Battery works well as a backup. I haven't tested the capacity, but I suspect after using it a few times it might be below the stated capacity of 1400 mAh. The capacity of the battery that came with the camera is stated as 900 mAh, and it seems to last longer. Having said that, it is a great battery as a backup. I have used it several times to keep my Fuji camera going at the end of the day after the main battery was exhausted.