A method for displaying power sustainability data for a battery includes providing a processor and a memory device coupled to the processor and receiving power sustainability data at a plurality of times. The power sustainability data includes a remaining battery capacity and a light exposure level. The method also includes storing the plurality of times and data values associated with the power sustainability data in the memory device. Additionally, the method includes obtaining most recently received data values for remaining battery capacity and light exposure level and displaying the most recently received data values for remaining battery capacity and light exposure levels.