Posted by a reviewer on Amazon

Some reviewers disputed the published size of the battery based on what it could charge up but there are two problems there

Posted by a reviewer on Amazon

The first is that if you charge a phone while it is on you would have to provide enough power to charge the phone battery plus what the phone used while it was charging

Posted by a reviewer on Amazon

You cant simply connect the battery in this device directly to your phone battery you have to increase the voltage of the output which takes more current and there are also some efficiency losses in the process

Posted by a reviewer on Amazon

Bottom line if you have a 2000 mah battery in your phone do not expect this to fully charge it 4 times

Posted by a reviewer on Amazon

My only two complaints about it are that the usb output ports are on top next to wrist strap and there is no good way to put this on a backpack and keep the solar panel facing out

Posted by a reviewer on Amazon

It takes awhile for it to charge both for the powerbank to juice up and to charge my phone but for my s5 i can get like 22

Posted by a reviewer on Amazon

This product was given to me as a replacement for another product one that did not work