Yup, what they all said.  Not too much more I can add.  And no "punching."  
 
I find the regular 78mm Volt 
batteries will usually last me 2 to 3 hours of standard use before recharging (ritual, pick it up/put it down, come back after a bit, rinse/repeat).  If one vapes the marathon, not putting it down, maybe an hour.  The life expectancy is reported at approximately 300 charges.  With as many of the 
batteries as I have, I don't think I'll reach the individual 300 charges per battery any time soon.  Oh, and a minimum of 3 
batteries on hand, as CatLady and Cindy indicated.  Me, I have at least one of each color, in each size.  
 
I like just about all the prefilled carts from SI, and I top them off with their liquids as I go for about the aforementioned 8 to 10 fills before needing a new cart.
The X2 is nice, has more power, will last longer between charges and will use either the carts or the clearomizers.  It will burn through carts a little faster than normal, but I actually prefer the carts over the clearomizers.  I have used both.