As a heavy skeptic, I can honestly say this charger works. Depending on the light source, charging can be slow to fast, but it beats a dead phone, or other, battery. Used it multiple times outside at all day events where no charge source was available and it maintained my battery. The overload feature kicked in a few times with no damage, too. Wish the spring clip and split ring were beefier, and that it came with a storage pouch, but otherwise a nice product.