iPhone battery life is not great especially if you do a lot of stuff on your phone. When it's plugged in charging, the iPhone is not in my pocket. I'm usually all over the place during the day. My phone is charging at my desk, but I'm not there and miss stuff. I also have small charger that's about the size of my thumb. But this requires a wire to be attached between the phone the charger. It's real clunkly. It doesn't all fit in one handle easily. It would be nice to have a phone that can last for a few days or be able to swap batteries on the fly. But this is not the case with iPhones. Plus you have to remember to charge it each night.
Do you know how to shut down apps on your iPhone? (insert curse about apple not having shit for manuals here)
Double tap the home button and swipe up on all the stuff that appears. If you shut things down, the battery lasts much longer.