JNEESYAN 20000mAh Portable Power Bank Solar

www.amazon.com/gp/product/B0B3N176LG

only thing I did not mention was the heat warning. Like all lithium batteries excessive heat can cause damage or leaks...so do not let it get too hot...It is July here and I used it on a 95 degree day. It felt hot so I put it on a damp rag to disperse some of the heat. The case is pretty robust and I would not worry too much about it getting wet from rain or from sitting in wet clothing based on this.