Final answer:
The DC BATTERY BUS is typically powered by a battery that provides a steady DC potential for the operation of various devices and systems. Transformers can be used to convert AC to DC for charging purposes as well. In the context of public transit, batteries need to be size and weight efficient.
Step-by-step explanation:
The DC BATTERY BUS is normally powered by a battery in various systems, providing a constant direct current (DC) potential that pushes charge in one direction through the circuit, thus creating the required DC current for operation. Devices often connect to a DC source, such as a battery, that can deliver a steady voltage.
Some systems may also use transformers to convert alternating current (AC) from a wall socket into DC to charge the battery that powers the DC BATTERY BUS. For public transit vehicles like buses, which are typically on the go for long periods, efficient energy solutions are crucial. Overnight charging can be practical for a fleet, but the size and weight of the batteries must be considered so as not to unduly burden the vehicles.