While some app says it’s bad for the battery, I have over 5 years of actual use proof. I have always charged my battery overnight. That means it’s on the charger for a minimum of 5-6 hours every night, and sometimes as much as 8 hours. I have always had good to great battery life on every iPhone I’ve ever owned.
Have you ever had your phone on the charger and it shows 100%, but as soon as you remove it from the charger, the meter drops to 97-98%? That’s because of the way the charging process works. When the battery charge reaches 100%, the charge process stops, and the battery may begin to lose charge. Once the charge level drops to around 95%, the charger starts the trickle charge until it reaches 100% again. Then the process repeats. This is to protect the battery from being overcharged.
Overcharging not an issue, VP says Apple's VP for recent controversy surrounding the way the third-gen device handles charging. The executive tells AllThingsD that an iPad does indeed report 100 percent charge before it's actually finished, but that overcharging is not an issue. Once an iPad genuinely hits the 100 percent mark, it will discharge slightly and then recharge, repeating the cycle until the charge cable is disconnected.
"That circuitry is designed so you can keep your device plugged in as long as you would like," says Tchao. "It's a great feature that's always been in iOS." He also insists that iPad users can always expect a 10 hour maximum, and that the behavior of the battery indicator was designed to avoid distracting or confusing people; a completely accurate battery monitor would show levels constantly rising and falling after a certain stage.
Read more: Apple's Michael Tchao clarifies iPad battery charging issue | Electronista Technically, what your app says may be true, but my experience tells me that it’s overkill and/or poppycock.