I have a Mercury 50 hp ELPT 4 strokes , s/n 1C084939 Set 2008, recently change out the battery.
I hooked battery leads up to reverse poles.
I blew two fuses , the 15 Amps fuse (Main Relay/Accesories) and 25 Amps fuse (Main circuit). I replaced both , and correct the battery leads connection...