The problem with increaseing the processor or the graphics processing capability of the Tablets is a the battery life. The whole point of having a tablet and its comfort is in holding it while not requiring to plug in a charger while using it. Drop the battery life anything less than 8 hours and Tablets loose their charm.
When Apple double the graphics capability of the 2012 iPad and doubles the DDR3 memory, its power shots up by 3/4 th above that of the iPad. If Apple used the same battery that it used in the iPad 2, that battery life will drop to under 6 hours from 10 hours. It will be a bad PR and disastrous for Apple.
Apple finds a simpler solution. Just juice up the battery with more Ampere Hour. The newer iPad uses 42.5 Watt Hour battery in place of the 25 Watt Hour in the iPad 2.
Table : 2012 Ipad and iPad 2 Batteries
|Battery||2012 iPad||iPad 2|
| Battery Life
||42.5 Watt Hour||25 Watt Hour|
|Power consumption Assuming 10 Hour life||4.25 Watts||2.50 Watts|
How do we define Watt Hour – If a device is rated at 25 Watt Hour, it will last 25 Hours if it takes 1 Watt of Power. If it takes 2 Watts of power, it will last 12.5 Hours.
Apple says that the newer iPad will last the same time as the iPAd 2 which will amount to 70% more power consumption. The larger battery comes at cost of two things – increased thickness and increased weight. Apple has been able to mitigate the increased thickness by using a slimmer PCB. The weight is not significantly more ( 652 grams Vs 601 gram) but then it is what it is.