Solar Power Banks

[SparePartz]

Thinking of one to charge two phones. Any recommendations for a brand? They all look the same and all have similar reviews!
Do they "keep" as in can you stick them in the back of a cupboard until you need them and they will still work? Or do they degrade over time?
Do any work on a normal day or do they all need bright sunlight?

I've never heard anything good about them. I went with a power bank and travel solar panel separately for camping. Works well in bright light, ideally sun.

Just checked my Anker power bank that I haven't used in 6 months and it's still fully charged.

Oh, that's a good tip. Which travel solar panel do you have?
What size power bank do you have and which devices do you use it for?

The panel is 5 or 6 years old and I can't remember.
The power bank was this one, but there are more powerful and cheaper ones about. Anker is a good brand though. 20,000mAh does 5 charges of my Galaxy 8.
Good for my camera too.

They don't charge very fast. They may need proper outside rather than window.