We have one from the dreaded Ebay that has a solar charger on it and 2 usb ports for simultaneous charging and was about 15 quid. It has a brand name of x-Dragon (chinese rip off presumably)
It has 300,000 mAh s which sounds like a lot and comes with a compass that i am never likely to use.
Its smaller than my phone and recharges on the beach (It also has a torch function i wont ever use)
Had it a couple of years and still works
Just bought a jump starter and that will charge phones etc as well.
Cant see the point of a battery pack for the tv when a leisure battery does the job.
A 300Ah portable battery; there’s a thing!
I‘ll have a few of those in my van if you don’t mind. ?
Ian