The battery of the WakaWaka Power+ has a capacity of 3000 mAh (P02A1GBxxx) or the order model 2200 mAh (WWP..), this means that devices with a smaller (or equally sized) battery capacity can be fully charged with the Power+. Some high-tech phones have a capacity beyond 3000 or 2200 mAh. A Power+ can charge these phones, but not fully at once. If you would like to know whether your device can be fully charged with the WakaWaka Power+, just take a look at the battery capacity (mAh) of your device.
Furthermore, it is important to note that your device will charge from a WakaWaka at approximately the same speed as from its grid charger.