I picked up one of these because of how cheap it is; can charge anything with a USB port, laptops, phones, torches, etc.

- https://www.action.com/de-de/p/3222881/re-load-solarmodul/

- https://www.action.com/de-de/p/3222880/re-load-faltbares-sol...

Despite the low capacity, given what can be done with a phone and a laptop, this is still potentially useful.