It’s a constant iPad issue. You can plug in your iPad via USB to your computer, but it will just sync to iTunes. There is no charging going on. The only way you can charge it is through the Power adapter it came with that you need to plug into the wall. This mostly is a PC issue, but may occur also on old Macs. Why?
If you have an older computer, or one that doesn’t have a high-speed USB port, you won’t be able to charge from it. Plain and simple. So, your USB port just doesn’t have enough power to charge your iPad. As your resident NYC iPad service guru, I have simple and affordable iPad fix here for you.
For only $5, you can buy a USB Adapter that turns your slow USB port into a faster one that can charge up your iPad. There are a few options out there, but the ones I like are the iXP1-500 and the Mertiline USB Charging Adapter. Depending on the model and your computer, you may only have the choice to charge or sync, and not both simultaneously. Hey, what do you want for $5!
The USB adapter is great if you’re going on a business trip with your iPad and laptop and want to consolidate your tech support cables.