The problem with battery trains is that locomotives hardly sit around long enough to charge unless it's some sort of switcher or in for maintenance. Really the only use case for battery locomotives outside of switchers is passenger service where it's fairly common for a train to sit for eight plus hours. Amtrak and Siemens are actually doing this with 15 of the new airo trainsets which will run on the empire line. The trainsets will specifically run on battery while within the new York city tunnels where diesel locomotives are only allowed to operate under emergency.