An electric-vehicle battery (EVB) or traction battery is a battery used to power the propulsion of
Electric-vehicle batteries differ from
The battery makes up a substantial cost of BEVs, which unlike for fossil-fueled cars, profoundly manifests itself as a price of range. In the case of the MiEV 2012 model, the price tag and advertised range is close to proportional between two versions with a different battery,
 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
Rechargeable traction batteries are routinely used all day 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 (
Flooded lead-acid batteries are the cheapest and in past most common traction batteries available. There are two main types of lead-acid batteries: automobile engine starter batteries, and deep cycle batteries. Automobile alternators are designed to provide starter batteries high charge rates for fast charges, while deep cycle batteries used for electric vehicles like forklifts or golf carts, and as the auxiliary house batteries in RV's, require different multi-stage charging.  No lead acid battery should be discharged below 50% of its capacity, as it shortens the battery's life.  Flooded batteries require inspection of electrolyte level and occasional replacement of water which gases away during the normal charging cycle.
Traditionally, most electric vehicles have used lead-acid batteries due to their mature technology, high availability, and low cost (exception: some early EVs, such as the
Lead-acid batteries in EV applications end up being a significant (25–50%) portion of the final vehicle mass. Like all batteries, they have significantly lower
Charging and operation of batteries typically results in the emission of
Nickel-metal hydride batteries are now considered a relatively
GM Ovonic produced the NiMH battery used in the second generation EV-1, and Cobasys makes a nearly identical battery (ten 1.2 V 85 Ah NiMH cells in series in contrast with eleven cells for Ovonic battery). This worked very well in the EV-1.
The sodium or "zebra" battery uses a molten chloroaluminate sodium (NaAlCl4) as the electrolyte. This chemistry is also occasionally referred to as "hot salt". A relatively mature technology, the Zebra battery has an energy density of 120Wh/kg and reasonable series resistance. Since the battery must be heated for use, cold weather doesn't strongly affect its operation except for in increasing heating costs. They have been used in several EVs. Zebras can last for a few thousand charge cycles and are nontoxic. The downsides to the Zebra battery include poor power density (<300 W/kg) and the requirement of having to heat the electrolyte to about 270 °C (520 °F), which wastes some energy and presents difficulties in long-term storage of charge.
Lithium-ion (and similar lithium polymer) batteries, widely known via their use in laptops and consumer electronics, dominate the most recent group of EVs in development. The traditional lithium-ion chemistry involves a lithium cobalt oxide
Most other EVs are utilizing new variations on lithium-ion chemistry that sacrifice energy and power density to provide fire resistance, environmental friendliness, very rapid charges (as low as a few minutes), and very long lifespans. These variants (phosphates, titanates, spinels, etc.) have been shown to have a much longer lifetime, with A123 expecting their
Much work is being done on lithium ion batteries in the lab.
 Lithium vanadium oxide has already made its way into the