To preserve the battery life of your iPhone, Structure Sensor has its own internal battery. Charging your Structure Sensor's battery is simple:
Connect the supplied Power Adapter to the barrel jack (the round port on the side of Structure Sensor), and then plug the other end into a wall outlet (if you are outside of the US or Canada, you will need to use an appropriate adapter).
An LED indicator on the Structure Sensor's glass face will pulse when your Structure Sensor's battery is charging.
As soon as your battery is completely charged, the LED indicator will stop pulsing and instead will remain solidly lit until you disconnect the Power Adapter.
Structure Sensor can operate for up to 4 hours of continuous usage with a single charge.