It’s a well known fact that the new iPad takes significantly longer to charge than the iPad 2. You can chalk that problem up to the fact that the new iPad has approximately 70% more battery in the same form factor than the iPad 2, requiring almost twice as long to charge. Consequently, the iPad has gone from being something you could charge up in just a few hours to a tablet that needs all night to charge to 100%.
But you shouldn’t stop charging your iPad at 100%. No sirree bob. If you want the most battery life from your new iPad, you should keep the device plugged in for at least an hour after it reports full. Why? The iPad battery gauge lies.
Dr. Raymond Soneira of Displaymate Technologies (and the author of this fantastic iPad display review), wrote in to alert us to an interesting fact.
“I measured the power actually drawn by the AC adapter and found that the new iPad continues to charge for up to 1 hour after it claims to reach 100%,” says Dr. Soneira. “This affects the battery run time if you stop charging when it says 100%.”
The new iPad isn’t alone in this sort of battery charge fudging. Other devices apparently do this as well, according to Dr. Soneira. There’s often a disparity between how much electricity has been drawn from an outlet compared to how full a device thinks its battery is.
Either way, the solution is clear. “If getting maximum battery runtime out of your device is crucial, people need to keep recharging their new iPad for longer than iOS claims.” So if you’re charging your new iPad for eight hours every night, time to start charging it to 9 if you really want a full charge for the day ahead..