Abstract: A light mountable on a handlebar of a vehicle, and including a light unit, including a light-emitting element, such as an incandescent bulb or light-emitting diode, and a battery housing for containing at least one battery for supplying electricity to the light-emitting element and a mounting on which the light unit is carried. The mounting is adapted for adjustable attachment to a handlebar. A secondary battery pack housing is carried by the mounting for containing a battery, and includes an electrical interconnection with the light-emitting element. Alternatively, the battery pack housing may be the sole source of electric current for the light-emitting element.