Patent ID: 8104915

Claim:
A flashlight comprising: a light generation element configured to be powered by a battery held within the flashlight; a circuit coupled to the light generation element including: a memory configured to store battery life information for the battery, wherein the battery life information includes a battery life of the battery and includes voltage output information of the battery over a time of use of the battery to power the light generation element, a controller configured to operate as a count down timer to accumulate an amount of time that the battery provides power to the light generation element to light the light generation element, and a voltage measure circuit configured to monitor the voltage output by the battery while the battery provides power to the light generation element to light the light generation element and supply voltage information for the voltage output to the controller; wherein the controller is configured to i) determine a first remaining battery life for the battery via comparison of the accumulated time to the battery life, ii) determine a second remaining battery life via comparison of the supplied voltage information from the voltage measure circuit to the voltage output information of the battery over time, and iii) determine the lesser of the first remaining battery life and the second remaining battery life; and a display coupled to the controller and configured to receive a command from the controller to display the lesser of the first remaining battery life and the second remaining battery life.