Apologies if a repeat.
Have any of you tried the Grape Solar 'Granite' recharger?
USB, large and small ports.
I've been told its good for about 14 GoPro recharges
Works of course on Cell Phones too.
You can recharge it off any USB. Including your solar stuff.
However, it can take about 4 hours to recharge from your wall outlet with USB connector.
So don't expect portable solar to do much.
Grape Solar Granite
8,800mAh Rechargeable Lithium Portable Battery Pack for Cell Phones, Smartphones and Other Portable Electronics
$35.03 & FREE Shipping from the usual.
Grape is a solar company and does a lot of solar business through Home Depot where you can get one for $45 with in store pick-up.
Solar Compatible 8800mAh Lithium-Ion Battery
Patented Auto-On/Auto-Off feature to maximize battery life
1 micro-USB input, 1 USB Output, recharges via included micro-USB cable
6.4 x 1.8 x 0.9 inches.
solid and feels a little heavy. In a good way. 11 ounces
Don't know about packing a lithium ion battery like this on commercial aircraft.
This source is also $45 but link has a good picture.
(The smaller Grape Solar Wand
is only 2,200mAh)