Battery electric multiple unit

A battery electric multiple unit (BEMU), battery electric railcar or accumulator railcar is an electric multiple unit or railcar whose energy can be supplied from rechargeable batteries driving the traction motors. Prime advantages of these vehicles is that they do not use fossil fuels such as coal or diesel fuel, emit no exhaust gases and do not require the railway to have expensive continuous infrastructure like electric third rail or overhead catenary.

Source: Wikipedia — Battery electric multiple unit (CC BY-SA 4.0)