The iPad doesn't charge with USB connection to the computer?

Connect to wall outlet Uses the USB power adapter and USB cable included with the device. If it is a third-party accessory, check to see if it is Apple Certified . Then follow these steps:

1. Connect the iPhone, iPad or iPod touch to the Lightning to USB connector cable or the 30-pin to USB connector cable .
2. Connect it to one of three power sources:

Wall outlet

Connect the charging cable to a USB AC adapter and connect the USB AC adapter to the wall outlet.

Computer

Connect the charging cable to a USB 2.0 or 3.0 port on a computer that is not in sleep mode. Do not use the USB ports on the keyboard.

Power supply
Connect the cable to a powered USB hub, docking station, or other Apple-certified accessory.


When the device is charging, you will see a lightning bolt next to the battery icon in the status bar or a large battery icon on the lock screen.

Yes if you have a computer with a usb port, you can take your charging cord and plug the usb side into your computer and the other side into your iPad. This will connect the iPad to the computer.

Hello,

If you charge your iPad on a power adapter, the iPad should respond while charging, except if your iPad battery is so low the apps need more power to run.

If you charge your iPad on the USB port of your computer, it is normal you cannot use your apps as the iPad is not only in battery charging mode but also in synchronizing mode with iTunes in the computer. You should lose the habit to charge the iPad on the PC and use a dedicated power adapter instead, as dedicated power adapters charge the iPad battery 2 to 4 times faster than the USB port of most computers.
USB port power: 2.5 Watts in general (5 volt x 0.5 A = 2.5 Watts)
iPhone charger: 5 watts
iPad charger: 10 or 12 watts

As soon as you connect your iPad to a working charger, it will beep. If you plug in the cable and you don't hear the beep, assume something is wrong. Just find out what, the cable or the charger.
Don't try to charge the iPad with a computer, because the 500 mA a USB connector from a computer can give, is not enough even to start.
But you can use a computer to test the cable, because the iPad should beep and say on the screen not charging.
If there is no beep when connecting to a computer, you have to use another cable. If it beeps, buy a new charger. 5 Volt 2 A. The best an Apple charger.

First steps: Make sure you're up to date

1. Verify you have installed the latest version of iTunes.
2. Verify that you are connecting iPad to your computer using a USB 2.0 port.
3. Make sure your iPad software is up to date: With your iPad connected to your computer, click "Check for Update" in the Summary section of iTunes.
4. Charge your battery: Using the USB power adapter that came with iPad, charge iPad for at least 20 minutes before further troubleshooting. If necessary, refer to "Charging the Battery"

To charge an iPad you have to connect the USB cable to iPad power adapter (12W in power and is bigger in size compared to iPhone's). If you connect it to iPhone power adapter you might see that the iPad is not charging, but will take a very long time to charge. The same goes with connecting directly to computer.

Also, there is always a chance that either your cable, or adapter or the iPad itself has gone bad.

Turn it off when its off connect the cable that's used to charge it to a pc or laptop making sure ipad is still off hold the home button do not let go now keep it held down until you connect the cable and see a picture symbol showing to connect to iTunes as soon as you see that on the ipad you can let go off the home button if iTunes doesn,t open itself you do it it should now see an ipad in recovery mode click on restore or restore and update please note that this will erase your whole ipad back to factory settings

To get Ipad to show as charging download Asus AiCharger from web and restart computer after install.Plug in usb from Ipad and should now show charging http://event.asus.com/mb/2010/ai_charger/

USB hubs typically don't generate the 10 watts necessary to charge an iPad when it's connected to your computer. This basically means you can't use your laptop to recharge your iPad.

Apple recommends finding an AC outlet and using 10-watt power adapter that came with your iPad.

I request you to visit the below url for your query
http://support.apple.com/kb/TA44551