I don't really run my phone hard very often if ever. I noticed today for the 2nd time when my son was playing games on my phone. After 30 minutes or so when he was done and I looked at my battery the phone's internal battery would be below 80% say 76% or so. I keep it on efficiency mode at 80%. Has anyone noticed when using your phone hard the battery mod not being able to keep the internal battery at 80%. I'm using a Mophie.