what is the speed on Mercury 60 hp?

[lenarw79]

I have pontoon boat 20' with Mercury 60 hp engine and not getting full power. Last time if I Was boating it was like battery gone. I started engine ( jump start ) and boating maybe 3 min and engine shut off. I did this few times and I leave boat in marina. Is it like no charging battery or what . I have one more question, my max speed was 11-14 mph if I gave full power.