The Firefly product series is an application specific intelligent power bank for outdoor solar powered lighting purposes. During the day, the power bank converts the solar power and charges its internal battery. When day is over and sunlight stops, the stored energy is delivered suitable to drive a series of Light Emitting Diodes (LED string). The power bank keeps track of the energy harvested during the day and sets a sufficient LED current to spend as much energy as possible for lighting while being able to illuminate the entire night.

It inherits a very high efficient electronic converter that utilizes a novel method of combining electronic converters for both energy conversion modes (harvesting and illuminating).

The electronics inside features active maximum power point tracking and has specifically been optimized for a very high efficiency in the low power range for the solar energy harvesting mode making the system an efficient energy harvester even at cloudy days, and in partially shaded positions which is a key enabler in securing performance reliability. The built-in intelligence adjusts the converter for the attached solar panel and LED string and can thus be fitted in to various designs if the attached peripherals are within specifications.

A solar panel and an LED string are connected via the specified connector. The power bank will be activated when it senses sunlight on the solar panel and during the next night it will begin supplying power to the attached LED string.

The power bank needs 3-4 days to adjust to the lighting environment, the night length and the solar panel size before a predictable lighting scheme has been estimated by the built-in intelligence. Throughout the year the power bank adjusts its lighting scheme to the changing lengths of nights as well as cloudy or sunny days.