Got a tip for us? Share it...

New in OS X: Get MacRumors Push Notifications on your Mac

Resubscribe Now Close

Apple Explains New iPad's Continued Charging Beyond 100% Battery Level

Among the many topics related to charging, battery, and heat issues with the new iPad, observers have noted that the device continues to charge for up to an hour after the point at which the iPad reports a charge level of 100%.

AllThingsD has now spoken with Apple's Michael Tchao about the phenomenon, with Tchao noting that it is simply an effect of the same trickle charging feature that has always been included in iOS devices.
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.

Doing so allows devices to maintain an optimum charge, Apple VP Michael Tchao told AllThingsD today.

“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 notes that users can expect 10-hour battery life on the new iPad regardless of when in that trickle charge/discharge cycle they unplug their device, and that Apple intentionally displays the battery level at 100% throughout that cycle so as to not confuse consumers who might otherwise think their device is not completing charging correctly.

Related roundup: iPad Air

Top Rated Comments

(View all)

32 months ago
There. Death to 'batterygate'.
Rating: 82 Votes
32 months ago
This makes sense. People need to stop freaking out.

Li-Ion batteries don't fare well when they are held at a 100% charged state (or 0% for that matter) for extended periods of time. By allowing the battery to charge and drain a small amount continuously while plugged in, the life of the battery is extended significantly.

Basically, Apple is setting "100%" to be less than the actual capacity of the battery (and has defined 100% as the "rated" battery life) -- so you could actually see better results when your battery is actually charged "beyond" 100%.
Rating: 67 Votes
32 months ago

This is unacceptable.

What a monumentally useful comment! *claps and applauses*!
Rating: 63 Votes
32 months ago
Please let this stupidity go away now....please?
Rating: 55 Votes
32 months ago
So this seems to be official confirmation that keeping iOS devices plugged in all the time doesn't hurt long term battery life... This has been hotly debated for years!
Rating: 54 Votes
32 months ago

Of course, "it's a feature"

Yes - it is.
Rating: 40 Votes
32 months ago

I always wondered why sometimes on my iphone and ipad it would take to take forever to come off of 100%. Other times it was pretty quickly.
Rating: 25 Votes
32 months ago
As they mention, it has always been like this. I've noticed this myself with previous iPads and iPhones. Charge will be at 100% and I'll use it for 10+ minutes and it still lists at 100%. Other times it drops to 99% after a minute or so.
Rating: 17 Votes
32 months ago

Well, then they should have pegged it at 99% until it truly reaches 100%.

Step 1: re-read the article
Step 2: ask an engineer friend what the article means, or do your own research.
Step 3: questions ? goto Step 1 : exit( ok )
Rating: 16 Votes
32 months ago
This makes total sense. Thanks!
Rating: 14 Votes

[ Read All Comments ]