At the camcorder's product page at Canon.com, there is a "Downloads" tab. Download the manual. "Best case" battery life is usually in there. My guess is 20 minutes for HDV video recording. Where do you start the "time" for the photos? Power up, take the picture... power down? Take lots of pictures before power down? Best not to use photos use for battery life on a camcorder.
aLSO I want to buy an additional battery to take to make sure I will always be ready when I am out on tours and want to know what is the max battery that I could get and is there a generic brand I could get that would be less expensive & work just as well.
Good idea with the additional high capacity battery. I get the ones from the manufacturer - they cost more, but I know they will work. I do not recommend the third party batteries. I get two high capacity batteries - one is charging while the other is in use. I rarely use the one that came with the camcorder.
Would the 2nd battery have a different model number it is has a longer time on it?
Yes. The Canon web site will have different part numbers for each different optional battery depending on the camcorder it is used for and the charge time.