Let me tell you how I feel about the product I just bought. Mini power plant functioning at peak efficiency, expertly constructed. Despite my heavy use, I have never experienced any noise from the battery or signs of overheating. It is everything it claims to be. The setup doesn't take up much room, and I can charge my phone, tablet, and even laptop from the battery it generates; but, I have not yet been able to charge the battery to 100%. No complaints, it's a perfect solution.