Mechanic reports he replaced a B767-400 main battery using the part number included on their open maintenance list of routine work they were given. During flight; a Maintenance Coordinator noticed the part number and battery were not effective for that aircraft.

Narrative

While performing scheduled maintenance on a B767-400; the work package open maintenance list included replacing the main aircraft battery per a routine job card. The Maintenance list also included carrier part number for the battery. The Lead Mechanic ordered the battery using the company part number on the maintenance list. Myself and one other Aviation Maintenance Technician (AMT) replaced the aircraft battery. I signed off operation and the logbook entry; after confirming part number from the maintenance list was same as part number installed. While completing paperwork in cockpit made mental note to confirm part number in illustrative parts catalog (IPC). I then got distracted due to other work going on and forgot to thoroughly confirm proper battery part number. I was told aircraft made flight and during flight part number discrepancy was found by Maintenance Coordinator and corrective action was taken before next flight. Changes that could be made to prevent problem:1. Open maintenance list should not have part numbers on it unless those drawing up the maintenance list are held accountable for the accuracy of the information they put in it.2. B767-400 IPC should be cleaned up; with battery part number; effectivity and such; to be more clearly reader friendly.3. Multi-tasking should not be encouraged by lead mechanics.