The secret of the 18650 lithium battery you don't know -part 3

4, high voltage

The voltage of the 18650 lithium battery is generally 3.6V, 3.8V and 4.2V, which is much higher than the 1.2V voltage of NiCd and NiMH batteries.

5, no memory effect

It is not necessary to empty the remaining power before charging, which is convenient to use.

6, the internal resistance is small

The internal resistance of the polymer battery core is smaller than that of the general liquid battery. The internal resistance of the domestic polymer battery can even be less than 35m, which greatly reduces the self-consumption of the battery and prolongs the standby time of the mobile phone. The level of international integration. This polymer lithium battery that supports large discharge currents is an ideal choice for remote control models and is the most promising alternative to nickel-metal hydride batteries.

7, can be combined in series or parallel to form a 18650 lithium battery pack

8, a wide range of uses

Electronic devices such as laptops, walkie-talkies, portable DVDs, instrumentation, audio equipment, model airplanes, toys, video cameras, digital cameras, etc.

Disadvantages

The biggest disadvantage of the 18650 lithium battery is that the volume has been fixed. It is not well positioned when installed in some notebooks or some products. Of course, this shortcoming can also be said to be an advantage. This is a lithium battery compared to other polymer lithium batteries. This is a disadvantage in terms of customizable and transformable size. It is an advantage over some products with specified battery specifications.

The 18650 rechargeable battery production needs to have a protection circuit to prevent the battery from being overcharged and causing discharge. The production conditions of the 18650 lithium battery are high. Compared with the general battery production, the 18650 lithium battery requires high production conditions, which undoubtedly increases the production cost.

The secret of the 18650 lithium battery you don't know -part 2

Lithium batteries are the same as 3.7V or 4.2V. It’s just that the manufacturer’s labels are different. 3.7V refers to the platform voltage (ie, typical voltage) that is discharged during battery use, while 4.2 volts refers to the voltage at full charge. Common rechargeable 18650 lithium battery, the voltage is 3.6 or 3.7v, when fully charged is 4.2v, which has little to do with power (capacity). The mainstream capacity of 18650 battery is from 1800mAh to 2600mAh (18650 power battery capacity is more than 2200~2600mAh.

What is the use of the 18650 battery?

The 18650 rechargeable battery life theory is cyclic charging 1000 times. Due to the large capacity per unit density, most of them are used in laptop batteries. In addition, the stability of the 18650 is very good at work. It is widely used in various electronic fields: it is often used in high-end glare flashlights, power supply, wireless data transmitter, electric heating clothing, shoes, portable instrumentation, portable lighting equipment, portable printers, industrial equipment, medical equipment, etc.

Advantages and disadvantages of 18650 battery

Advantages

1, large capacity

The capacity of the 18650 lithium battery is generally between 1200mah and 3600mah, while the general battery capacity is only about 800mah. If combined into a 18650 lithium battery pack, the 18650 lithium battery pack can easily break through 5000mah.

2, long life

The 18650 lithium battery has a long service life, and the cycle life can reach more than 500 times in normal use, which is more than twice that of ordinary batteries.

3, high security performance

18650 lithium battery has high safety performance, no explosion, no burning; non-toxic, non-polluting, RoHS-certified; all kinds of safety performance in one go, the number of cycles is more than 500 times; high temperature resistance is good, discharge efficiency is up to 100% under 65 degrees . In order to prevent battery short circuit, the positive and negative poles of the 18650 lithium battery are separated. So the possibility of its short circuit has been reduced to the extreme. A protective plate can be added to prevent the battery from overcharging and over-discharging, which also extends the battery life.

The secret of the 18650 lithium battery you don't know -part 1

A history of 18650 batteries?

18650 is the originator of the lithium-ion battery, a standard lithium-ion battery model that Japan SONY Company set in order to save cost. Among them, 18 means diameter 18mm, 65 means length is 65mm, 0 means cylindrical battery. The common 18650 battery is divided into a lithium-ion battery and a lithium iron phosphate battery. The lithium-ion battery voltage is 3.7V, the charge cut-off voltage is 4.2v, the lithium iron phosphate battery has a nominal voltage of 3.2V, the charge cut-off voltage is 3.6v, the capacity is usually 1200mAh-3350mAh, and the common capacity is 2200mAh-2600mAh.

The 18650 means 18 mm in diameter and 65 mm in length. The model number of the No. 5 battery is 14,500, 14 mm in diameter and 50 mm in length. Generally, the 18650 rechargeable battery is used in the industry, and the common ones are used in notebook batteries and high-end flashlights. According to the type of battery can be divided into 18650 lithium ion, 18650 lithium iron phosphate, 18650 nickel hydrogen (rare), the common 18650 is lithium ion.

What is a lithium battery?

Lithium-Ion Battery: Lithium-ion batteries are widely used because of their lightweight, large capacity, and no memory effect. Many digital devices use lithium-ion batteries as power supplies, despite their prices are relatively expensive. Lithium-ion batteries have a high energy density, and their capacity is 1.5 to 2 times that of nickel-hydrogen batteries of the same weight and has a very low self-discharge rate. In addition, the lithium-ion battery has almost no "memory effect" and does not contain toxic substances, which is also an important reason for its wide application.

In addition, please note that the external lithium battery is generally marked with English 4.2V lithium-ion battery (lithium battery) or 4.2V lithium secondary battery (lithium secondary battery), 4.2V lithium-ion rechargeable battery (charged lithium battery), so users who purchase the battery must look at the signs on the outside of the battery block to prevent the cadmium-nickel and nickel hydride batteries from being mistaken for lithium batteries because they do not see the battery type.