I would download coconut battery and tell you but that app isn't ont he appstore anymore!
coconutBattery 4 - by coconut-flavour.com
With coconutBattery you are always aware of your current battery health. It shows you live information about the battery in your Mac and iOS devices (iPhone, iPad)
www.coconut-flavour.com
Really interesting to see the number of cycles, but it looks as though you actually take a lot of care about it, and yet it's at 82% and it's a year newer than mine, which is at 89%!I only charge it overnight if the battery percentage is below 40% when i go to sleep. Since I only sit at work and I can charge it there.
So I just charge it when it hits around 20% and stop it when it hits around 80%. It would get to 100% now and again if I get busy at work and forget to unplug or charge it overnight, perhaps once a week.