The ONLY reason I bought this charger was so that I could continue to charge my phone and other devices in the event of a prolonged power outage such as from a terrorist attack on the power grid or a major natural disaster. That means I need it to be able to work via solar energy. This charger does NOT do that. I've left it in the sun for days and it does not ever increase the saved charge. The lights blink as if it is charging but it simply isn't. I've tried trickle charging my phone while the charger is in the sun and all it does is deplete the charger to charge the phone. The ONLY way to charge this charger is by electrical outlet. This completely defeats the purpose of the charger.This charger DOES charge your phone very nicely, it's just that none of that energy came from the sun. You save nothing. You use just as much electricity whether you use the charger to charge the phone or connect the phone's charger to the outlet. It is basically a plain old power bank charger with a useless solar panel. I'm not convinced it is even a solar panel, but rather a light sensor that simply detects sunlight to make the little lights flash so you are duped into thinking it is charging via solar rays. The little lights activate and begin blinking as soon as you are near a window even before the charger is in direct sunlight.It's also possible that the solar panel is real but is too small to be effective, and that the little blinking lights actually use up any solar energy as it is created. Since I have had this charger there have been very few completely sunny days so I have not been able to do a true test. There was one stretch of sunny days and I had it sitting in the sun for those days and was able to charge my phone only 12% and I'm not even sure if that was from solar energy or residual energy from being charged from the outlet. But even if it was solar energy, that means it would take WEEKS to fully charge a phone. This is not practical at all and means the solar panel is essentially useless.Since I've missed the return window I am stuck with it. At least this charger works well as a power bank when charged from an outlet. I can get about 4 phone charges out of it before it completely runs out of juice. This when charging a phone from around 50% back to 100%. So if you let your phone go down to empty before charging, you might only get 2 full charges out of this charger. I have never had a power bank before so I don't know if that is normal or not. It also seems to charge my phone at just about the same speed as when I charge my phone from an outlet. I will just have to remember to keep this power bank charged and check it now and then so that in the event that I will need to use it, it will be ready to go.As far as the other features like the flashlight, and the whistle...I don't see why anyone would ever use it as a flashlight because that would deplete the charge and reduce your ability to charge your other devices. Also, the "SOS" setting is simply flashing of the light. It does not flash in the Morse code dot dot dot dash dash dash pattern, just on off on off on off. As for the whistle, I suppose I might use it one day in an emergency but that is if I remember I have or where it is. Most likely I will never use it.I would not recommend buying this charger if you are looking for one that is solar powered. If you are looking for a cheap power bank to take with you when your phone is running low on battery power, this might work well for that.