When the keyboard is plugged in and the red light stays on, this means the keyboard is still charging. Within a few hours, you will notice that light has shut off. This indicates your Brydge is fully charged at 100%.
Please note that the charge life is primarily influenced on how often you are using the backlight keys. If your backlight keys are always on, the battery will drain significantly faster.
To check the battery life manually, press and hold the 'Battery' key until you see a light flash on the power key.
Green = 100-75%
Yellow = 75-25%
Red = <25%