I have had this charger for about 3 months now and it works very well. I have tried at least 2 other brands and they could not hold a charge long enough to charge my smart phone.The other brands only gave me half a charge. This product gave me a full charge every time. Just make sure you give it a full charge before you use it. If you have not charged it for 4 or 5 days it may not give you a full charge.