What are the use of 18650 lithium batteries?

　　Author ：Iflowpower – Leverantör av bärbar kraftverk

Use a wide range of laptops, walkie-talkies, portable DVDs, instruments, audio equipment, models, toys, cameras, digital cameras, etc. Electronic devices 18650 are the nasal ancestors of lithium ion batteries - Japan Sony has been settled in order to save costs. Standard lithium-ion battery model, wherein 18 indicates a diameter of 18 mm, 65 represents a length of 65 mm, 0 is represented as a cylindrical battery.

Common 18650 batteries are divided into lithium-ion batteries, lithium iron phosphate batteries. The lithium-ion battery voltage is a nominal voltage of 3.7V, the charging cutoff voltage is 4.

2V, the lithium phosphate battery nominal voltage is 3.2V, the charging cutoff voltage is 3.6V, the capacity is usually 1200mAh-3350mAh, the common capacity is 2200mAh-2600mAh.

Li-Ion, LithiumBattery: The lithium ion battery has the advantages of light weight, large capacity, no memory effect, and thus obtains a general application of 18650 lithium battery 18650 lithium batteries - Many digital devices are powered by lithium-ion batteries Although it is more expensive although the price is relatively expensive. The energy density of the lithium-ion battery is very high, its capacity is 1.5 to 2 times the same weight of NiMH batteries, and has a low self-discharge rate.

In addition, the lithium-ion battery has virtually no "memory effect" and the advantages of no toxic substances are also important causes. Also note that the outside of the lithium battery is generally marked with English 4.2VLithiumBattery, 4.

2VLithiumsecondaryBattery, 4.2VLithiumionRechargeablebattery (charging lithium battery), so users must see the signs of the appearance of the battery block when purchasing batteries. Prevent cadmium nickel, hydrogen-nickel battery, misunderstanding because there is no design type.

Lithium battery standard 3.7V or 4.2V is the same.

It is only the same as the manufacturer's labeling. 3.7V refers to the platform voltage (ie, typical voltage) discharged during the battery, and 4.

2 volts is the voltage at full charge. Common can charge 18650 lithium battery, voltage is standard 3.6 or 3.

7V, full of electricity is 4.2V, this follow-up (capacity) is not large, 18650 battery mainstream capacity from 1800mAh to 2600mAh, (18650 power battery capacity) More in 2200 ~ 2600mAh), the mainstream capacity or even the standard 3500 or 4000mAh or more (remind everyone, the domestic battery "having 3350mAh or more in the market is likely to be fake, the largest capacity of domestic production 3350mAh. ).

It is generally considered that the no-load voltage of the lithium battery is more than 3.0V, which is considered to be electrically used (the specific value needs to see the threshold value of the battery protection plate, such as low to 2.8V, and 3.

2V). Most lithium battery discharges cannot discharge the no-load voltage or less, otherwise excessive discharge will damage the battery (the lithium battery on the general market is basically used, so excessive discharge can also cause the protection board to detect Go to the battery, can't charge the battery). 4.

2V is the highest limit voltage of the battery charge, which is generally considered to charge the no-load voltage of the lithium battery to 4.2V is full. During the battery charging process, the voltage of the battery gradually increases to 4.

2V, and lithium battery can not be charged. The no-load voltage is more than 4.2V, otherwise the battery will also be damaged, which is a special place for lithium batteries.

18650 battery life Theory is a circulating charging 1000 times. Since the capacity of the unit density is large, most of them are used in laptop batteries, except for 18650 lithium batteries 18650 lithium batteries, due to the stability performance of 18650 at work, widely used in major electronic fields: commonly used High-grade glare flashlight, portable power, wireless data transmitter, electric thermal warm clothing, shoes, portable instrumentation, portable lighting, portable printer, industrial instrument, medical instrument, etc. 18650 means, 18 mm in diameter, 65 mm long.

And the model of the No. 5 is 14500, 14 mm in diameter, 50 mm long. Generally, the 18650 battery is used in industrial use, very small, common, more than the laptop battery and high-end flashlight.

18650 is only the size of the battery, according to the type of battery, 18650, lithium iron phosphate 18650, 18650 (rare) of nickel-hydrogen, is a common 18650 is lithium ion. The working principle of the charging and discharge principle of the lithium-ion battery means its charging and discharge principle. When charging the battery, there is a lithium ion production on the positive electrode of the battery, and the generated lithium 18650 lithium battery 18650 lithium battery ions are moved to the negative electrode.

The carbon as an negative electrode is laminated, and there is a lot of micropores, and the lithium ions reaching the negative electrode are embedded in the microporous of the carbon layer, the more lithium ions embedded, the higher the charging capacity. The same truth, when discharging the battery (ie, the process we use the battery), the lithium ions embedded in the negative electrode carbon layer, and move back to the positive electrode. The more lithium ions returned to the positive electrode, the higher the discharge capacity.

We usually say that the battery capacity refers to the discharge capacity. It is not difficult to see that during the charge and discharge of the lithium ion battery, lithium ions are in the motion state of the positive electrode → negative electrode → positive electrode. If we compare the lithium-ion battery image as a rocking chair, the two ends of the rocking chair are the two poles of the battery, and the lithium ion is like excellent sports, run back in the rocking chair.

So, experts gave a lithium-ion battery a cute name rocking chair battery. The charging control of the charge and discharge process is divided into two phases. The first stage is constant current charging, and the charger will charge a constant current when the battery voltage is below 4.

2V. The second phase is a constant voltage charging phase. When the battery voltage reaches 4.

2V, due to the lithium battery characteristics, if the voltage is high, it will be damaged, the charger is fixed at 4.2V, and the charging current will gradually decrease, when current When it is reduced to a certain value (usually 1/10 set current), cut off the charging circuit, charging the completion indicator, charging completion. Excessive charge and discharge of lithium ion batteries will cause permanent damage to the positive and negative poles.

Excessive discharge causes collapse of the negative electrode carbon sheet structure, and the collapse can cause 18650 lithium battery charger 18650 lithium battery charger during charging, lithium ions cannot be inserted; excessive charging makes excess of lithium ions embed the negative carbon structure, resulting in moiety Lithium ions can no longer be released. Some chargers are implemented using inexpensive solutions, which is not good enough to control accuracy, which is easy to cause abnormal battery, or even damage the battery. When purchasing charger, try to choose a large brand 18650 lithium-ion battery charger, quality and after-sales guarantee, extend battery life.

Brand protection 18650 lithium-ion battery charger has four protector: short circuit protection, overcurrent protection, overvoltage protection, battery reverse protection function, etc. Overcharge protection: When the charger is overcharged to the lithium ion battery, to prevent the increase in internal pressure due to rising temperature, it is necessary to terminate the charging state. To this end, the protective device needs to monitor the battery voltage.

When it arrives at the battery overcharge, the overcharge protection is activated, and the charging is suspended. Over-discharge protection: in order to prevent the over-discharge state of the lithium ion battery, when the lithium ion battery voltage is lower than its over-discharge voltage detection point, the over-discharge protection, the discharge is activated, and the battery holds the battery in a low static current standby mode. Overcurrent and short circuit protection: When the discharge current of the lithium ion battery is too large or short-circuited, the protection device will activate overcurrent protection function.

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