Wireless charging claims

I am fine with non-EE-background VCs clamoring over yet another startup claiming to charge iPhones over the air with whatever fancy technology whether it's scalable or not. The pain point is obvious and the use case is clear. 

However, at least keep a basic rule in mind:

  • A smartphone typically charges at a speed between 3W to 10W.

To claim that a wireless charging could charge a smartphone at the same speed as a Lightning cable or USB cable, it has to deliver this amount of power SUCCESSFULLY at the receiver end. It's therefore a very simple question to ask when you first meet a wireless charging startup:

  • What's your transmitting power?

If it's not in the range of Watts or tens of Watts, you could forget about the claim of charging "at the same speed as cables".

Bitcoin = Millennials' gold?

My investment watch list in 2018