US Patent 9346397 Self-powered light bar

An emergency system for a vehicle integrates many disparate equipment into single housing, including the power supply for the equipment. In one embodiment of the invention, the emergency system is a light bar. The light bar houses a power source comprising solar cell panels, a Lithium-Ion battery pack and a connection to an external supply such as the vehicle's electrical power. Energy for operating the light bar is provided by one or more of the power sources, depending on operating conditions of the light bar and each of the power sources.