In accordance with an exemplary embodiment, an autonomous system is provided that includes: a tow vehicle, a trailer, and a control system. The tow vehicle has a vehicle battery. The trailer is coupled to the tow vehicle, and has a trailer battery. The control system includes a sensor and a processor. The sensor is configured to at least facilitate measuring a state of charge of the trailer battery. The processor is coupled to the sensor, and is configured to at least facilitate selectively providing current from the tow vehicle to the trailer based on the state of charge of the trailer battery.