weak/slow start after driving

Happened on Easter, took the demon out, started and ran fine, shut it down after about a 45min cruise, temp only got to about 170. had to restart after less than a minute after i parked it and it had a very weak/slow start like the battery was almost dead. did a quick visual, checked a few connections. tried starting it after it sat for a while and fired right up. checked the battery voltage and its at 13.7.

i heard about starters getting heat soaked, is this a possibility? what else should i look at?