Just how practical is solar power for keeping your smartphone going?
(All About Windows Phone)

It`s an idea that I`ve toyed with over the years, and prompted by a recent submission for review of a solar-powered smartphone power bank (link below, it had a design flaw!) Now, I`m in the UK and the sun isn`t exactly a reliable resource, but hey, picking a sunny day or two in early Spring here, I applied some science to the solar idea. Using my trusty Choetech 19W tri-fold panel, I`ve been taking measurements and doing some maths...