Tokyo Metro operates trains with battery backup since 2016. https://www.toshiba.co.jp/infrastructure/en/topics/back-number/20160614.htm https://www.toshiba.co.

Tokyo Metro operates trains with battery backup since 2016. https://www.toshiba.co.jp/infrastructure/en/topics/back-number/20160614.htm https://www.toshiba.co.jp/infrastructure/en/topics/back-numb...