A B757-200 WAS DISPATCHED IN NON COMPLIANCE WITH THE INCORRECT APU BATTERY INSTALLED.

Narrative

AFTER CLRING THE DEFERRALS FOR THE APU BATTERY CHARGER USING THE APPROPRIATE FAULT ISOLATION MANUAL REF; I WAS INSTRUCTED BY MY SUPVR AND MAINT CTL TO PROCEED WITH A BATTERY CHANGE WHICH I ARGUED AS BEING UNNECESSARY; BEING THAT THE BATTERY CHARGER I HAD INSTALLED HAD FIXED THE PROB AND THE ACFT WAS SCHEDULED TO DEPART IN APPROX 1 HR. THE LEAD MAN HAD PICKED THE PARTS AND WHEN THEY WERE BROUGHT DOWN BY THE STORE'S PERSONNEL; THEY ACCIDENTALLY BROUGHT THE WRONG BATTERY; AND WE WERE UNAWARE OF THE MISTAKE. THE BATTERIES LOOKED THE SAME AND ALL HOOK-UPS AND MOUNTING BOLTS MATCHED; THE PART NUMBERS WERE NOT EASILY IDENTIFIABLE. THE LEAD MAN WAS HELPING ME BY FILLING OUT THE PAPERWORK AND I THOUGHT HE WAS CHKING THE PARTS INFO TO MAKE SURE THE PART WAS GOOD. THE SUPVR DID NOT TAKE A PROACTIVE APCH AFTER BEING INFORMED OF THE PROB AND THE FACT THAT THE ACFT HAD JUST PUSHED BACK. HE DELAYED CALLING THE ACFT AND DID NOT INFORM THEM OF THE PENDING SIT. HE NEVER CONTACTED THE ACFT; AND THE ACFT DEPARTED.