The OBC’s main function is to manage the AC-to-DC conversion process safely and efficiently, adapting to different charging levels and monitoring the voltage and current to protect the battery’s health. This flexibility allows EVs to connect to a wide range of charging sources, from Level 1 home chargers with standard 120V outlets to Level 2 public chargers with higher voltage. As a result, OBCs are especially important for everyday charging needs, offering a practical solution for drivers who charge overnight at home or during longer stays at public charging stations.
However, because of their design, OBCs generally do not support high-power, rapid charging that is often needed during long-distance travel. DC fast chargers bypass the OBC entirely, delivering DC power directly to the battery at much higher rates, reducing charging time significantly. This setup allows the OBC to be optimised for everyday, moderate charging needs, while DC fast chargers can meet the demands of quick, high-power charging.
As EV technology advances, manufacturers are continually improving OBC efficiency, reducing its size, and increasing its power handling to allow for faster AC charging rates. Future developments may include bidirectional charging capabilities, which would allow the OBC to not only charge the EV but also send energy back to the grid or to other devices, enhancing the vehicle’s role in smart energy systems and grid support applications.