has been reduced by more than 35% from 2008 to 2014. Rechargeable traction batteries are routinely used and fast–charged all night. Forklifts, for instance, are usually discharged and recharged every 24 hours of the work week. The predicted market for automobile traction batteries is over $37 billion in 2020.

On an energy basis, the price of electricity to run an EV is a small fraction of the cost of liquid fuel needed to produce an equivalent amount of energy (energy efficiency). The cost of replacing the batteries dominates the operating costs.

See the types of batteries by system:

They derive all power from battery packs and thus have no internal combustion engine, fuel cell, or fuel tank. BEVs include bicycles, scooters, skateboards, rail cars, watercraft, forklifts, buses, trucks, and cars. Since the introduction of the all-electric Nissan Leaf in December 2010, about 1 million highway-legal plug-in electric vehicles have been sold worldwide by mid-September 2015, of which about 620,000 are all-electric passenger cars and light-duty trucks. The best-selling all-electric car in history is the Nissan Leaf, with sales of 200,000 units worldwide by early December 2015, followed by the Tesla Model S, with global sales of 100,000 units also by early December 2015.

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