As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CABIN EMERG LIGHT: DURING PRE FLIGHT CHECK, NO EMERGENCY LIGHTS COME ON WITH MAIN BATTERIES OFF AND SWITCH IN ARM. LIGHTS WILL COME ON WITH MAIN BATTERIES OFF AND SWITCH IN ON POSITION. UPON START UP NOTED BATTERY VOLTAGE WAS LOW. ENERGIZED THE AIRCRAFT AND CHARGED THE SYSTEM. PERFORMED OPS CHECK. GOOD. IAW CE680A AMM 33-50-00