A look at the different ways to charge your iPad and which is the fastest has been posted by Gizmodo.
The site examined the four most common ways to charge the device: The iPad’s standard 10W charger, Griffin’s PowerBlock iPad charger, the iPhone’s standard power adapter, and a MacBook Pro’s USB port.
They timed how long it took to do a quick charge (80%) since the last 20% goes very slow to preserve battery life.
The Griffin PowerBlock performed fastest, charging the iPad to 80% in 2.5 hours. The iPad charger came in second at 3.18 hours. It was followed by the iPhone charger at 5.5 hours and the MacBook Pro USB charge at 7.63 hours.