A driver for a lighting device includes: a lighting driver configured to drive LED(s) of the lighting device in a first mode of operation when a primary power source is available and provided to the lighting driver and to control power output and/or final output current utilizing a backup or other secondary power source during an emergency mode of operation. In example embodiments and implementations, the lighting driver includes a single instance of a LED driver (e.g., only one LED driver circuit) configured to drive LED(s) of the lighting device during both modes of operation.