Its torchlight function is very useful and effective. Indeed white LED only consumes 20 mA, so it will provide light for about 30 hours with a single charge of the battery, and with solar cells addition its life is practically endless. Of course you can also use this device to power your cellphone, your GPS logger, or any other little USB gadget (although battery has a reduced capacity due to its small size).
Step 1: The USB hub
Cut the circuit board in two and keep the smaller part with two USB sockets.
You can save remaining ports and USB plug for next projects.
Step 2: Solar cells and battery
The battery is a small flat Li-ion 3.7V battery for cellphones, these are not powerful as 18650 cells but they are very small and a great choice for a project like this.
I opened the plastic case and extracted the Li-ion cell, with its protection circuit. Keep half case as cover and safe protection.