The first generation of electronic cigarettes has an electronic controller that is separate from the battery. It controls the 3.7v rechargeable lithium battery to discharge current. It uses a three-stage structure of batteries, atomizers and cartridges. The battery controller limits the voltage to 4.2v through the micro board and outputs a voltage of 3.3v. The early second-generation e-cigarette model included a 14500 lithium battery case (for example, the early e-cigarette prototype product, which was first discussed in the foreign e-cigarette forum in 2009, adding a battery box to the electronic cigarette), a two-headed connection Bronze pipe for batteries (early prototype products). The first commercial second-generation e-cigarette prototype was made in the UK. The most typical feature of this prototype is that it has a larger lithium battery that is more stable for longer use after each charge. Using a resistor to reduce the battery voltage to 5V, this prototype was considered the template for the most other products at the time. Limited to consumer perception, business success is limited. The third generation of electronic cigarettes is a true electronically regulated device with great progress. E-cigarettes from the beginning of a plastic box with two lithium batteries, gradually turned into a box style, in the three generations of electronic cigarette battery box, there are still two lithium batteries, usually 7.4v can reach up to 8.4v, but An electronic voltage regulator controller is installed to stabilize the battery output voltage control at 5V. The three generations of electronic cigarettes also have a 5v output voltage, using lithium batteries, and charging three advantages, reaching the ultimate goal of battery discussion on the network.