Solar power banks for camping

hey everyone,
are there any campers out there that have any experience with solar power banks (of the affordable variety). my wife and daughter are heading out for a camping trip soon and their gonna need more charge then our little travel bank can offer and I was looking at solar panels/power banks. i admit i'm a little at sea. anyone have a recommendation for something that will keep them in juice for a 4 or 5 day trip? devices to be upkept include, my wife's phone, a portable microscope that uses wifi to send pictures to said phone, a few usb charged lights and similar other things.
I am NOT a camper by any means so I'm not really sure exactly what to look for. our budget is not huge (hopefully $60us or under, but if it will last a long time we can go a little over that).

Long shot, but if you use Ryobi tools, they make a 18V battery inverter that might work.

Do they even need an AC outlet, or will USB power be enough for everything they plan to do? That portable microscope is the only one on your list that I'm unsure about. Solar power is great, but it's slowwwwwww, and it really needs direct line of sight to the sun (no clouds, trees, etc) to be really effective. A couple of 25k+ mAh battery packs for ~$25 each might be good enough; each should hold enough to recharge a phone 8-10 times.

If you really want to get something with a solar backup, maybe something like this fits the bill, coming in just under $60 on sale right now. It has a 20k mAh battery with an unfoldable 1300 mAh (max) solar charging panel for emergencies. Charge it at home, and trickle-recharge it via solar. 20k mAh battery is a pretty good capacity to start off with, and 1300 mAh solar charging is the fastest I've seen in this price range - it's still not FAST though; it would take over 15 hours to charge that 20k battery via solar, under perfect conditions.

I haven't used this product personally; no idea if it actually functions as it says it does. These "BLAVOR" products seem to be pretty well reviewed on Amazon, at least.

USB is actually what i was looking for, sorry that i wasn't clear that's my bad. if anyone has used one i'd really appreciate an opinion, good or bad so I can narrow things down, gotta order today to get things in time to pre charge and prep for the camping trip.

I'm assuming you're car camping (or you wouldn't be lugging a microscope?).

Assuming so, lucky you, because your car IS your power-bank. If it's fairly new, it's even got USB ports built in!

Particularly combined with your existing travel bank - you just use the car to recharge that when it runs low.

The microscope is just a little tiny thing (my 5yo cam carry it in her hand easily), very cool for curious people witha small pocket to spare.
Ended up just getting a regular 20000mah battery pack, that plus a 10000 should do fine.
They are technically car camping i guess but once they're at the site to it's all outdoors all the time and the car is a long ways away so Car recharge isn't practical.