Electric battery common fuels such as gasoline. In automobiles, this is somewhat offset by the higher efficiency of electric motors in converting chemical energy to mechanical work, compared to combustion engines. The usage of "battery" to describe a group of electrical devices dates to Benjamin Franklin, who in 1748 described multiple Leyden jars by analogy to a battery of cannon (Benjamin Franklin borrowed the term "battery" from the military, which refers to weapons functioning together). Italian physicist Alessandro Volta built and described the first electrochemical battery, the voltaic pile, in 1800. This was a stack of copper and zinc plates, separated by
Plug-in electric vehicles in the United States a vehicle which draws propulsion energy from a traction battery with at least 5 kwh of capacity and uses an offboard source of energy to recharge such battery. The tax credit for new plug-in electric vehicles is worth plus for each kilowatt-hour of battery capacity over 5 kwh, and the portion of the credit determined by battery capacity cannot exceed . Therefore, the total amount of the credit, between and , will vary depending on the capacity of the battery (4 to 16 kWh) used to power the vehicles. The qualified plug-in electric vehicle credit phases out for a plug-in