The first thing you should know about batteries are that the battery is the e-cig. Some batteries of course last longer than others but really it has a lot to do with how much you’re vaping. I personally use the Riva 510 and my battery lasts me all day, but that again may not be the case for you as it varies from how much you vape. Some e-cig guru’s mod their battery but now a-days you can purchase things like screw drivers and provaris that are larger and have removable / rechargeable batteries inside. From what I understand they last quite a deal longer between charges.
One thing to keep in mind about batteries is the difference in manual vaping vs. automatic. If you are automatic vaping, then you might want to look into getting a e-cig that has a button and has to be manually pressed to activate it. By using an e-cig with a button, you can just imagine the amount of battery you would save vs. one that is automatic. I’m sure it’s quite safe to assume that larger batteries are ones that will last you longer, but don’t hold me to that. In circumstances you may personally find a smaller battery that could last longer. Before purchasing your e-cig, I would really do some research on them to see what would best suit your vaping needs.