SparkFun 5V/1A LiPo Charger/Booster Hookup Guide
Connecting a Load
Eager to get your 5V? Just connect up to the output terminals!
But there's always more to know. An ideal booster circuit translates all input power to output power, so if the output is providing 5V @ 1A, or 5W, 5W must also be going into the booster. But if the input voltage is down to the battery lower limit of 3V, it will require 1.666A! With an efficiency of around 85%, it requires almost 2A on the input!
Here's a graph of the charger booster's measured performance: