IPhone 5s battery fluctuation?

Hi. My iPhone 5s is less than a year old. I take good care of it. Run it down to 3 percent and fully charge it. Every couple of weeks I fully run it down to shut off to recalibrate it. But sometimes if I move it outlet to outlet, when I plug it back in Otto jump from like 74 to 79 percent or 95 to 100. If I keep it plugged in extra long will it FULLY charge?

By the sounds of things, yes it will charge fully