1994 SAAB 900 Starting problem

My 94 2.3 SAAB 900s NG will not start. I switch the ignition on and the dash board lights up as normal, one click further to start the engine and all I get is click, click, click and the dash lights flashing. I have been out about a week, when I come back home and tried start, this happens. Battery read 12,5v. Anyone got any idea what the problem is?
Thanks