starting problems

ok so i blew my head gasket so i had to rip aprt the engine.i put everything back every thing is hopefully right.i connected everything and now wen i turn the all i hear is a click,wat can it be im hopin its myabe the battery,ima jump it n like 15mins,wat else can the problem be?the clicking is in the starter relay

nevermind,i kinda knew it was the battery,wat happened is that my pops turned them on to fill up my tanks to be able to lift it with the truck off,hes tryin to blame it on me sayin that my system killed the battery,i had it on for like 1/2hr with no bass and hes tryin to blmae it on me,i told him that it was him but he dont want to admit it,lol.