A Line Captain reports inadequate maintenance trouble shooting of an A320 'ADIRU on Battery' indicator light being inoperative and subsequent sign-off and the improper maintenance release that was issued. Adding to his concerns was the noticeable 'pilot pushing' to take unacceptable aircraft and 'mechanic pushing' to release aircraft or defer items.

Narrative

We submitted a report detailing that the nose light 'ADIRU on BATT' indicator was inoperative. Maintenance came out and claimed that this indicator was operating normally and released the A320 with a new maintenance release. We departed uneventfully. Upon arrival; we found that the nose light 'ADIRU on BATT' indicator was in fact still inoperative which would mean that the maintenance release was not a valid release. I have seen that Line Maintenance is being pushed to release and or defer items in order to get on-time departures and reduce delays blamed on maintenance; similar to the problem we have on the Operations side with Flight Managers pushing pilots to take unacceptable and or unsafe aircraft. We trusted that the write-up was cleared properly. I don't have an FAA Airframe and Powerplant (A/P) license; nor am I trained to know for sure that a write-up was properly cleared. It is unacceptable for [our] air carrier management to place a pilot; passenger and or equipment in jeopardy just for on-time departures. This is a small incident; however it must be noted for those concerned; that larger and higher safety related items are [also] being treated the same way; to pacify managements' desire for [financial incentives] associated with the on-time departures and arrivals.