The battery is a 3.6V 1.1Ah (nominal) device. Li+ batteries are considered discharged at 3V per cell. V(max) during charge is 4.2V, incidentally.
To test it, discharge through a dummy load from fully charged at the C rate (1.1A) until it reaches 3V - that should, quite reasonably, take an hour. You can discharge more slowly if you wish, especially if you know the load characteristics of your camera. Note that the usual discharge characteristics for Li+ are