Yup, probably. The Power Banks are not my design, just something I've gotten to improve the functionality and usefulness of the Solar Cells. In fact you can find heaps of similar Power Banks online or in store.
I've spent several months testing out various Power Banks from a variety of supplier and makers. While many online look the same, or similar, quality is a massive issue. Some of those super cheap Power Banks on eBay are that way for a reason. They're factory rejects or old models, or are using just insanely cheap parts. I know, I've tested out heaps of them.
So be assured, if you're getting a Power Bank it's not going to be cheap junk from some no name maker. You're getting a well made and quality Power Bank that'll work well with the Folding USB Solar Cell.