updated 03:50 pm EDT, Tue March 27, 2012
Overcharging not an issue, VP says
Apple's VP for iPad product marketing, Michael Tchao, has responded to 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. "Itís a great feature thatís 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.
A analyst with the Yankee Group, Carl Howe, comments that it's actually common for many devices to report something below full as 100 percent. "That [full] might have been the case with older batteries, but todayís batteries have microprocessors managing their charging. So 100 percent is whatever that microprocessor says it is -- itís not any absolute measurement of ion concentration or anything."
He adds, "We donít have to understand their engineering to use them. However, we shouldnít apply our prejudices formed (both good and bad) from older generations of battery technology to todayís systems either. If it says itís charged, consumers should assume it is, and not worry about whether the charger is drawing current."