It's easy to check the charge status of the included battery that comes with the MediaTek LinkIt one!
MediaTek LinkIt One board and battery that comes with it
Micro USB Cable
Computer with MediaTek SDK installed
First connect the battery to the MediaTek LinkIT one but leave the USB/Battery power switch in the USB position.
Step 1: Upload Code
Under the example code find the LBattery folder and open that example code. Upload that code to the LinkItOne and open the serial monitor to 115200 baud rate.
Step 2: Serial
The serial monitor should then print out the charge status as well as if the battery is charging.