The old battery in our Samsung phone wasn't holding charge. This gizmo came on time, and we took out the old and in with the new. Although it charged quickly, we noticed that the drain on the battery was much less, although it didn't seem to be great. Lasted over a day with limited use, before a recharge was necessary. It was better than the old one, I suppose, and the price was VERY good. I think the phone might be the problem, not sure if we really needed a new battery (after one year), but at least we can take this one out for a Samsung phone in the future if we need it.