Is the solar panel waterproof? Can I use an extension cable?

We have waterproof treatment for solar panels, but I do not recommend you use them in the rain. Portable solar panels cannot be fully waterproofed like hard solar panels. Long-term exposure to rain may reduce cell efficiency. The length of the solar charging cable is 16ft long. We also provide the extensions on the website. Please note that the charging efficiency may be reduced due to the charging cable being prolonged. It might require more time to finish charging with extension cables.