The new iPad‘s battery performs within the normal parameters of an iOS-based device, thank you very much. At least that’s the story Apple is telling in the face of criticism of the way the company’s latest tablet deals with battery charging.
When the tablet reaches a nearly 100 percent charged state, the new iPad displays the battery as being fully charged, Apple’s Michael Tchao told the tech site. When that happens, the battery actually continues to charge all the way to 100 percent—but if it remains plugged in, it decharges a little, then charges back up fully, then back down again, and so on until the user unplugs the tablet.
Tchao billed that process as a boon to new iPad owners.
“That circuitry is designed so you can keep your device plugged in as long as you would like,” he told All Things D said. “It’s a great feature that’s always been in iOS.”
Apparently, Apple has been doing the same thing to manage the battery charging of several iOS-based devices, including iPhones, iPod Touches, and iPads, for several product generations. It just hadn’t gone noticed by many folks until a DisplayMate analyst grokked that his new iPad wasn’t fully charged even though the display indicated that it was, according to All Things D.
So basically, plugged-in iOS devices cycle between a completely charged state and a slightly decharged state, but Apple doesn’t reflect this in the Toshiba Satellite pro a120 battery status on its devices because it could “distract or confuse users,” according to Tchao.
DisplayMate’s Ray Soneira may have noticed the discrepancy between his new iPad’s actual battery charge and what the display was telling him it was, because the device takes a lot longer to power up its much bigger battery when plugged in than its predecessor, the iPad 2.
As PCMag lead mobile analyst Sascha Segan noted last week, “the new iPad appears to charge very slowly,” even though it’s actually charging just as fast as the iPad 2—naturally, because it uses the same power adapter. But as Segan points out:
The iPad’s 42.5 watt-hour battery is unusually large for a tablet. It’s more like a laptop battery. Both the 11-inch MacBook Air and Asus‘s Zenbook UX21 have 35 watt-hour laptop batteries. The previous iPad and the Asus Transformer Prime, the two major competing tablets, both have 25 watt-hour batteries.
But the new iPad comes with the same power adapter as the previous model, putting out 10 watts of power. That’s much less than the standard MacBook Air power adapter, which puts out 45 watts to charge a smaller battery.
The result is that the new iPad appears to charge very slowly. It’s charging just as fast as the previous iPad (it uses the same power adapter, Toshiba Satellite L300 Laptop AC Adapter), but it’s filling a bucket almost twice as big with the same trickle of water.
What that could mean is that the amount of battery charge that a plugged in, fully charged new iPad decharges itself by per its design would be quite a bit more noticeable to users than with earlier iPads (and iPhones and iPod Touches), because the amount of time it takes to cycle back to a fully charged state is just that much longer.
Of course, Apple has been taking some flak related to the new iPad’s battery life that extends beyond just the way the third-generation tablet charges up. As Segan also noted last week, the new iPad’s promised battery life of ten hours (actually ten hours, 54 minutes in PCMag testing) is possible—if you cut the screen brightness to 50 percent. At full brightness, the new iPad’s glorious and pixel-loaded Retina display burns through the tablet’s extra-large battery twice as fast.