I ordered this product so that I would be able to use my cell phone chargers for my car in my office during the day instead of carrying a seperate charger. I ordered two initially. One was damaged upon arrival and the other stopped working on it's second use. The replacement sent works great and serves it's purpose. so I think it is mostly just the luck of the draw if it is going to work or not. Either way, it was an excellent price, especially compared to buying another charger!