This battery is designed to enjoy optimum performance with your Samsung Galaxy S5 handset. With it your device will be powered longer and the battery will sustain a greater amount of charge. As a Samsung authentic accessory, it helps users appreciate their device that bit more. This Lithium Ion (Li-Ion) replacement battery from Samsung is always guaranteed to charge to the optimum level. The battery case is elegantly styled and great care has been taken to ensure that the design from the original handset is matched. This replacement battery has been manufactured using only the highest quality cells. The battery life of a handset can vary greatly depending on how you use your device and your battery charging habits. If your device is running out of battery quickly, or takes a long time to start up (or even does not start up at all), then you may need a replacement battery.