A variety of household appliances are most often powered by batteries. The 18650 type battery is most suitable in this case. These are unique products that have a number of advantages. They are often used in electronic cigarettes and LED flashlights. What types there are and their characteristics can be found in this article.

18650 battery: what it is and its types

18650 type battery

The 18650 is a lithium-ion battery, similar in shape and size to a finger-type battery. The capacity of this type ranges from 1600-3600 mAh, the output voltage is 3.7 V. To better understand the features of this battery, you should compare it with a standard AAA or AA battery. Its voltage is 1.2 or 1.5 V.

Batteries of the described type are used to power equipment that requires elements with large capacity. For example, this is an electric bicycle, a portable phone charger, a laptop, a flashlight, and so on.

Note! The battery life is quite long. To prevent the device from deteriorating, its charge must be 50%. It is in this form that the product can remain for about a month. The battery should be stored in a room with a moderate temperature (too high or low readings have a detrimental effect on the device). Optimal are +15 - +17 degrees.

Many people wonder what the numbers 18650 mean. In fact, everything is very simple. The first two digits are the diameter, 65 is the length of the battery in millimeters.

There are the following types of 18650 batteries depending on the chemical indicator:

1. Lithium Manganese Oxide. These include LiMn2O4, IMR, LiNiMnCoO2, NMC, INR, LiMnO2.

2. Lithium Cobalt Oxide. These are NCR, ICR, LiCoO2 batteries.

3. Lithium Iron Phosphate or Ferrophosphate. Here we can name LFP, LiFePO4, IFR.

Owners of household appliances, when it comes time to recharge the battery, are interested in how to do it correctly. It is better to use a special device. The charger starts the process at a set voltage of 0.05 V, gradually increasing it to 4.2. The value should not rise higher, because this harms the performance of the battery.

The current strength allowed for charging should fluctuate around 0.5 - 1 A. These indicators directly affect the charging speed. If you do not need to use the battery urgently, it is better not to speed up the charging process.

It will take about 3 hours to completely replenish the product. After this time, the battery is automatically disconnected from the device. This way you don’t have to worry about the battery overheating and damaging it. If your charger does not have a charging control function, you will have to monitor the process yourself and turn it off when necessary. It is best to listen to specialists and purchase multifunctional devices with controller. This way the charging process will be the safest.

Currently purchasing charger is not a problem. A large number of devices are available in the assortment of stores and retail outlets different manufacturers and different price categories. Experts advise not to take price as the basis for your choice, but to pay special attention to the characteristics.

Types of chargers:

1. Charging with one socket and a current of no more than 1 A. These are the most inexpensive devices and will be a great help for those users who charge batteries only a few times a year.
2. Charging with two sockets creates a voltage of up to 4.2 V. These devices have a special indicator that monitors operating time.
3. Universal chargers used for batteries of different chemistry. They can be used not only for lithium, but also for nickel types.

Cost is also an important indicator when choosing a quality battery. Devices of greater cost, as a rule, have relays, controllers and indicators. Those who feel empowered and have certain technical and chemical knowledge can make chargers on their own. In this case, it is important to have knowledge regarding the functioning electrical circuit and battery parameters.

Popular 18650 battery models

Among the many options on the market, only a few are in good demand. Such products are characterized by a long service life and reliability.

Panasonic NCR18650B batteries

Let's look at the most popular battery models and their main characteristics:

• Panasonic NCR18650B – has a capacity of 3400mah. Until recently, this battery held a leading position in terms of volume among other lithium types available for free sale. The emergence of medium-current and higher-capacity batteries displaced Panasonic from first place. However, even now there are buyers for this product. As for the design of this battery, inside it there is an anode, rolled into a roll, as well as a cathode. The manufacturer placed a separator between them. All these elements are placed in a cylinder-shaped housing.
• Samsung INR18650-25R. The element capacity is 2500mah. This battery is designed to operate with high current power. If the load is continuous, then the current is 20 A, but if it is periodic, then the figure increases to 100 A. This battery is perfect for an electronic cigarette. Manufacturers recommend using Samsung INR18650-25R batteries in devices that have a built-in protection system, since they themselves do not have this function. Such products are not suitable for flashlights, as they can be over-discharged, which is unfavorable for them.

Battery Samsung INR18650-25R

• LG 18650 HE2, capacity 2500 mAh. This battery is high current. With its capacity, it can withstand a load of 8 C and provides a current of 20 A. Due to such characteristics and performance indicators, the battery model is popular and in demand. In addition, the battery also has a lot of advantages. The most important advanced indicator of the device is the latest chemical composition. It's called NCR or Hybrid IMR. This name speaks for itself: it is a hybrid of ICR and IMR batteries. The battery contains a cobalt cathode and a coating of manganese and nickel. Due to the use of such advanced technology, the battery is discharged to a low voltage, without losing its performance properties.
• Samsung ICR18650 with a capacity of 2600 mAh 26H. Such a battery has an industrial purpose and is characterized by the absence of a protection board. The battery has a high capacity, so it is often used for screwdrivers, laptops and other household appliances. Samsung are often found among repackaging companies that use them to operate their products. An acceptable price and a really large price made them the best seller among 18650 lithium-ion batteries. The positive contact of the battery is slightly recessed.

Battery Samsung ICR18650

• KeepPower, capacity 3500mah. Another high-quality 18650 battery. To create such a product, the Japanese manufacturer used a board designed to protect the battery from short circuit and recharge. The maximum current is 5 A, voltage is 3.7 V.

It is quite possible to charge batteries without harming them and maintaining their performance properties in the future, knowing the characteristics and permissible voltage and current values. The battery will last longer if you treat it with care.

Lithium ion cell 18650 test

4800mAh, 5200mAh, 6800mAh, 8800mAh in one LiIon 18650 battery!?

4800mAh, 5200mAh, 6800mAh, 8800mAh. With such “fantastic” characteristics they sell 18650 battery cells in stores in our city!
The appearance of such powerful 18650 lithium-ion battery cells on the battery cell market could not interest us. Even the leader in the production of LiIon batteries, Panasonic, which produces the NCR18650G with a capacity of 3400 mAh, looks very pale next to them. We decided to conduct a test and publish the data obtained!
Using a software and hardware complex for testing battery cells, we can emulate various operating conditions of battery cells: charging, discharging, different currents and voltages.
As with testing batteries, we also checked the LiIon 18650 3.7V battery cells for the amount of energy output and its cost. In other words, we found out which 18650 cells are profitable to buy, and which 18650 batteries have cheaper or more expensive electricity.
We tested all elements according to the following scheme:
1. Charge the battery cell to a voltage of 4.2 volts.
2. Rest the element without load and without applying voltage for 5 minutes.
3. Discharge the element to a voltage of 2.75 volts with a current of 0.5 amperes.

We purchased 1 piece of each model in different retail stores in Irkutsk:*
- HANGLIANG 18650 6800mAh - Price: 250 rub.
- BAILONG 18650 8800mAh - Price: 380 rub.
- UITRAFLRC 18650 4800mAh - Price: 250 rub.
- XBAL G 18650 8800mAh - Price: 350 rub.

For comparison, the following were used in the experiment:*
- - Price: 225 rub.
- China ISR18650P 2200mAh - Price: 280 rub.
- - Price: 300 rub.
- SAMSUNG ICR18650-24E 2400mAh used - Price: free on promotion.

Battery cell testing results
LiIon 18650 3.7 volts,
discharge up to 2.75 volts, load 500mA.

	price, rub.	Battery discharge time to 2.75 volts, hour:min:sec	Received capacity from battery, mAh	Cost of 1Ah, rub.
China ISR18650 1300mAh power	225	2:32:06	1317,59	0,17
China ISR18650P 2200mAh	280	4:25:08	2292,56	0,12
LG LGABB41865 2600mAh	300	4:57:04	2572,04	0,12
SAMSUNG ICR18650-24E 2400mAh used	free with promotion	2:52:40	1494,14	0,00
HANGLIANG 18650 6800mAh	250	0:02:49	473,00	0,53
BAILONG 18650 8800mAh	380	0:35:45	309,55	1,23
UITRAFLRC 18650 4800mAh	250	1:01:30	532,19	0,47
XBAL G 18650 8800mAh	350	1:04:12	555,78	0,63

*prices indicated at the time of writing, June 20016.

After test autopsy

During testing, we paid attention to the low weight of elements from HANGLIANG, BAILONG, UITRAFLRC and XBAL. On average, the weight of one element was only 25 grams. Typically 18650 cells weigh around 40-45 grams.
We opened one of the elements. Approximately 1/4 of the battery was free. The electrode winding is not dense and has interlayer gaps.
Thus, we can conclude that one of the signs of a battery with a fictitious capacity is the light weight of the element with a capacity indicated on it of more than 2500-3000 mAh.

With this guide, you will learn to recognize which 18650 batteries are the best in their class, how to spot a fake, and what exactly to look for in the specifications.

What is 18650?

1. What does “18650” mean in the name of the battery?

Everything is simple here - the cell size is 18 mm x 65 mm, these numbers are included in the name. If you see different numbers in a similar element, then you have reason to think about compatibility problems due to the difference in dimensions.

2. What is this 18650 battery that has become widely used?

Really, this type batteries are becoming increasingly popular due to their low cost and good practical properties. They have capacities ranging from 1800 mAh to 3500 mAh and output voltage 3.7 Volt, which is ideal for use in laptops, flashlights, electronics accessories, laser pointers and so on.

The 18650 battery provides the best performance of any consumer battery.

They are not susceptible negative influence fully charged to 100% and fully discharged (as is the case with old nickel-cadmium cells), although they will age like any lithium battery - that is, degrade at about the same rate as your smartphone battery.

Choosing the Right 18650 Battery

1. There is no single standard- you need to understand that its design differs from product to product.

2. Not all lithium ion batteries 18650 is suitable for your application- some models are aimed at industry, others at electronic cigarettes, others at gadgets, and so on.

3. The most important characteristic 18650 is the constant discharge parameter (CDR), known as amperage.

4. CDR is measured in amperes (A) and shows the rate at which current flows from the battery to the device without overheating.

5. Match CDR to Power Consumption on your device (also indicated in amps) to find out which battery is best for you.

6. If you choose the wrong battery, then the cell will overheat and quickly degrade during operation.

7. A strong discrepancy in characteristics will lead to rupture of the battery casing and fire.

8. To avoid problems, pay attention to the capacity of 18650 (mAh) - this indicator has a direct relationship with the CDR parameter.

9. The higher the capacity (mAh), the lower the CDR- that is, less powerful devices (low current levels) can use more powerful batteries 18650 (with higher capacity).

10. And vice versa However, more powerful devices (such as laptops) should use smaller 18650 batteries.

In 2019, the maximum CDR of the 18650 battery in the specifications is 38 amps at capacity 2000 mAh.

Much of what manufacturers indicate is an outright lie - CDR 40A on battery with 3000 mAh capacity is not possible on this moment. It is better to think about whether you should trust such a supplier. But in the near future, lithium-ion cells will increase in density, so the relevance of these figures may change by the beginning of 2020.

Do you really need 18650 batteries with protection?

Protected 18650 are equipped with an electronic circuit tiny sizes, which is built inside the cell and is designed to protect the element from excessive charges and discharges, as well as short circuits and overheating. Built-in protection reduces the risk of fire and damage to the electronics in which the battery is installed.

If you wanted to know which 18650 battery is better, then you should pay attention to products where, in addition to basic protection There is also a valve to relieve excessive pressure inside the battery. This occurs when the battery swells and becomes vulnerable to spontaneous combustion.

What if you already have an 18650 battery without protection?

In most situations, unprotected 18650 batteries are chosen due to low cost or the presence of an external charging process safety controller (purchased separately). Take care of such cells and keep them in optimal condition - do not discharge them to zero.

Also, after purchasing an unprotected cell, pay close attention to the discharge rating (CDR) to ensure there is no excessive power and therefore overheating. You should also keep the contacts covered - ideally in a plastic casing that will help prevent shorts in your bag or pocket. Don't leave 18650 batteries unprotected in the charger for too long.

If you are in doubt about the choice and do not understand when the 18650 does not have protection and what exactly is the difference, then it is better to overpay a little and buy a protected option.

In conclusion about 18650 batteries - how to distinguish a fake?

As with any product, you should be wary of counterfeits. Some sellers violate brand rights by labeling cheap Chinese batteries and selling them as expensive 18650 batteries. Similar cases were spotted not only on Aliexpress, but also on eBay, Amazon and even larger retail chains.

Fake 18650- this is not only a waste of your money, but also a potentially dangerous purchase! On a powerful device, cheating the CDR may result in fire or damage to the portable device.

Admittedly, it is incredibly difficult to distinguish a genuine battery from a counterfeit one. From the packaging and branding to the online ad, everything looks like the real thing.

The most effective way to identify a fake

The most accurate way to identify a fake is to determine the difference in weight. Find out from the seller the weight, capacity and maximum volume of the CDR, and then compare them with the official Datasheet (documentary specification) on the manufacturer's website.

Branded battery 18650 Samsung 30Q from our catalog weighs on average 45.6 grams, which corresponds to the official description and, as one of the criteria, confirms the authenticity of the product. This cell has a current strength (CDR) of 15A, and a capacity of 3000 mAh - this is the most versatile battery in the family.

If you have any questions, please leave a comment below or send a message to our group

Lithium-ion batteries entered our lives with cell phones And mobile devices. Until recently, lithium-ion batteries were practically not used in everyday life for other autonomous devices; the main power source for such devices is nickel-metal hydride batteries of the usual sizes AAA, AA, C, D.

Now they are gradually being replaced by lithium-based batteries, as their operational advantages have become undeniable.

• Very low self-discharge. Energy losses are minimal when used correctly.
• High energy density, correspondingly higher energy capacity without increasing the size compared to similar nickel batteries.
• More high voltage at the exit. In comparison, the minimum for lithium is 3.6 Volts with a standard nickel 1.2 Volt for the same size.
• Reducing battery weight while maintaining dimensions.
• Increased number of discharge-charge cycles while maintaining performance.
• A slight decrease in performance due to loss of energy capacity after numerous discharge-charge cycles.

Given these benefits, an increasing number of professional users are converting their stand-alone devices to cylindrical lithium-ion batteries and assemblies of them. At the same time, not everyone knows how to properly use, maintain, and store new power sources. And also select them by size and current parameters.

The designation of the sizes of cylindrical lithium-ion batteries differs from those usual for all nickel batteries - it is digital, for example, 14500 or 18650. This coding is unusual, but it is convenient for selecting the required battery according to the slot size of the electronic device. The first two digits of the code indicate the diameter of the battery in millimeters, the second - its height. For example, size 18650: 18mm diameter, 65mm height.

Rules for the operation of lithium-ion batteries and assemblies

Lithium-ion batteries are both reliable and capricious, which at first glance seems like a paradox. They are fastidious in storage, maintenance and operation. If the conditions of use are violated, they quickly fail. But if all the rules are followed, they last a long time with high performance.

Main restrictions:

• The minimum voltage for lithium-ion batteries should not be less than 2.2-2.5 Volts.
• The maximum voltage for lithium-ion batteries should not be more than 4.25-4.35 Volts.
• Lithium-ion batteries work well at sub-zero temperatures, but they cannot be charged in the cold, especially if the temperature is below zero degrees.
• The charging current of lithium-ion batteries should not exceed half their capacity. For example, for a 2000mAh battery, the maximum charge current should be 900-1000 mA.
• The discharge current (operating) should not be higher than 2 times the battery capacity. For example, for a battery with a capacity of 2000 mAh, the maximum discharge current is 4000 mA.
• Exceptions are high-power lithium-ion batteries, the discharge current of which can exceed their energy capacity by 5-10 times. Such batteries are marked with the appropriate inscription.

Cylindrical lithium-ion batteries are often used for large battery assemblies. Battery assemblies have higher power and a longer cycle life. Such battery assemblies are used in high-power devices. This is what the lithium-ion battery of a powerful screwdriver or drill looks like.

When assembling a battery yourself, you should remember that lithium-ion batteries do not tolerate overheating, so you CANNOT SOLDER them! Such a battery assembly will not work, since we can say with confidence that soldering the contacts has damaged the batteries.

When assembling the battery, a special welding tape and resistance welding.

For safe work batteries needed charge-discharge controller.

During assembly batteries are used only unprotected lithium-ion batteries! Using them, you can assemble a large, very energy-intensive battery (rechargeable battery), which can be used in powerful electrical appliances and serve as an additional power source.

Such batteries are found in electric drills, screwdrivers, spotlights, photo and video equipment, laptops, monitors, etc. with the mandatory addition of protection against overvoltage, overheating and short circuit in the form of a controller board.

Protected or unprotected lithium-ion batteries

What are the differences and which one should you choose? – the main question of concern to the average user. The answer is in the name: protected ones have their own overheating and overvoltage protection board and do not need an additional charge-discharge controller.

If you want to build your own lithium-ion battery or replace the battery in an off-the-shelf electrical device battery (such as a screwdriver), you need an unprotected lithium-ion battery.

In other cases - when replacing the original batteries of devices or converting them from nickel-metal hydride to lithium - it is necessary buy protected lithium-ion battery.

If we open the shell of a protected lithium-ion battery, then under it we will find a regular unprotected one with the same parameters as indicated on the outer shell.

The main difference between a protected battery and an unprotected one is the electronic protection board welded to one of the contacts.

The protection board is welded to one of the contacts of an unprotected lithium-ion battery using welding tape.

Then everything is packaged in film with the markings of the manufacturer of the protected batteries. Conscientious manufacturers indicate on the outer packaging the manufacturer of the unprotected battery used and the parameters in accordance with the labeling of the unprotected battery.

When choosing a protected battery for your device, there is one very important thing to consider: important point. Due to the welded protection board and film packaging, the size of the battery becomes slightly larger than the declared, original size of the unprotected battery.

The height increases by 3-5mm.

The diameter becomes larger by about 0.5 mm.

When choosing a protected battery, you need to inquire about the manufacturer of the unprotected one. Unfortunately, not all manufacturers indicate it on the packaging, although they often use unprotected batteries that are not of their own production. For example, they weld protection and package unprotected batteries from well-known brands Panasonic, Sony, Samsung and others. You should not buy protected batteries if all the parameters of the “filling” are not indicated on them: energy capacity, voltage, protection board. It is worth checking the protected batteries by touch to see if the protection board on the positive contact moves when pressed; it must be welded.

Cylindrical lithium-ion batteries can only be charged with special chargers. Due to the popularization of lithium-ion batteries, the range of chargers for Li-Ion is growing. When choosing a charger, you need to pay attention to its charge-discharge parameters, the size of the slots and correlate them with the lithium-ion batteries used for proper operation and preservation of functionality.

To answer the question of what the 18650 format battery is used for or what it is also called - 168A, let's study its characteristics and capabilities, as well as examples of use in domestic conditions.

This type of battery is currently quite popular for a number of reasons, but the main ones are the voltage of 3.7-4.3 volts and good capacity (running time) up to 3600 mAh, as well as a fairly compact size.

They are similar in shape to AA-sized “finger” batteries and AAA-sized “pinky” batteries, but larger in size. As mentioned above, the output voltage of these batteries is 3.7 - 4.3V. Capacity is 2200-3400 mAh.

AA and AAA AA batteries have a voltage of 1.5V

At Ni-MH ( nickel-metal hydride) batteries of AA and AAA format - 1.2V.

Schematic device of a Li-ion battery

Li-ion battery capacity 18650

Energy capacity is the amount of energy that is stored in the battery. Battery capacity is often expressed in watt-hours (Wh), kilowatt-hours (kWh) or ampere-hours (Ah). The most common measure of battery capacity is Ah, defined as the number of hours that the battery can supply a current equal to the discharge rate at the battery's rated voltage. A watt hour is the voltage (V) that the battery provides multiplied by the amount of current (amps) the battery can provide for some time (usually in hours). Voltage*Ampere*hours = Wh. Since the voltage is highly dependent on the battery type due to its internal chemistry (alkaline, lithium, lead acid, etc.), often the battery side only displays amp hour data expressed in Ah or mAh (1000 mAh = 1 Ah). To get Wh, multiply Ah by the rated voltage. For example, suppose we have a nominal 3 V battery with a capacity of 1 Ah or 1000 mA*h, its power will be 3 W.

1 A*h means that theoretically we can use 1 ampere of current for one hour or 0.1A for 10 hours or 0.01A (10 mA) for 100 hours.

IMPORTANT! At the time of writing, there are NO batteries with a capacity higher than 3600 mAh in the 18650 size!!!

Battery size 18650

Decoding the digital designations of the 18650 battery:

the first two digits (18) – diameter;

the next pair of numbers (65) is the length;

the last digit (0) indicates the shape of the battery, in this case a cylinder.

As we can see after measurements, the length of the cheapest Chinese battery brand UltraFire (manufacturer of cheap Chinese flashlights) 18650 format is 66.5mm, and the diameter is 18mm.

Let's compare the sizes with other types of batteries:

AAA: 44.5 x 10.5 mm

AA: 50.5 x 14.5 mm

14500: 53 x 14.5 mm

18650: 65.5 x 18 mm (unprotected)

18650: 67.5 x 18 mm (protected)

26650: 67.5 x 26.1 mm

A visual comparison of AA, AAA and 18650 batteries.

And although the 18650 format battery resembles finger and little finger batteries, it will be larger in size.

What is a protected battery

18650 batteries come with and without protection - if the 18650 battery does not have protection, then there are no additional inscriptions on it, or the inscription “Unprotected” is present. The length of the unprotected one (without a protection board against complete discharge or overcharge) is 66.5 mm.

If the battery description contains the words “With Re/Discharging Protection Circuit” (protection from complete discharge/overcharge), “Protected”, “With protective PCB”, “Protection Circuit”, etc., then the battery has a protection board on board. A small thickening (usually a 1mm plate) near the contact is the battery protection board.

For reliable operation and to avoid damage, complete discharge or overcharging and overheating, Li-Ion batteries must operate within a voltage range of 4.2-2.5V.

One of the weak points Li-ion batteries is that they are in the process of overcharging and/or overheating, as well as when they are completely discharged, they are susceptible to failure. After which it will be problematic to restore or charge the battery or it will lose its initial capacity. If handled carelessly, lithium-ion batteries can fail more often than other types of batteries.

This problem is solved, as noted above, by installing electronic circuit protection that prevents excessive overcharging and/or overheating as a result of exceeding the permissible current during charging, and also interrupts the circuit when the charge is low, protecting the battery from deep discharge during operation. This protection board not only ensures that the battery operates within the safe voltage range, but also prevents overcurrent and short circuits. The protection board is spot welded using a steel conductor to the corresponding battery contacts. In reality, it looks like this: an electronic protection board with a thickness of 1-3mm and the diameter of the battery is installed on the negative contact of an unprotected Li-Ion battery (“cell”).

The length of such a battery is slightly longer - on average 67.5-70mm versus 65-66mm for an unprotected one. When the battery voltage rises above 4.25V, the protection board blocks further charging of the battery to prevent it from being damaged by overcharging and overheating. The same thing happens when the voltage is less than 2.75V - the protection board blocks further discharge of the battery below the specified threshold.

Typically, large Li-Ion battery manufacturers do not produce batteries with built-in protection. They only produce unprotected batteries. As a rule, there are no protected Li-Ion batteries of the SAMSUNG or Panasonic brand, which would be released specifically by “Panasonic in Japan” or “Samsung in Korea”, and those who prove the opposite are intentionally or unintentionally trying to mislead you misleading.

Protected batteries are assembled from conventional Li-Ion batteries (cells) followed by installation of a protection board.

The assembly process can occur in different ways: as a rule, the battery assembly with protection is carried out at enterprises in China. But China is different - there are both outright counterfeits and amateurism on the part of little-known battery manufacturers (with imaginary capacities from 3800 mAh to infinity) and very high-quality products from well-known brands.

Protected batteries are assembled and sold by completely different brands that are not related to the manufacturer of the batteries themselves. A factory-assembled battery with protection is covered with a thermal shell with the brand name and an indication of the capacity (sometimes real and sometimes absolutely fantastic).

Due to the fact that a protected 18650 battery is 1-3 millimeters longer than its unprotected counterparts and sometimes 0.5 mm thicker in diameter.

Extended batteries with protection may have a standard size of 18700, and size always matters - such a battery may not fit into the battery compartment of some consumer devices. Therefore, when choosing a protected battery, you should think about whether it is suitable in length, for example, for your LED flashlight, charger, etc.

Mechanical - internal protection of Li-ion batteries

In addition to protection using a charge controller board, the battery can use an internal mechanical protection system for the battery. The internal protection function is to trigger a special mechanical switch as a result of the temperature threshold (overcharge/heating) and pressure inside the battery increasing to critical values, which can lead to an explosion. The battery is disconnected by mechanically breaking the circuit by the internal protection of the power source. If this does not help and the temperature and pressure continue to rise further, then the pressure relief valve is activated, which releases gases and electrolyte outside.

The mechanical switch itself is quite common as a primary or additional safety measure in many batteries, functioning in conjunction with or without a charge controller (board). It is worth noting that the presence of internal protection will not necessarily be mentioned on the case or in the description technical characteristics products. As a rule, well-known manufacturing companies will not neglect the internal mechanical protection of their power supplies with an unstable chemical composition, with the possible exception of the cheapest and little-known Chinese brands. Therefore, regardless of whether any power supply has or does not have an electronic protection board, it must have built-in physical protection.

Use of protected and unprotected Li-ion batteries

18650 batteries are usually used where long periods of time are required. battery life with a compact size.

Both unprotected and protected batteries can be used in any devices or devices designed to work with Li-Ion power sources, the only difference is that if the device or device do not have a built-in charge-discharge controller, then this disadvantage can be compensated for by a protected power supply.

The main devices that use Li-Ion batteries today are LED flashlights and lamps, since these batteries have sufficient power and capacity to ensure long-term and uninterrupted operation of powerful LEDs last generations in these devices.

In our particular example, these are LED lights with diodes of the latest generations XM-L/L2, XP-L/L2, etc. (Convoy s2+, Convoy c8).

This flashlight contains AAA battery

This flashlight runs on AA battery

And these lights are equipped with the latest generations of LEDs CREE XM-L2, XP-L2. They require a lot of power to operate. That is why these flashlights are powered by an 18650 battery and are made for it, as it is ideal for these purposes.

Some flashlights from cheap Chinese brands such as UltraFire are designed in such a way that the 18650 battery can be replaced with 3 AA batteries through a special adapter. In this case, the voltage is almost the same: 3.7V and 4.5V (= 1.25V*3 or 1.5V*3).

In most cases for simple Chinese LED lights UltraFire type, requires a protected battery.

It happens that some batteries have too sensitive current protection and operate at less than permissible values. In this regard, the lights on powerful LEDs latest generations XM-L/L2, XP-L/L2 do not function properly. When you turn on the flashlight, an overcurrent occurs - the battery protection is triggered, the flashlight may blink and no longer show signs of life. If you change the battery to an identical one, the same thing can happen; the protection is triggered instantly. There are two options - either remove the protection board and use the battery without it, or replace the battery with another one from a time-tested brand.

As mentioned above, battery protection definitely increases the length of the battery by 1-2 mm, or even more. If the Li-Ion battery with protection reaches a length of 7 cm, some compact flashlights designed to install Li-Ion batteries cannot be screwed in back cover and you have to look for a battery without protection or remove it again. The longer the battery, the greater the force of the springs on it in the battery compartment; it happens that they push through the negative contact of the Li-Ion battery. Most often this happens when the flashlight is used as an under-barrel flashlight during recoil during a shot. And it’s not very pleasant to push such a battery into the battery compartment of the flashlight by forcefully twisting the lid, scratching and damaging the battery contact with the spring.
But no matter what the battery protection is, it does not 100% guarantee the safety of the battery and flashlight from overheating and even explosion.

Usually, the increased pressure in the battery is released through special holes in the battery valve, but in the sealed space of the flashlight they may not help.

In principle, if you know the approximate effective operating time of a Li-Ion battery based on its capacity in a particular consumer, then you can safely use unprotected batteries. Many people do this. This applies to flashlights with a single battery. If several batteries are used, protection must be required.

It happens that the protection board fails. To restore further use of the battery without it, do the following:

Remove the polymer coating (shell);

On the case you can see the positive conductor going to the protection board, which is simultaneously spot welded to the battery case (minus). In case of critical current and voltage values, the protection board breaks this circuit;

The protection board is removed, freeing from spot welding. Remove the conductor;

Remove the sheath around the negative terminal so that the contact is accessible for connection to the final consumer devices;

Instead of the original shell, you can use ordinary adhesive tape or electrical tape or self-adhesive film of any color, cutting a piece out of it to the size of the battery and carefully covering it with it. With such a film, the battery will become unique, especially if you wrap it in carbon film. :-)

After removing the protection board, the battery will lose 1-3 mm in length. And it will become regular battery without protection.

If, for example, you need to repair the battery in a laptop, upgrade the battery in a screwdriver, or you need a prefabricated BATTERY from Li-Ion batteries, then for this you need to use unprotected batteries.

Pros and cons of lithium-ion batteries

Typically a 18650 battery is li-ion-th battery.

The main advantages of Li-ion batteries are:

High energy density;

Higher voltage (compared to NiCd and NiMH batteries);

Low self-discharge 4–6% per month, 10–20% per year;

No “memory effect”, no need for “training” after purchase - there is no need to fully charge and then completely discharge lithium batteries after purchase;

Wide operating temperature range – from -20 to + 50 °C;

Long service life of about 10 years;

Significant reserve of discharge-charge operating cycles of more than 1000;

Ease of maintenance;

Low specific gravity.

A few disadvantages of Li-ion batteries:

Relatively expensive (every day this minus disappears);

Low resistance to overcharge and complete discharge, which is why smart Li-Ion batteries are equipped with built-in automatic shutdown systems;

Unlimited range of operating temperatures (from -20 to + 50 C), deterioration of performance at high temperatures, reduction in capacity when used in cold weather;

Difficulty charging at low temperatures;

Explosion hazard if the housing is damaged, punctured or otherwise sealed;

Dependence of service life on time, and not on the number of discharge and charge cycles, over time there is a gradual loss of capacity

Storing lithium polymer and lithium ion batteries

Lithium polymer and lithium ion batteries lose capacity when charged, unlike nickel and nickel metal hydride batteries. The higher the battery charge and the temperature during its storage, the shorter its service life. Overcharging, like overdischarging, “burns out” the battery capacity.

The optimal storage conditions for Li-ion batteries are:

• 40-50% charge of battery capacity;
• temperature 0-10 degrees Celsius.

At the same time, low temperature is a more important factor for small losses of capacity during long-term storage. The average shelf life (service) of a lithium battery is on average 36 months. Lithium batteries age even when not used.
(Wikipedia).

To extend service life lithium battery and improve its efficiency, you need to follow simple recommendations:

Avoid completely discharging the battery, recharge it regularly when the charge level drops to 20%;

do not allow the battery to overheat or expose it to direct sunlight;

Do not use the battery in severe frost; insulate it for use in winter;

store the lithium-ion battery with a 50% charge level, at a temperature of 0 C;

protect the battery from shock, damage and strong vibration; when installing it on electric vehicles, use a soft layer

Deciphering markings and inscriptions on batteries

In mass production, three classes of Li-ion batteries are used (based on the cathode material, the second letter in the marking):
1) lithium-cobalt LiCoO2 (the most common, the highest capacity among Li-Ion)
2) lithium-manganese LiMnO2, LiMn2O4, LiNiMnCoO2 (better known as high-current (INR), capable of delivering currents of 5-7C to the load, which are usually inferior in capacity to the former)
3) lithium ferrophosphate LiFePO4 (excellent batteries undervalued by the market, in all respects they undoubtedly outperform the first two types, except for operating voltage and capacity, it is even lower than that of INR)
As they say, all three classes are tailored to perform specific tasks and have their pros and cons.

Since there are no uniform battery labeling standards, all manufacturers label them differently. But ideally it should be something like this:
1) the first letter is the manufacturing technology (I - lithium-ion technology)
2) second letter - type of chemistry, cathode material (C/M/F - cobalt/manganese/iron phosphate chemistry)
3) third letter R - battery (rechargeable)
4) five digits - form factor (the first two digits are diameter, the next two are length, the last digit is the shape of the acca (0 - cylindrical))
- 10440 (everyone’s familiar “little fingers”)
- 14500 (everyone’s familiar “fingers”),
- 16340 (size like a CR123 battery),
- 17335 (not common)
- 18500 (also not very common)
- 18650 (the most common form factor on the market),
- 18700 (unofficially, 18650 battery + protection board, i.e. protected battery),
- 26650 (enlarged, came to the market from the company A123 Systems, which produces lithium ferrophosphate batteries)
- 32650 (absolutely monsters, only for stationary devices, weight almost 150g)
- plus unofficial f/f with protection boards, for example 18670...
5) letters/numbers - specific marking of the container (different for all manufacturers)

An example of marking, but as a rule, it is different for all manufacturers:
- Samsung ICR18650-26F (lithium-ion battery with the usual cobalt chemistry, f/f 18650 with a capacity of 2600mah)
- Samsung INR18650-20R (lithium-ion battery with manganese chemistry, i.e. high-current, f/f 18650 with a capacity of 2000mah)

Own designations:
Panasonic NCR18650PF (NCR is a type of cobalt chemistry, something between the first and second class, i.e. in simple words chemistry LiNiCoO2, without the use of maranz. No matter how it fits a certain class, it turns out to be a kind of symbiosis. Among the advantages - high density energy with low thresholds up to 2.5-2.75V). This battery uses LiNiMnCoO2 chemistry, that is, it is already IMR high-current based on manganese, but the manufacturer left the old markings.
Sanyo UR18650FM – the information may not be accurate, but I came across information that Sanyo does not produce batteries for retail sale, and therefore does not bother with labeling. It produces cans for large electronics manufacturers, so the labeling is purely “for itself.” Perhaps, according to the company's internal designations, UR and F(M) stand for type, chemistry and capacity, according to at least There is no information in the datasheets (only that this is the model marking). And this is a lithium-ion battery with the usual cobalt chemistry, f/f 18650 with a capacity of 2600mah.

Selecting a 18650 battery

Now, after we have studied the main characteristics of batteries, let’s try to figure out how not to make a mistake when buying a battery and what type to choose for specific tasks. Many of us use flashlights and lamps with 18650 batteries, and some also have power banks for these types of batteries.
You should never take the word for the inscriptions on batteries of unknown, little-known or cheap brands.

A clear example of a battery with fantastic capacity

A person who doesn’t understand will immediately fall for it - that’s a fact. Be carefull!

Choosing a 18650 battery. Questions and Answers

If you need simple advice - which 18650 battery is better to buy without delving headlong into the technical component, “so that it just works normally”, we will answer this:

The most affordable in terms of price/quality ratio is the Samsung ICR18650-26F (or H) with a capacity of 2600mAh; most of your devices and flashlights will work on it without problems.

If you increase the cost budget for purchasing a battery by one and a half to two times, you can purchase an almost maximum capacity battery LG18650MJ1 (30% more):

Its analogues are Sanyo (NCR18650GA) and Samsung (INR18650-35E), and Samsung is noticeably cheaper.

If you need a record holder for capacity and quality, then this is definitely what we think at the moment: Panasonic NCR18650G 3600mAh

Protected and/or unprotected 18650 battery?

Attention! All items on this list are required!

We are talking about electronic protection from overcharge, overdischarge and short circuit. Details with pictures.

Batteries with protection must

• The lantern consists of two or more sequentially installed batteries. "Lantern-baton", like this.
• You are using a simple charger without an overcharge protection circuit and/or from little-known Chinese manufacturers.
• The flashlight is equipped with mechanical protection against polarity reversal of an incorrectly installed battery. For this, a battery with protection with a protruding positive contact is usually used (exceptions are possible, of course).
• The flashlight does not provide information or shutdown protection when the battery is significantly discharged - below 2.6 V, and you don’t want to bother with this (you can simply forget to turn it off).
• The flashlight may fall into the temporary use of forgetful and/or inexperienced people, as well as into the hands of your children and they will torture it until they lose their “pulse”).

Batteries with protection Can

• For flashlights powered by 18650 size batteries, if the protected battery fits freely into it in length (there are no problems with screwing the battery compartment cover) and in diameter (does not rest against the walls during installation).
• Powerful flashlight with parallel connecting two or more batteries. In our opinion, this is a controversial decision.

Unprotected batteries must used in the following cases:

• The battery compartment is too narrow or short in a flashlight designed for one 18650 battery(important!) (impossibility of installing a protected battery that is 2-3mm longer and 0.5mm wider).
• As a rule, a modern flashlight with powerful LEDs (xm-l2 xp-l2) powered by one The battery consumes a lot of current at maximum brightness (3 amps or more). And many protected batteries may simply shut down when turned on due to overcurrent.

Unprotected batteries Can use in the following cases:

1. The flashlight is designed for one battery or it runs on two or more parallel installed batteries.
2. A smart charger is used (smooth reduction of the battery charging current and the function of automatically turning off the battery after charging, selection of charging current, other functions) from trusted brands (liitokala, nitecore)
3. You will never forget to turn off the flashlight after use and/or will not leave it on for long periods of time unattended (unless it has built-in low battery protection).
4. Children do not have access to the Lantern and/or you do not trust others to use it without your presence.
5. You store batteries in a special box and do not throw them anywhere, due to which they can be accidentally shorted by metal objects or random current conductors.

Branded and/or Chinese battery size 18650?

Previously, purchasing a cheap Chinese (from a true Chinese brand) 18650 battery was justified. Several years ago, such batteries were much cheaper than branded ones, and in terms of characteristics they were close to their branded counterparts.
But time goes by. And starting from 13-14, some well-known brands, in order not to be left out, reduced the price so much that purchasing a “folk” battery from China of dubious quality in order to save money became irrelevant.
In 15-16 years, super-capacious batteries - one might say the flagships Panasonic 3600, due to fierce competition from Korean brands, reduced the price almost to the level of what had become popular at that time - Samsung.

Therefore, to the Chinese brand - manufacturer of 18650 batteries (Even if it is already quite popular) we can say: who are you? let's goodbye.

When choosing a battery, do not forget about this:

• There are only four main manufacturers of 18650 batteries from well-known brands: Panasonic, Sanyo, Samsung and LG. There is also Sony with its exotic models, but the ones mentioned above are the most common.
• All other brands (usually manufacturers of various flashlights) wrap the same Panasonic, Sanyo, Samsung and LG in thermal covers with the names and logos of their brand, well, maybe even providing these batteries with a protection board and/or modified contact pads.
• As a rule, after this they receive a noticeable increase in price, although they are no better in terms of characteristics.
• It’s true that it’s worth noting that sometimes such modified batteries can be better than their donors, since they should work without problems with flashlights from the manufacturer of the same brand (with others there may be problems due to size, contacts and current overloads).
• For some “special” flashlights, you need to purchase batteries that are recommended by the manufacturer or specified in the description/instructions for the flashlight.

Selection of capacity18650 battery

At the time of writing, large capacity according to real measurements has only one type of battery: Panasonic NCR18650G 3600mAh. What is more (there are fantastic inscriptions 4000, 5200, 9800 and even 12000!), and sometimes even quite real ones from little-known/unknown Chinese brands in fact black marketing and blatant lies our Chinese “friends” of underground production. Usually, bright labels and super inscriptions are used to hide the “pig in a poke.” On the fonarevka.ru forum, read the article Horrors of our town. In the best case, you will get working junk with a capacity of 1800-2000 mAh and a lifespan of six months to a year.

But even a branded battery with a really high capacity is not a panacea. It happens. that the operating time of the flashlight does not always increase noticeably with the installation of a high-capacity battery, and there are reasons for this. In everyday living conditions, it is quite possible to cope with the assigned tasks samsung battery capacity 2600 mAh. This workhorse By affordable price for any conditions. If you are still leaning towards batteries of higher capacity (2800, 3200, 3400 and 3600mAh), adhere to the following rules:

• Purchase batteries only from well-known brands and manufacturers.
• Popular Panasonic Li-ion batteries are capable of delivering their full capacity when discharged to 2.5 v. The truth is worth noting. that not all flashlights and powerbanks are capable of working with such low voltage. All “baton flashlights” (with 2-3 18650 batteries installed in series) and flashlights of high-quality Chinese and other brands (Convoy, etc.) running on a single 18650 battery can cope with this.
• If you use high-capacity batteries from LG or Samsung, then they need to be recharged to their operating non-standard voltage of 4.35V (the standard voltage is 4.2V), most likely using an expensive “smart” charger. An example of such a battery is the LG ICR18650E1 with a capacity of 3200mAh.
• The LG INR18650-MJ1 battery with an announced capacity of 3500mAh is physically capable of working for a long time and quietly delivering high current to the load. Moreover, its operation is carried out in the range of standard voltages of 4.2 - 3.0V Li-ion batteries. Analogues of this battery are: Sanyo (NCR18650GA); Samsung (INR18650-35E).

From all of the above, we can assume that if any of these operating conditions for more capacious and expensive batteries are violated or not met, you will most likely get the same effect from their use and operating time as from the cheaper Samsung 2600. Be that as it may from the most capacious and most expensive ones, in an ideal situation and luck - it will shine only 10-30 percent longer than usual!

Approximate price V Chinese online stores at the time of writing this article is $2-2.5 for one can of Samsung 2600mAh and $4-6 for a can of the most capacious Panasonic 3400mAh - 3600mAh. Good, high-quality protection will add another 1-3 dollars. You will have to pay a few more dollars for a beautiful wrapper from the lantern manufacturer.

The meaning of the inscriptions in English in the description of the battery 18650

• The battery capacity is designated " mAh". mAh – milli-Ampere-hour translated into Russian, as you may have guessed.
• Batteries with protection are marked " With protective PCB", "Protected", "Protection Circuit" and so on..
• Nothing is indicated about those who are not protected, or in rare cases they are indicated " Unprotected".
• Numbers indicating voltage 3.6V and 3.7V essentially mean absolutely the same thing. Represents the average voltage for a battery that needs to be charged to 4.2V. As a rule, the manufacturer decides for himself whether to indicate one or the other value.
• If the voltage is indicated on the label or in the description 3.8V then this means that the battery should be charged to non-standard 4.3 or 4.35 Volt.
• Voltage value 3.2 V usually denoted Lithium iron phosphate battery . If you haven’t heard of this and don’t know what its purpose is, just forget about it, most likely you won’t need it.

Cases of counterfeit 18650 batteries

There have been almost no cases of counterfeit batteries from the main brands: Samsung, Sanyo, LG and Panasonic. But with other brands you need to be more careful - the situation may be different.

Attention! There were cases of sales unscrupulous sellers old, worn-out batteries from dismantling large batteries from electric cars or electric bicycles.

You can determine the manufacturing date using the manufacturer's code on 18650 batteries using this link:
https://batterybro.com/18650-date

Suitable for:
Samsung
Sony
Panasonic
Sanyo
LG

Signs of such batteries:

• Remnants of removed resistance welding on the poles (scratch spots on the ends)
• Remains of sealant (glue) on the battery case

Applications

Table of characteristics for famous brands

			Marking	Charge voltage	final voltage	discharge current A continuous (maximum)
						6.4-2C(10-3C)
						6.4-2C(10-3C)

	Manufacturer		Marking

Materials used in the article

P.S. I’ll add on my own behalf as a person who has been using this type of battery for a long time - Take Liitokala, Sanyo, LG, Samsung or Panasonic!

DO NOT TAKE UltraFire or worse, especially with a capacity above 3000mAh