User blog comment:Linathan/Squad Spotlight: The History of Linathan - Chapter 1/@comment-24277289-20150715013830/@comment-26140304-20150716015050

Key, I remember it was 10 minutes per energy. It wasn't until around October 2014 when Gumi decided to implement 3 minutes per energy. I think you might be thinking of Chain Chronicle's energy refill rate. :/