The tooltip reads 3m duration, 3m cooldown, expires after 9 seconds of being out of combat.

It rarely lasts the full 3 minutes if you maintain combat, writ of lightning half the time or better seems to only apply tier 1 not the max tier, yet to see the 5s slow actually work for SW, EC bleed does not get applied even when EC is not resisted. This doesn't happen all of the time of course but it does happen a lot. Who cares about Sustaining Bolt returning power...have not had a need for that since you changed fate may as well just remove that from the tool tip.