The iPad 3 is reported to draw more current than the earlier models, but has a higher capacity battery to compensate. You should use about ten percent of your battery capacity for each hour you use it.
If you are getting less than eight hours of battery life after a full charge, it may help to calibrate the iPad's battery measurement function. Use the iPad until it quits. Then charge it for several hours using its wall charger, until it indicates 100%.
With short battery charge life after calibrating it, your iPad may be defective.
I had the charge complete down to ZERO yesterday (discharged the battery completely) since it seems not to hold the charge as I stated.
Then I did a hard restart with a 1% charge.
Then I let it charge all night.
It finally reads 100% for the first time since I bought it, so maybe it was needing to be stretched (the battery) to ghe full capacity as you state.
I will drain it down one more time and report if we are holding the charge.
Currently it seems I am drawing much less, but I want to go through a full cycle (back down to zero, hard restart, full charge) before reporting that I am satisfied.
The quickest way (and really the only way) to charge your iPad is with the included 10W USB Power Adapter. iPad will also charge, although more slowly, when attached to a computer with a high-power USB port (many recent Mac computers) or with an iPhone Power Adapter (5W). When attached to a computer via a standard USB port (most PCs or older Mac computers) iPad will charge very slowly (but iPad indicates not charging). Make sure your computer is on while charging iPad via USB. If iPad is connected to a computer that’s turned off or is in sleep or standby mode, the iPad battery will continue to drain.
Apple recommends that once a month you let the iPad fully discharge & then recharge to 100%.
At this link http://www.tomshardware.com/reviews/galaxy-tab-android-tablet,3014-11.html , tests show that the iPad 2 battery (25 watt-hours) will charge to 90% in 3 hours 1 minute. It will charge to 100% in 4 hours 2 minutes. The new iPad has a larger capacity battery (42 watt-hours), so using the 10W charger will obviously take longer. If you are using your iPad while charging, it will take even longer. It's best to turn your new iPad OFF and charge over night. Also look at The iPad's charging challenge explained http://www.macworld.com/article/1150356/ipadcharging.html
Also, if you have a 3rd generation iPad, look at
Apple: iPad Battery Nothing to Get Charged Up About
Apple Explains New iPad's Continued Charging Beyond 100% Battery Level
New iPad Takes Much Longer to Charge Than iPad 2
Prolong battery lifespan for iPad / iPad 2 / iPad 3: charging tips