I'm looking for a quality solar Power Bank with reasonable capacity, say >10,000mAh.
Does one that has only USB-C output, charge micro USB devices properly. IE QC/FC? I ask because I do have a phone to repair that is C. I'm assuming you can get C-to-micro cables but I haven't looked.
Lighter the better, so Lithium Polymer probably the way to go it seems.
Any suggestions?
Agree with this. There's plenty of good quality solar panel chargers out there and I'd just buy one of those and connect it to a good quality power bank.
Agree with this. Leaving your battery under a hot panel is a recipe for disaster
look up "goalzero"
To make any impact in terms of charging via solar, you will need a big panel.
The dinky little ones smaller than A4 paper would take all day to get close to charging it.
Get one with a detachable solar panel so the battery pack itself can be kept in shade. Lithium batteries degrade if heated, and in the middle of summer a black item placed out in the sun can easily get to 70C here.