Overall, the battery bank makes a good processed and stabilized lien impression.
4 small blue LEDs indicate the charging status of the device. You blink even when the solar pannel is supplying power. The solar pannel se delivers 180 mAh with optimum solar radiation. It takes about 40 hours until the calculated empty Power Bank would charge. Realistically the solar pannel to support serves more so for direct charging. There is not big and powerful enough.
Nevertheless, the Power Bank is of good use and functional. Too bad that the device only has a USB output.