The top orange LED gives information about the device's battery level and charging state. When charging (plugged in), the LED will blink until the battery is fully charged (it will then turn solid which means the battery has more than 70% charged). When the Device is connected to the Shirt, the battery level of the device can also be viewed with the Hexoskin App under “Device Status”. When plugged into your Hexoskin Shirt, the top orange LED will display as follow: