Since submitting the article the official power supply came out at MCM/Element14. It works with the Pi 2 and Pi 3 and comes with travel adapters, all for under $10, so there's really no reason to buy anything else. Only one out of ten USB cables I tested could actually handle 2 AMPs so it's nice to have a wire rated for 2.5A supplying the juice (no more flickering red light) even if you don't need all that power. Tzumi also now has a 2.4 AMP USB battery. If 2.1A is "turbo charging" then I guess this one is "super charging".. or something like that... George Orwell was an optimist.