The charge takes less than two hours after the initial charge. My batter lasted me almost two weeks of non continuous shooting, so all in all probably 8-10 hours of serious continuous shooting. However if you are shooting a lot of indoor shots, it might last less as the live mode seems to burn battery a bit more than auto.
The PowerShot A2300 uses the same battery that most of the other PowerShot models use. (We've got an S90 and an S95 rolling around the house as well..) From absolutely dead to fully charged, the battery is in the cradle for about 90 minutes. On a full charge, my youngest hammered off about 400 shots (sans flash) and a few minutes of video without a problem. Your Mileage May Vary, but battery performance is one of the areas where the PowerShop holds up well in comparisons.