What was found
AIRCRAFT WAS NOT GROUNDED: DURING PS CHECK FOUND EMERGENCY POWER SUPPLY UNIT BATTERY FAULT FIN 13WL, 16WL, AND 17WL. REMOVED AND REPLACED EMERGENCY POWER SUPPLY UNIT BATTERY FIN 13WL (AALA202110196281), 16WL (AALA202110198671), 17WL PER AMM 33-51-38.