Adrenaline keeps flowing for how long?

Has anyone timed how long adrenal charges last when not active in combat? Just a wild guess from me, it felt like 15-20 secs maybe?

Also related, how much longer is it extended using the various Runes of Fury?

in my expierience it can last 10-25 seconds, depending on if you used a skill right before the fight ended, and im not sure about the rune question

If no one has the numbers yet, I'll test this in 2 weeks time.