Try this first - Reset the iPad by holding down on the Sleep and Home buttons at the same time for about 10-15 seconds until the Apple Logo appears - ignore the red slider - let go of the buttons. (This is equivalent to rebooting your computer.)
The quickest way (and really the only way) to charge your iPad is with the included 10W or 12W (5W on Mini) 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 (2.5W, 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%.
How to Calibrate Your Mac, iPhone, or iPad Battery
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
Apple Batteries - iPad http://www.apple.com/batteries/ipad.html
iPhone: Hardware troubleshooting (Power/Battery section also applies to iPad)
Extend iPad Battery Life (Look at pjl123 comment)
New iPad Slow to Recharge, Barely Charges During Use
iPad: Charging the battery
Best Practices for iPad Battery Charging
Tips About Charging for New iPad 3
How to Save and Prolong the battery life of your new ipad
Prolong battery lifespan for iPad / iPad 2 / iPad 3: charging tips
iPhone, iPod, Using the iPad Charger
Install and use Battery Doctor HD
To Extend a Device’s Battery Life, Get to Know It Better
iPad Battery Replacement
In rare instances when using the Camera Connection Kit, you may notice that iPad does not charge after using the Camera Connection Kit. Disconnecting and reconnecting the iPad from the charger will resolve this issue.
Cheers, Tom ￼
I have an iPad2 and recently updated to ios7.0.3 Then last night (I usually plug it into the mains charger overnight) when I plugged in there was no ‘bong’ noise indicating that charging had commenced. This morning it had not charged at all. I use a battery maintenance app and it showed that charging was not taking place. However I don’t think this was directly the result of 7.03 as I am convinced it charged correctly the night before with that ios.
As recommended by some of these comments I then tried connecting it via my camera cable to my computer. Although it actually displayed near the battery symbol (top right) that it was.’not charging’ I left it connected and after about 6 hours it had actually charged up from 20% to 50% according to my app. I then kept that camera cable connected to the ipad and replaced the one on the mains adaptor. The app indicated that there was no charging, and the level stayed more or less constant.
I have been adding new apps most days when they turn free from charge and wonder whether one of them has interfered with the ios7.0.3. Could that be a possibility? If it is not something like that, then I am perplexed as to why the non-charging did not immediately occur on installing 7.0.3.