When Apple announced that it was going to continue selling the iPad 2 for $399 alongside its new tablet, the company never mentioned any changes. After all, it’s the same iPad 2 that it’s been selling for more than a year. Right?

Not exactly. The folks over at AnandTech uncovered a minor, but perhaps significant, change in the discounted tablet’s A5 processor that gives the slate nearly two hours of added battery life. Keep reading to find out how…

Apparently Apple traded in the iPad 2’s 45nm A5 processor for a much more power-efficient 32nm chipset. You may remember that Chipworks made a similar discovery in the third-generation Apple TV’s A5 processor last month.

So what does this mean? Well for folks with a “new” iPad 2, it means substantially longer battery life. AnandTech found that the 32nm A5 tablet could browse the web for an extra 1.6 hours, and could play games for an additional two.

But perhaps even more interesting are the implications. It’s certainly feasible that Apple will use a similar 32nm processor in the next iPhone — meaning greater battery performance. And with the handset rumored to include resource-draining features like LTE, and possibly a 4-inch display, that’s terrific news.

It’s also worth noting that, even with these new processors, Apple is still selling the iPad 2 at $399 (and Apple TV at $99). So essentially the company has found a way to manufacture the 32nm chips for the same price as the larger, less-efficient ones. That’s actually a pretty big deal.