After a day or two of this, I basically stopped worrying about the battery... until the cognitive dissonance set in. You see, the iPhone is designed to use all the available from an external power source before switching to its internal power. In this case, your phone will remain fully charged (or close to it) until the battery case dies. The lack of an on/off mechanism, though, means you can't have the case on and save power for later when your battery starts to dip into the danger zone. In practice, it doesn't matter -- you didn't have to worry about your phone's battery dipping at all for hours -- but I still felt powerless when faced with a dry battery and an iPhone on the verge of death. Technology sure is great at giving us new things to fret about. Then again, I've more or less been trained to think of battery cases like this; as things meant to help out in a pinch. I can't lie and say I'm already used to Apple's method, but I see why they did it. Maybe you won't have as much trouble adjusting.