Battery charged all night on trickle charger. Put it in after church and it cranked 1st time. Turned it off and tried cranking it again. Would not crank. Got the same "thump". Tapped on motor and not starter and it cranked right up. Let it run a few minutes. Cut it off and tried it again. No crank just thump. Tapped on starter and it cranked right up.
What now?