If that is a genuine concern to you, you're better off buying separate solar panels (even just the portable kind) if you expect to get any kind of usable energy. Not only is the area of solar panels that they put on those power banks practically useless, they also use the cheapest garbage panels available that are only good enough to power a handheld non-graphing calculator.
Well, when the grid breaks down, the solar bank is the only way we could charge our phones, though I think we'd have larger problems then.
If that is a genuine concern to you, you're better off buying separate solar panels (even just the portable kind) if you expect to get any kind of usable energy. Not only is the area of solar panels that they put on those power banks practically useless, they also use the cheapest garbage panels available that are only good enough to power a handheld non-graphing calculator.