Crack open an iPad and you'll find a massive battery pack that makes up most of the tablet's heft. The 42.5-watt-hour rechargeable lithium-polymer battery in the 3rd-gen iPad is a big improvement over the iPad 2's 25-watt-hour battery. Both models offer up to 10 hours of usage between charges. (The newer model needs the larger battery to power its faster A5X processor, Retina display, and optional LTE wireless--and still hit Apple's 10-hour target.)
The Google Nexus 7 runs 9 to 10 hours on battery power, while the new 7-inch Amazon Kindle Fire HD promises up to 11 hours of use. Will the iPad Mini top them all? A best-of-breed battery would be strong selling point, particularly if Apple follows tradition and prices the Mini at a premium.