Many people, and certainly those new to electronic smoking, usually look at an e cigarette kit as a single and individual entity, where batteries, atomizer, charger and cartridges are supposed to be all used in conjunction for the entire life of the product.nIn reality, this could not be further from the truth. Whether the kit included an atomizer or a cartomizer, these atomization devices come with a limited lifespan. Usually, an atomizer needs to be retired after a month or two of use, when performance decreases and the device no longer provides a satisfying vaping experience. Cartomizers have varying lifespans, but they too need to be periodically replaced.nThis means that sooner or later you will need to buy extra atomizers, cartomizers or both. The selection of atomization devices is vast, and there are many choices for the most popular battery threads out there. That is why the batteries should actually be the main concern when purchasing an e cigarette kit. While atomizers and cartomizers are replaced often, the batteries will last for at least 300 charge cycles, meaning they will be with you possibly for years.nThe trick, of course, is finding devices that are compatible with your chosen kit. All electronic cigarette batteries work in very much the same basic way, but the difference that dictates if an atomizer is compatible with it or not, are the battery threads – or to put it simply, if the atomizer will screw on to the battery properly or not.nCurrently, there are two main threads manufacturers use: 510/eGo and 901/808-D. When shopping for electronic cigarettes, most vendors will advice users on what thread each kit uses. Similarly, they will sell atomizers and cartomizers separated by thread type.nOut of both those threads, the 510 (also known as eGo in ‘fat battery’ kits) is by far the most widespread. Any battery rated as a 510 or eGo thread will be compatible with other 510 threaded atomizers and cartomizers. In fact, most users who buy 510 class e cigarettes eventually buy a cornucopia of different atomization devices, searching for the one that satisfies their cravings, practical needs and smoking style the best.nThe 901 thread (also known as 808-D), while not as popular as the 510 above, is still widely used on slim type e cigarettes and also has a large selection of atomization devices available to them.nWhen selecting a new electronic cigarette kit, and most certainly the first one, compatibility is not the only consideration. Another very important aspect is style vs. the ever mystifying mAh ratings.nIn a nutshell, mAh stands for ‘Milliamp Hours’, and it is a measure of how big a charge a battery can hold. The higher the mAh rating, the longer the battery will last between recharges. As can be expected, a higher mAh also means a larger battery, and most of the so-called ‘fat battery’ kits like the eGo style devices range between 650 to 1,200 mAh. Going for something that looks and feels like a traditional cigarette means using a much smaller battery, and therefore, sacrificing charge capacity.nFor those who want a ‘slim cig’ kit that will look much closer to a tobacco cigarette in size and shape, it is highly advisable to look for a compatible PPC, or personal charging case. PPC devices are usually made to resemble a high-tech version of a pack of cigarettes, and fulfill two main purposes. The first one of course, is to provide a hard case to carry electronic cigarettes in, but more importantly, they can also use their internal li-ion battery to recharge depleted e cigarettes on the go, making up for the reduced charge capacity of the smaller batteries.nWhile compatibility and charge capacity are the two main considerations when judging an electronic cigarette kit, there is also personal taste. E cigarettes are made in many shapes and sizes; from cigarettes to cigars and steampunk-looking cylinders to classy vintage pipes and everything else in between. There is plenty of variety out there to suit any taste and personality.