As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CABIN EMERG LIGHT: AT CRUISE THE EMER LIGHTS STARTER FLASHING WITH THE SWITCH IN THE ARM POSITION. REMOVED INOP #1 EMERGENCY BATTERY PN 7450LS-00 SN 006774 INSTALLED CUSTOMER SUPPLIED MODIFIED EBS FINAL ASSY PN 7450LS-00 SN 001730M CHARGED BATTERY FOR 90 MINS PERFORMED OPS CHECK OPS CHECK GOOD NO DEFECTS NOTED AT THIS POINT. RESTORED ALL ACCESS. ALL WORK DONE IN REF EMB505 AMM 33-52-01