For capacity:
I own a Samsung Galaxy S3
To me to take a picture How long does the battery External I once the time until the 5000mAh no longer wants (ie empty).
My phone whines at 15% so I started there to load:
From 15% to 100% exactly 2 hours have passed with occasional eye on the clock and enabled WLAN. (Only 2 of 4 indicator lights on External Battery).
Next charging starts at 10%:
From 10% to 100% 2 hours 15 minutes passed also look with random at the clock and enabled WLAN. (Only 1 of 4 indicator lights).
And a final charge of 50% started:
50% was then loaded on 73% to the Power Bank was finally empty.
I hope I could possibly give a good idea how long and how much the Power Bank is making something.
Ps:
A feature I discovered by chance is when connecting to load his phone starts charging ... you want to interrupt you, for some reason, the charge does not have to be every time to pull the plug but hold only the control knob for mehrerre seconds. (Maybe it helps someone)