Systems and methods for backup power sources and controls for Power over Ethernet light sources are provided. In one example embodiment, a lighting system includes one or more light sources configured to receive power over one or more Ethernet cables. The lighting system also includes a battery pack comprising an energy storage medium. The battery pack can be configured to provide power to the one or more light sources over one or more Ethernet cables. The lighting system can also include an output control circuit configured to manage delivery of power from the battery pack to the one or more light sources.