It is terrible that a third party software company can make money off of a need to diagnose poor quality in Apple product components. Yes, I am bitching.
Eight month old iPhone 5 still on iOS 6.x and it is so erratic in how the battery drops in percentage on Apple's own battery meter to be unreliable. Battery usage will always come on strong usage, and depletion, during use in congested areas, and least when not being used during off-peak hours.
Mine just dropped overnight from 58% to 13%. Yesterday morning ended a 24-hour charge, followed by time out of my home, including some mild non-video surfing, GPS, and iMessage.
I got home last night and the battery meter reported 70%. By the time I got o bed at 11PM it was 58%. This morning at 6AM it is 13%, which forced me to plug it back in. I'm in the suburbs with plenty of in-home wifi available, including in my bedroom.
How does a phone lose 45%, nearly half, of its charge in 7 hours doing NOTHING? Rhetorical question, but this is my first and last Apple cell phone.