Indication  | LED  | Description  | 
|---|---|---|
Solid amber  | Spare battery is charging.  | |
Solid amber with alternate bright amber  | Best spare battery is charging. Not available on 2-Slot USB/Ethernet Cradle.  | |
Solid green  | Spare battery charging is complete.  | |
Solid green with alternate bright green  | Best spare battery charging is complete. Not available on 2-Slot USB/Ethernet Cradle.  | |
Solid red  | One of the following:
                 
  | |
Fast blinking red (2 blinks/second)  | Error in charging; check placement of spare battery. The battery is at the end of useful life.  | |
Off  | One of the following:
                 
  |