I recently picked up a Jackery 500: Jackery Explorer 500 Portable Power Station I also picked up a cheapo solar panel off of amazon. The reason I bought this solar panel is that it was half the price of the Jackery solar panel and it was also waterproof. However, I attached the solar panel to the Jackery and it barely charged it at all. After a couple hours it went from 46 percent to 47 percent charged. So I returned the solar panel. Now I'm wondering if I purchased a Jackery Solar panel, would it be equally inefficient? Jackery SolarSaga 100W Solar Panel My goal is to have a solar panel that I can put out on a cloudy day in the morning and have the Jackery completely charged by the time the sun goes down. Does anyone here know what kind of set up I'd need to achieve this goal? Do I need a bunch of solar panels?