The four small bars indicate the battery power and the charge status of the Power Bank. The external battery can be easily charged with the included cable to the laptop or PC. Gleizeitig can then be downloaded on the go with this cable the smartphone or tablet. In our opinion the small battery is quite heavy, so you should therefore really consider whether you are constantly carrying around the battery itself.
With a full charge, I have my Samsung S4 mini 2 times can completely load, then the Power bank was then but also completely empty. Charging per se has lasted just as well as at the outlet, so I was surprised here really positive. As a small gimmick, the Power Bank has also a built-in flashlight. One has to just the on / off switch and hold for about 3 seconds and you're on this or indeed from. The lamp is not terribly bright, for finding the handbag but it is very helpful. ;)