Calculation with the ladle and approximating a lot of things, but giving an order of magnitude.

4000 mAh for Lithium Ion at 3.7V ->15 W.h

15 W.h charged at 200 Watt = 0,075 hour or 5 minutes.

Glad to know they are looking into this tech at the expense of 20% battery life in 2 years.

See also  Google and Facebook plan new undersea internet cable in Asia-Pacific