Charging at the outlet was about 2.5 hours. (You can also charge the battery in any USB Anschkuss charge)
A flashing LED indicates the charging process if it stops flashing, the battery is full. Well, the overvoltage protection, which means you can leave the battery safe long into the outlet.
With a single charge my Samsung could be S 4 mini fully charged and the larger battery Lenove my yoga Tabs was 2/3 full. Very decent value.
Easy to use, good performance: Actually 5 stars. 1 star deduction there because of the confusing size specification.