The difference between 10w and 20w is the difference between charging power and charging speed, 20 watts of charging power is twice as big as 10 watts, charging 20 watts per hour, and the speed is twice as fast as 10. The number of turns of the transformer coil contained in the two chargers is different, and the power of the ipad charger 10w is 2w less than the power of 12w. Apple upgraded the 12w charger to charge 40 to 50 minutes faster than the 10w charger without affecting battery life and damage. The 10w charger is the charger of iPadmini1 and mini2, and the 12w charger is the charger of ipad series, and the two supply product models are different.