I have found an app called Normal which helps to find energy "hogs" and gives some actions needed. It collect details about running apps on the device, sends details to the developer's server (note --- no personal details) and returns the average usage on other subscriber's devices. It also warns if it is a hog app and gives some actions one might take to normalise things. Costs UK £0.99, but it is a help. I have no contact with the developers but here is the link in the app store. Normal: Battery Analytics by Kuro Labs https://itunes.apple.com/gb/app/normal-battery-analytics/id886528617?mt=8 Try it out and post comments.