Apparatus, systems, and methods described herein relate generally to autonomous mobile units carrying a modular configurable battery system that may attach and power mobile units in transportation systems. A method can include determining charge levels, current positions, and transport speeds for an electric vehicle (EV), identifying one or more EVs in need of charging, and mobilizing a Mobile Charging Station (MoCS) to deliver one or more external batteries. A processor, with a memory including computer program code, can be configured to receive current charge level data for mobile battery-powered entities, identify one or more EVs to be charged and the proximity of both MoCS and physical battery stations, and send charging instructions to the EVs. A routing and charge transaction scheduling algorithm can be used to optimize the route of one or more battery-powered entities and to schedule charge transactions between the EV and MoCS and/or the battery station.