How long will the fan run for on this solar power bank? plus running 12v fan off 12v solar panel?

Okay I've got 2 things here but a little intro first: I'm going on holiday and sometimes there's no power and it's really hot. So I want to make an eco-friendly cooling solution. Amazon/ebay have these Solar power banks that seem to have good reviews. If it is 5000mAh, how long will a USB fan run for? I did do some calculations (but I lost them) and I got about an hour or so.      Secondly, I found this solar power trickle charger, and I was wondering can use to directly run a 12v fan like this one? Will be work as long as the solar panel is in the sun? I can't see any current requirements for the fan, so it will it end up running really slow? Any help with this is appreciated! Thanks!

Can't run a 12V fan with a 12V solar panel unless that panel can output enough current to runt eh fan of the panel is charging a 12V battery to run the fan.

Run time depends on the ampere hours availble.
So on your bank 5A for an hour, 0.5A for two hours, 0.25A for 4 hours - you get the picture....
IMHO you are better off with a 12V system, including a battery and to run 12V fans directly.
At least it would preven the additional losses from converting the voltages.
And no, you can not use a charger to run a fan.