External battery fully functioning. A Led 4 spot indicates the load level for a few seconds when it is connected to a device, or stays on when it is plugged in while showing the progress of the load. Charging a unit is not as fast as a direct connection to industry, but the time difference is not huge. Moreover, this external battery is primarily used in troubleshooting. Its compact size "flattened tube" of 9x4x2 takes up little space in a bag or pocket. By cons, its weight is still 140g. Even if it is ridiculous, it can feel relatively in a pocket. Last advantage of this battery, it has 2 USB ports and can recharge two devices simultaneously. I tested, it has the ability! 2 USB cables of different lengths are provided but the battery works perfectly with my HTC cable or brand under cable. It is a no-fault for this battery.