rs replied: "Probably about 200 pictures.
Ways to make the battery last longer:
Turn off the viewfinder
Turn off picture review or make it last as short as possible so you can see if your picture was out of focus or blurred by motion.
Don't turn it on and off unless you are not shooting for several minutes. Extending and retracting the lens drains the battery.
You should get at least two spare batteries. You can usually get Li-Ion clone batteries on ebay very cheaply.
You can also keep 1 Lithium battery (non-rechargeable) for that time when you absolutely positively must take those shots no matter what."