What is the life of the battery?

We have found that the battery will last a minimum of 22 hours, but this is dependent on how many devices are being powered by it. We found it lasted approximately 22 hours when powering three devices, 48 hours when powering two devices and upwards of 4 days when only powering one device. This may also vary depending on how many taps it receives and if it is being used in colder temperatures.