One thing that Apple didn’t talk about when they announced the new iPad earlier this week was just how insane of a battery it has inside. The iPad 2 has a 6,944 mAh battery and goes for about 10 hours. The new iPad has a 11,666 mAh battery, which is roughly 70% larger, yet still only gives you 10 hours of juice. How can that be? Something tells us that the retina display and the 4G LTE have a lot to do with the decision to use a battery that’s larger than what’s inside the latest generation 11 inch MacBook Air. This brings up a serious question though: If the new iPad needs 70% more juice to last the same amount of time as the old iPad, then what’s going to happen to the next generation iPhone? When the iPhone 4 came out in the summer of 2010 it had the best screen on the market. Some might argue it still does. This year however we’re going to see 1280 x 720 pixel screens dominate the Android scene, some using LCD technology, others using AMOLED. If Apple decides to compete with that by using an even more pixel dense display, then that’ll mean the new iPhone will also need a new, possibly much larger, battery.
Using the information we have available, Apple says the 3.5 inch iPhone 4 is considered “retina” because it has a PPI of 326. If Apple were to increase the screen size of the iPhone to say … 4.3 inches, what resolution would it have to have to keep the same PPI? If you multiply the vertical and horizontal resolution of the current iPhone by 1.25 you get a new resolution of 1200 x 800, coincidentally the same resolution as the Samsung Galaxy Note. If a display had that resolution and measured 4.3 inches diagonal it would have a DPI of 335. That’s not only better than the 326 DPI of the iPhone 4/4S, but you could also put a massive battery inside a device with that kind of footprint.