My first kit came with two 1100mAh eGo-C Twist batteries and they've been great. I don't use them as often as I used to now that I have other mods to play around with, but I still use them occasionally on the go and they work just like they did when I bought them. The twisty part is a little looser on one than it was when I bought it, so I sometimes accidentally change the voltage when it sits in a pocket, but that's not a big deal. Take a burnt hit or one that barely hits at all and you'll know about it pretty quick! You can adjust the voltage on them from 3.2V-4.8V, which gives a decent range for many clearomizers. They're not very expensive, so think about picking up at least two... that way you can always have a spare while you charge the other one.e