Fuente: WIPO "sustainability" A method for determining a power sustainability status of a device having one or more solar panels and a battery includes receiving a request to indicate the power sustainability status, measuring a voltage of the battery, and determining a usage level of the device and a low power sustainability threshold. The method further includes computing a remaining capacity of the battery using the voltage of the battery and usage level of the device and computing a light exposure level associated with the one or more solar panels. Additionally, the method includes determining a power sustainability index using at least one of the remaining capacity of the battery or the light exposure level and comparing the power sustainability index to the low power sustainability threshold.