My ipad draws over 2a, and the iphone at least 1.5 depending on how hungry it is. I have swapped all my 12v USB to a dual 2.1 EACH OUT device. It does what it says and I dont have to play the Right Stuff current game with it trying to keep a regulator from crowbarring.
For the 115v stuff I have dual 2.4A EACH OUT made by iClever that run close to cold loaded with dead Apple devices. One of those replaces a certified Apple charger that overheated and melted the carpet.
Bought a 12000ma pack off ebay that I use in the air but havent looked at how much I can shove into it yet. I can run the ipad all the way across the country.