As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: DURING EMERGENCY LIGHT CHECK, FOUND "BATTERY FAULT" ON 10WL EMERGENCY POWER SUPPLY UNIT. REPLACED EMERGENCY POWER SUPPLY UNIT BATTERY (10WL) AND ACCOMPLISHED A SATISFACTORY OPERATIONAL CHECK PER AMM 33-51-38.