The BYD K-series bus are a line of battery electric buses manufactured by the Chinese automaker BYD, powered with its self-developed lithium iron phosphate battery, featuring a typical operating range of 250 kilometres (160 mi) per charge under urban road conditions. It is available in several different nominal lengths, from 7.0 to 13.7 m and also as a 18 m (60 ft) (articulated) bus. The rear axle is powered by two electric traction motors; the battery capacity and motor power of each model varies depending on the nominal length and passenger capacity.

A battery electric bus is an electric bus that is driven by an electric motor and obtains energy from on-board batteries. Many trolleybuses use batteries as an auxiliary or emergency power source.