Digital camera battery capacity ratings
mAh is the measure of the total capacity of a battery. Capacity refers to how much charge a battery holds after it is fully charged. The higher the number (eg. 1000 mAh, 2,300 mAh, 2,500 mAh) the longer a battery will last.
These ratings are only applicable when comparing the same types of batteries (NiMH to NiMH, not NiMH to Alkaline).
NiCad and NiMH batteries are generally recommended for use for high-drain electronic gadgets such a digital cameras. For slow-draining devices, high rated alkaline batteries are generally better at providing their full capacity.
High rated batteries = more photos?
In theory, the higher the battery rating, the more photos you can take on a single charge. In practice, many factors come into play as to the number of photos you can actually take before batteries are depleted.
The number can vary depending on the power-consuming features you use such as the built-in camera flash, LCD monitor and zoom lens. If you digital camera has a built-in power management feature, use it. The LCD will power down according to the time-frame you select in the menus. Using a memory card reader to transfer images, instead of a cable from camera to computer, will also save battery power.