The Amazon Kindle App for the iPhone and iPad has been a battery hog for the last month. Even when you aren’t reading an e-book and doing something else, the app remains in standby mode.
The Kindle app was updated April 15th 2015 with the quintessential “performance and stability improvements”. This last update was the culprit and many people are finding their tablets or smartphones are not lasting as long as they should. I have an iPhone 6 Plus and most of the time I get about a day and a half of usage. The Kindle app has relegated it to about 15 hours, before it runs out of juice.
I think the main problem is primarily due to a Whispersync timing issue. This is the Amazon system that fetches new content or books you purchased on other devices. There is no way to disable this with Background App Refresh, because Amazon does not have that feature on iOS 8.
Update: Amazon contacted me with the following statement “First, the Customer Service response referenced on ZDNet was incorrect, as this is not a problem we’ve seen customers experience broadly. In fact we’ve only had a handful of customer contacts related to battery usage on iOS since the app update on April 15th. Additionally, I want to clarify that the Kindle app does not register for permission to run and does not run in the background on iOS.
I also wanted to note that the Battery Usage screen reports the relative percentage of power used by each app for a period of time, even though the total battery consumption may be minimal – and only updates infrequently, not in real time.”