Most likely your carto will need to be replaced before the atty goes out. Depending on what type of juice you use, they will clog up. At that point, I just toss them. Some people try and boil them, but its hit or miss. Sometimes they clean, sometimes they die. Remember this, the higher the VG content, the thicker the juice. The thicker or darker the juice, the faster it will clog you cartomizer and the slower it will wick. Personally, I use 70pg/30vg. I just tossed out 2 cartos that I have had for 6 weeks now. On average, I get about a month using them, but I am switching away from them.
At home, I use the Vision Clearomizers (I have the Volt X2 ones but they are the same thing). The Clearomizers are nice, but they have limitations. The biggest one, which, if you have been reading around I;m sure you know, is that certain flavorings in juices will melt them. Cinnamon especially but generally anything highly acidic. Also, they aren't as portable as cartomizers. If you turn them upside down, they will leak.
Being that I own a landscape business, I need something that is portable that I can take on the road with me, which is why I have stuck with the cartomziers. But since trying the pheonix and fluxomizers, I am transitioning over. The phoenix is pretty much a combination of a clearomizer and a cartomizer. It is the size of a carto, but has the wicking of a clearo. The only downside is that you have to fill them with a syringe, but its not difficult. If you look on their website, he has a video showing how to do it.
On a side note, Smokeless Image is supposedly getting clearomizers that wont melt. They are also getting something that is similar to the phoenix but wont need a syringe. They are supposed to get them in by July. Anything they sell will fit your V2 and they are very reasonable in price. Customer service is awesome. Generally, they ship within an hour of you placing the order.
For what its worth, if you need more batteries, I suggest considering a volt battery. They are less than half the price of V2 and you can use everything you own for V2 and just mix the SI one in. A 380mah battery from V2 is $30 and is almost twice as long as the SI 380mah battery. The SI version is only 78mm and costs $13 before coupons. They always have a coupon, including the Fathers day one for 25% right now. If you want a bigger battery, the X2 they sell is the same exact thing as a KGO but with 808 threading. So again, you could use all your v2 stuff on it.
Anyway, just wanted to let you know. Please dont take this as insulting your V2, I'm not. It's not a bad product, just very expensive for a mini. I am all about saving money, and when I see that someone can get a superior product for less, I try and tell them. The only reason I mention it is because you can mix them, so if you need extras, you can use the volt stuff.