Ok, then your battery was installed correct. Once, I was installing a new battery and I made reverse contact for a split second (while I was setting up the new battery) and that killed my board.
Well, it's just a hunch: But, it seems like the current was interrupted, as mentioned above.
Unfortunately, after a CPS-2 game fails to start (suicides), installing a battery (even a second battery) will not put the start up codes back onto the board. Been there--Done that--Same results.
What the board really needs is to have the start-up codes re-flashed onto the board and a new battery put on the board.
But, since that repair option is only a CAPCOM fix, your next best option is either to revive (phoenix) the dead board or sell or trade the dead baord to someone who is looking for a CPS-2 parts board or a CAPCOM project.