A longer sampling period could certainly be a potential solution. It could also cause a different sort of user confusion. If I start up a game, play for a few m

A longer sampling period could certainly be a potential solution. It could also cause a different sort of user confusion. If I start up a game, play for a few minutes and then worry about battery life and go check.. If I still see 8 hours I'm seeing the wrong info and may make a decision to keep playing that I will regret in two hours. I still think something like the battery over time graph is a better solution than a single number with so many assumptions built in that are opaque to the end user. The graph can express "you've not been using a lot of power but whatever you started recently has caused it to drop a lot faster."