The Smart BEST is an experimental Japanese two-car self-charging battery electric multiple unit (BEMU) train developed and manufactured by Kinki Sharyo in 2012 to demonstrate the feasibility of battery train technology for use on non-electrified rural lines.
The name is an acronym for "Battery Engine Synergy Train".
The train has been tested on JR West and JR Shikoku lines since late 2012.
The Smart BEST train operates using GS Yuasa LIM30H-8A lithium-ion storage battery modules recharged in operation by a small-capacity "e-Brid Plus" diesel engine.
The train normally operates at a maximum speed of 70 km/h (45 mph), but is capable of 100 km/h (60 mph) over short distances.