18650, which we often say, actually refers to the shape specification of the battery. It is a standard battery model set by Sony Company in Japan in order to save costs in those years. 18 represents the diameter of 18mm, 65 represents the length of 65mm, and 0 represents the cylindrical battery. 18650 battery originally refers to nickel hydrogen battery and lithium-ion battery. 

Since nickel hydrogen battery is less used now, it now refers to lithium-ion battery. The nominal voltage of each 18650 Li-ion battery is generally 3.6V, 3.7V, 3.85v, etc; The discharge termination voltage is generally 3.0V, the minimum is not more than 2.5V, and the common capacity is 1800 · 3600mAh. If it is higher than 3600mAh, it may be a false mark.

Since Sony launched it in the 1990s, the 18650 battery has been enduring. 18650 battery is widely used in the industrial field and electronic equipment such as notebook computers, interphones, instruments and meters because of its large capacity, good energy storage efficiency, good stability, no memory effect, high cycle life, and no toxic substances. Even the world's hottest Tesla electric machine uses the 18650 battery pack provided by Panasonic.

After 30 years of development, the preparation process of 18650 battery has been very mature. In addition to greatly improving its performance, its safety is also very perfect. In order to avoid the explosion of the sealed metal shell, the current 18650 batteries are equipped with a safety valve on the top. The safety valve is the standard configuration of each 18650 battery and the most important explosion-proof barrier. When the internal pressure of the battery is too high, the top safety valve will open to exhaust and depressurize to avoid explosion. However, after the safety valve is opened, the chemical substances leaked from the inside of the wire transfer will react with the oxygen in the air at high temperature, and there may still be a fire. In addition, some 18650 batteries also have their own protection plates, which have safety functions such as overcharge and discharge and short-circuit protection, with high safety performance.

The previous mobile power explosion was all caused by some unscrupulous manufacturers using substandard 18650 batteries or even second-hand waste batteries to save costs. At present, the 18650 batteries produced by major manufacturers such as Panasonic, Sony, Samsung and so on are actually very safe. Moreover, the 18650 batteries have a very high utilization rate. We can use them correctly in daily use and avoid short circuit, damage or high temperature of the batteries. 

We do not need to worry about the explosion of the batteries. We can't overturn a boat of people with a bamboo pole, and characterize the safety of 18650 with inferior quality products!