Apple explains why your new iPad reads 100% battery before it’s finished charging

28 March, 2012 - Killian Bell
iPad battery status

There’s been a lot of talk surrounding the way in which Apple’s new iPad calculates its battery life since the tablet launched on March 16. It has been revealed that the device tells you its battery is at “100%” over an hour before it’s actually finished charging, and if you unplug it straight away, you could lose nearly 10% of its charge time.

So why does the device act in this manner? Well, it’s actually a feature built into iOS that allows you to continue charging your device for as long as you wish without damaging it. Apple vice president Michael Tchao explained to AllThingsD:

“So, here’s how things work: Apple does in fact display the iPad (and iPhone and iPod Touch) as 100 percent charged just before a device reaches a completely charged state. At that point, it will continue charging to 100 percent, then discharge a bit and charge back up to 100 percent, repeating that process until the device is unplugged.”

“That circuitry is designed so you can keep your device plugged in as long as you would like,” Tchao said. “It’s a great feature that’s always been in iOS.”

Tchao insists that even if you unplug your device the moment it reaches 100%, you’ll still get the 10-hour battery life that Apple promises in its advertising for the new device. He says that the reason your iPad continues to display 100% throughout the cycle is so that users do not think their battery is faulty and not charging properly.

Tchao also confirmed that this is a feature that’s present in all iOS devices, including previous generation iPads, and the iPhone and iPod touch. The only reasons it’s just come to light now is that the new iPad’s battery is so big, the time it takes to reach that “completely charged state” after displaying “100%” is much longer.

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About the author

Killian Bell is a freelance journalist based in Worcestershire UK. In addition to writing about all things Apple, he's one of the co-founders of the football site TitleTalk. You can follow him on and Twitter.