We recently made an article dedicated to the battery of the new iPad, explaining how it was possible to maintain the same 10-hour performance, adding several new features such as Retina display, processor with graphics performance quad-core, support for LTE (4G) networks, 1GB of RAM, etc.
The new battery offers 70% higher performance than the iPad 2, going from 25Wh to 42.5Wh in milliampere-hours, from 6,944mAh to 11,666mAh. All of this occupies (practically?) The same space inside the tablet. There is only one problem with all this: the recharge time. According to MG Siegler, from TechCrunch, the new iPad takes many hours to recharge, saying that consumers are likely to do so overnight, the scenario is certainly worse when charging from a PC / Mac.
There's no way: you win here, you lose there.