Headlamp assembly with selectable power source

A headlamp assembly, comprising:

• a first power source and a second power source;
• a front head assembly including a first housing, a light-emitting diode (LED), a power switch, the first power source, and a charging port;
• a rear battery pack assembly including a second housing, the second power source, and a pivoting arm that enables a front surface and a rear surface of the second housing to pivot relative to one another to expose the second power source, wherein the front head assembly and the rear battery pack assembly are electrically coupled to one another;
• and
• a selector switch, wherein the selector switch is configured to select between the first power source and the second power source to power the LED.

A headlamp assembly, comprising:

• a first housing configured to be worn on a front surface of a head of an operator, the first housing comprising a light-emitting element and a rechargeable power source;
• a second housing separate from the first housing that is configured to be worn on a rear surface of the head of the operator, the second housing comprising a disposable power source, the second housing being electrically coupled to the first housing, wherein the disposable power source is not rechargeable;
• and
• a selector and circuitry configured to toggle power provided to the light-emitting element between the disposable power source and the rechargeable power source based at least in part on an orientation of the selector.