What was found
FOR FLIGHT 3457 MAINTENANCE REPORTED, ARRIVING AT THE AIRCRAFT FOUND BATTERIES NR 1 AND NR 2 ON AUTO. THE GROUND POWER UNIT WAS AVAILABLE BUT NOT SELECTED. A STRONG "ACRID" ODOR WAS PRESENT. SHEDS OVRD, EMERGENCY LIGHTS ARMED AND ILLUMINATED FUEL PUMPS ON, APU SWITCH ON WITH THE AUXILIARY POWER UNIT NOT RUNNING SBY ATT UN-CAGGED, S/B SIGN ON. THE BATTERIES APPEARED TO BE DEAD. THE AIRCRAFT WAS REMOVED FROM SERVICE. REMOVED & REPLACED THE NR 1 & NR 2 BATTERIES IAW EMB-145 WORK CARD 24-600-00. THE OPERATIONAL CHECK WAS OK AS PER AMM 24-36-00. THE AIRCRAFT WAS RETURNED TO SERVICE.