When Apple showcased their iPad in January they never thought that their product iPad will sell so quickly. Since the launch was on 3rd April , it is quite early to comment on the device. Many users in US have started complaining about the charging status of their iPads with USB on certain Windows based PC’s and Old Macs. Is your iPad among the ones that is not being charged by the USB port of the computer ?
iPad not Charging when using USB Port of certain Windows PC and Old Macs
To be specific, let me explain the current USB Standards. Currently all of us are using USB 2.0 and some of the old PC’s are still on the old USB 1.1 interface. A unit load of current can be drawn from a USB Port in both USB 1.1 and 2.0 specifications. The specification mentions that a device can draw up to 5 unit loads of current from both USB 1.1 and 2.0 specifications and therefore a USB port in a PC or a laptop can supply 5V at power of 500mA.
The USB ports on Apple computers provide 5 V (Volts) and 500 mA (Milliamps) to each port, regardless of whether the port is USB 1.1 or USB 2.0. This is in compliance with USB specifications. On some newer Intel-based Macs, such as the MacBook (13-inch, Late 2007), when a device requiring more than 5V and 500mA is connected, the port with that device connected to it becomes a high-powered port capable of offering up to 1100 mA at 5 V. That port will continue to operate as a high-powered port until the device is removed.
If you are facing such a problem where your iPad does not get charged with USB port of your PC / Laptop or Mac then it is advised that you should use the provided 10W charger with the iPad which will eventually charge your iPad within stipulated time.
The fastest 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. When attached to a computer via a standard USB port (most PCs or older Mac computers) iPad will charge, but only when it’s in sleep mode. 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.