[mikeash]

Doubling is an underestimate. It's more like a factor of 10.

Still, multiplying the cost of charging an iPhone by 10 isn't bad. And in fact you can buy a lot of solutions that enable this, because you're right, it's not a big deal for a lot of people, and the convenience is worth the cost.

For an electric car, increasing the charging cost by a factor of 10, or even a factor of 2, is a much tougher proposition.

[seanflyon]

Where do you get a factor of 10 from?

[mikeash]

From my butt, apparently. I was sure that was right, but checking into it now, and it looks like it's more like 60-85% efficient.