In reply to malk:
> your Anker powerpoint folding panel is 21W?
Ah, I see the OP is referring to the same thing. My mistake. I thought they were referring to some Anker product similar to the Goal Zero, hence the reference to "Plain Solar Panels with a regular battery pack" - which is exactly what the Anker product is. The Goal Zero panels look way too small to me, but I assume people have had success with them.
In that case, I would recommend the Anker 21W and s suitable battery pack (I use an Anker PowerCore 20100).
You will find the sun at AD Base Camp to be quite strong, and ample to fully charge one of those battery packs in less than a day.