Solast week I got a discounted solar off-grid backpack from Voltaic and had a great opportunity to test it over the weekend as my BF and I went up to the Peak District for the wedding of a fellow ACCU friend.. This gave me the chance to both have a long walk AND to see what the charger could do.
I confess that at first I was not terribly impressed but I think that this is because I've never used a solar charger before AND because (I confess!) I hadn't read the instructions. OK, ok - mea culpa. Fortunately I did my usual "up with the sparrow's fart" routine and set the pack in the window to charge at dawn and so, a few hours later after an ample English Cooked Breakfast (BTW, props to the staff at The Waltzing Weasel for the hearty meal!) I returned to a fully charged battery pack which swiftly charged my iPhone.
It should be noted that the batter pack was then depleted and needed to be charged again. Therefore I donned my wellies and hit the Sett Valley Trail for a 2 hour walk. This was slightly less successful and i suspect that this was because the early morning sun had clouded over AND the charger was not facing the sunlight at all times.
Lesson Learned: Look, the damned thing works BUT you must keep in mind the following: 1. Direct proper sunlight will give you the best result, and 2. You shouldn't wait until you're down to the last bar of whatever device you wish to charge or you may get caught out. Be sensible - it's not called a trickle charge for nothing so manage your expectations!