Normal electric trains already carry batteries for this reason, and to be able to manuever off the track in case of a power outage. Much like trams. There's a

Normal electric trains already carry batteries for this reason, and to be able to manuever off the track in case of a power outage. Much like trams. There's a big difference however between a train with a short term battery backup and one that rides on pure battery power for an extended range.