PowerPack - Wireless Portable Charger
It depends on what phone you have and how large the battery is. The PowerPack will charge most smartphones 2-3 times from 0-100%.
The PowerPack has the ability to charge almost every smartphone on the market, and almost any device of your choosing. It has two built-in charging cables that allows for so much choice and freedom. It will also charge wirelessly any device that is Qi-enabled.