Complete Analysis of 18650 Lithium Battery Knowledge

Complete Analysis of 18650 Lithium Battery Knowledge

More than three hundred years ago, Benjamin Franklin began to capture thunder and lightning, which opened up people's 

understanding of thunder and lightning, and also opened up people's understanding of electricity. From that time on, many 

people were thinking about how to store the captured electricity, so Gradually, things like batteries came into being. Indeed, as 

a very important invention in history, the emergence of batteries has indeed solved many problems and greatly improved the 

efficiency of various lives. The emergence of hammer batteries has made people even more interested in batteries. The 

understanding of electricity is getting deeper and deeper. The 18650 battery is a kind of hammer battery that has been used 

for a long time and still exists. The shadow of 18650 battery can be seen in many places and fields, because compared with 

other batteries, this battery has The advantages are very obvious, and the safety is relatively good, and it has even been used 

in large equipment. This article will introduce you to the knowledge of 18650 batteries and introduce why explosions occur.

Advantages of 18650 battery

It is generally believed that when the no-load voltage of the battery is lowered below 3.0V, it is considered to be exhausted 

(the specific value depends on the threshold value of the battery protection board, such as as low as 2.8V and 3.2V). Most 

lithium batteries cannot be discharged. The no-load voltage should be lower than 3.2V, otherwise excessive discharge will 

damage the battery (generally, the batteries on the market are basically used with a protective board, so excessive discharge 

will also cause the protective board not to detect the battery, making it impossible to charge the battery ). 4.2V is the limit 

voltage for battery charging. It is generally believed that the battery is fully charged when its no-load voltage reaches 4.2V. 

During the battery charging process, the battery voltage gradually rises from 3.7V to 4.2V. The empty battery cannot be 

charged during charging. The load voltage must be charged above 4.2V, otherwise the battery will be damaged. This is the 

special feature of lithium batteries. Generally speaking, 18650 batteries have the following advantages.

1. Wide range of use

Laptop computers, walkie-talkies, portable DVDs, instruments, audio equipment, model aircraft, toys, video cameras, digital 

cameras and other electronic equipment.

2. Series connection

Can be combined in series or parallel to form 18650 battery pack.

3. Small internal resistance

The internal resistance of polymer batteries is smaller than that of ordinary liquid batteries. The internal resistance of 

domestic polymer batteries can even be below 35m.2, which greatly reduces the self-consumption of the battery and 

extends the standby time of the mobile phone. It is completely possible Reach the level of international standards. 

This kind of polymer hammer battery that supports large discharge current is an ideal choice for remote control 

models and has become a promising alternative to jin-hydrogen batteries.

4. No memory effect

There is no need to drain the remaining power before charging, which is convenient to use.

5. High voltage

The voltages of 18650 lithium batteries are generally 3.6V, 3.8V and 4.2V, which are much higher than the 1.2V 

voltage of tin and gas batteries.

6. High safety performance

18650 lithium battery has high safety performance, does not explode, does not burn: non-toxic, non-polluting, 

passed ROHS trademark: various safety properties are integrated, the number of cycles is more than 500 times, 

good high mixing resistance, discharge efficiency under 65 degrees up to 100%. In order to prevent the battery 

from short circuit, the positive and negative poles of the 18650 battery are separated, so the possibility of short 

circuit has been reduced. A protective board can be installed to prevent the battery from overcharging and 

over-discharging, which can also extend the service life of the battery.

7. Long service life

The 18650 lithium battery has a long service life, and its cycle life can reach more than 500 times under normal use, 

which is more than twice that of ordinary batteries.

8. Large capacity

The capacity of 18650 lithium battery is generally between 1200mah and 3600mah, while the general battery capacity 

is only about 800. If 18650 batteries are combined to form an 18650 lithium battery pack, the 18650 lithium battery 

pack can easily exceed 5000mah.

Application of 18650 lithium battery

The application of lithium secondary batteries in the energy battery industry benefits from their superior performance. 

With the continuous development of lithium secondary battery technology, it has been widely used in our daily lives. 

Rechargeable batteries that have been used multiple times are increasingly favored by consumers. Paying attention to 

the energy battery industry and fully understanding batteries will allow us to do To "for my use", currently 18650 

management batteries have certain advantages in the following fields:

application.

1. Energy storage category

Mainly used in base station power supply, clean energy energy storage, grid power energy storage, home optical 

storage system, etc.

2. Power type

Mainly refers to electric transportation, electric bicycles, new energy vehicles, etc.

3. Digital

Mobile phones, tablets, laptops, electric toys, MP3/MP4, headphones, power banks, model aircraft, mobile power supplies, etc.

Why do 18650 lithium batteries have a history of explosions?

The vast majority of 18650 batteries are packaged in steel cases. Batteries of poor quality have no protective function. 

When overcharged (overcharged), the internal pressure will increase sharply. When the endurance value is exceeded, the 

battery will explode. Problems such as short circuit, excessive temperature or the battery being squeezed, deformed or 

even punctured may cause the battery to explode. After 30 years of development, the 18650 battery preparation process 

has become very mature. In addition to greatly improved performance, its safety is also very complete. In order to avoid 

the explosion of the sealed metal casing, 18650 batteries are now equipped with a safety valve on the top. The safety valve 

is standard for every 18650 battery and is also an important explosion-proof barrier. When the internal pressure of the battery 

is too high, it will The internal safety valve will open the exhaust and reduce pressure to avoid explosion. However, when the 

safety valve is opened, the chemicals leaked from the battery will react chemically with oxygen in the air under high temperature 

conditions, and a fire may still occur. In addition, some 18650 batteries now also come with a protective board, which has functions 

such as overcharge, overdischarge and short circuit protection, and has very high safety performance. The previous explosions of 

mobile power supplies were all caused by unscrupulous manufacturers using substandard and inferior 18650 batteries to save costs, 

or even second-hand waste electricity. At present, the 18650 batteries produced by major battery manufacturers such as Panasonic, 

Sony Star, etc. are actually very safe, and the usage rate of 18650 batteries is very high. We can use it correctly in daily use and swim 

without battery damage. Or the temperature is too high, there is no need to worry about the battery exploding.