Moondog55 wrote:Is it robust and weatherproof enough to strap onto the back of the rucksack and use it while mobile?
I did exactly that on quite a few days in Nepal. Walking with the sun behind, it was clipped to the pack, so that one panel was on the top flap of the pack, and one panel down the back. Not the most efficient in charging, but it worked. The device you are charging can be fussy though. For example, one of the AA chargers I took didn't like the USB voltage dropping to under 4.5V and wouldn't start charging again even when the voltage went back to 5V (like when the sun gets blocked by clouds). But I had no problem with the other AA charger, and the lithium ion battery pack.
Sort of like this picture but I had mine higher up on the top of my pack.
When walking into the sun, I had it strapped to the front like a bib, and had two clips to the hip strap to stop it flapping around. Yes, you look like a dick, but when you don't have a plug in power source, it worked nicely. I had it charging my Sony camera directly via USB cable, and it charged a flat battery in about 2 hours while walking. But we were walking to Dingboche on a clear sunny day with snow covered ground.
It worked better on acclimatisation days when you could set it up facing the sun and charged batteries faster. I carried the GZ Nomad 7, and my walking partner who was taller used the three panel Instapark Mercury 10.
The panel is pretty hardy, the only concern I had was the panel connection at the folds, but mine have been used for 2 years and haven't had an issue. I've picked up a smaller Sunkingdom 5W panel after some discussion on the torch forums, and it seems good to charge up smaller 18650/14500 batteries but understandably is a bit slower to charge AAs.
I've not gotten the panels wet, as usually if it was cloudy or rainy, there wasn't enough sun to charge and it stayed inside the pack.