I recently bought this solar panel product right exactly to what you are looking for here's the link
https://agreenorigin.com/camping-solar-panels/ it's the GGX ENERGY High-Quality 7.2W Portable Solar Charger for Mobile Phone iPhone Folding Mono Solar Panel+Foldable Solar USB Battery Charger...
I choose RAV power bank that I purchase here https://www.amazon.com/dp/B019IFIJW8/?tag=cpf0b6-20 —I was able to use it to charge my Nintendo switch while playing it without battery discharging or dropdown
I recently bought a High-Quality 7.2W Portable Solar Charger for my iPhone here...
Will presuppose, 6 h full sunlight, and a top notch MPPT modulator, no trickle charge, and total 80% efficiency.
50W (STC labeled, not the real world power) usually has Vmp=17V, Imp=2.9A
Case 1. Li-Ion battery Turnigy Graphene Professional 3000mAh 3S 15C LiPo
This tipe of battery suports max 5C...