After a wipe, the electrified floors often remain electrified, and his shield and power stacks don’t get erased. Our party wiped and I watched his power stacks continue to rise while we were waypointing out. (no one is in combat when we waypoint). When we got back, his power stack was at 30.
So for the next round, we had to deal with his power attack and a panel of the floor electrified from the start. The timer to remove that stuff is 1 hour, which is unneccessary.