What does it mean that both Status and Charge LEDs are solid on?

Full featured emergencies have both a Status LED in addition to the Charge LED.

The Status and Charge LEDs are independent of each other.

The Status LED is always yellow and the Charge LED may be Red or Green.

A solid Yellow Status LED indicates that the device is in normal operation and no duration test is immediately pending.

A solid Red/Green Charge LED indicates that the device is functional, the charge is operational and no reported issues. 

Note: In some models the charge and status is combined into single LED where orange indicates that both charge and Status LEDs are illuminated.