iPad Charging Tip: Only user iPad Supplied 10W Charging Adapter.
I had issues while charing my new 64GB wi-fi iPad via USB, as numerous other users have as per many blogs/ forums. As I already have iphone3G, I have used the Charging tips from following link on Apple's site.
As I was not sure if I can use iPhone’s USB Adapter/ Wall Charger (bought from Apple store).
I have Apple iPhone Power Adapter / USB Wall Charger. iPad was charging via USB when it sync with iTunes on Macbook Pro. But when not synching, it doesn’t charge via USB always. Apple says, it is because of low power on USB 2.0 because of high power demand for iPad battery for charging.
Well on first 20 minutes it worked fine and charged my iPad upto 50% charge from 10%. Then it just blown / Fried my Adapter with big Spark & Sound.
On the same multi point power charger, I had other mobile charging as well as my Mac book Pro, Nothing happened to those and those kept charging as usual.
NO Power surge at that time, as the Multi charger have surge protector and that didn’t affect other chargers or charging devices.
However it fried my Apple iPhone wall charger/USB Power adapter. I have also posted in Apple Forum.
I Think, It exceeded the max rated wattage capability of the Iphone power adapter, which is only rated at 5V 1amp, so max ~5watts. It appears in this case the ipad hasn't regulated the power its drawing from the power supply and burned it out it should drop down to a 5V draw.
So according to Apple Tips this statement is misleading " 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."