home > Excel > Castration of protected Sanyo and Panasonic batteries and a small educational program on Li-ion. Castration of protected Sanyo and Panasonic batteries and a small educational program on Li-ion Li-ion battery 18650 1 piece


Castration of protected Sanyo and Panasonic batteries and a small educational program on Li-ion. Castration of protected Sanyo and Panasonic batteries and a small educational program on Li-ion Li-ion battery 18650 1 piece




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Various wireless devices occupy an increasing place in everyday life: portable and easy-to-use cordless drills; laptops that allow you to work for a long time without using an electrical network.

All this makes our daily life more convenient and easier.

But a special place is occupied by the use of autonomous battery devices not near the house, where you can always charge the device, but far from power sources.

On a camping trip, hunting or fishing, the most necessary, and sometimes irreplaceable, electrical device is a flashlight. Modern flashlights equipped with LEDs have a huge number of advantages.

But the main characteristic of any electric flashlight, of course, is the duration of its operation. For tourists who go on multi-day trips, it is the duration of the flashlight that is of great importance when choosing.

And this characteristic directly depends on the type of battery that comes with the flashlight.

The compactness and lightness of equipment plays an important role for any tourist. Therefore, important characteristics for batteries are size and weight - the smaller the better.

At the same time, the batteries must have a large capacity, which will ensure long and uninterrupted operation of the flashlight, often the main source of light in the dark.

Modern technologies make it possible to combine small size and weight with high battery capacity.

One of the most common batteries for LED flashlights are 18650 batteries. These compact batteries with a relatively large capacity are best suited for modern light sources, often used by tourists, fishermen and hunters.

Main features of 18650 batteries

The name itself indicates the dimensions of the battery - 18 millimeters in diameter, 65 millimeters in length. Despite the fact that they look similar in appearance to the AA-size batteries that many are familiar with (the so-called “pen-type” batteries), 18650 batteries are larger in size.

In addition, a distinctive feature of 18650 batteries is the voltage, which at the output is 3.7 V, versus 1.5 V for smaller batteries. The capacity of 18650 batteries varies: from 1600 to 3600 mAh. It is necessary to pay attention to the fact that the capacity of a high-quality battery cannot exceed 3600 mAh.

Batteries can be used in flashlights either individually or in a Power Bank system - a device that combines several identical batteries.

One of the main qualities and advantages of batteries is the absence of memory effect and extremely low level of self-discharge.

18650 batteries can withstand up to 1000 charge/discharge cycles, which is a very good indicator for portable batteries.

Gradually, the battery charge life decreases, but with the help of special technical devices, the capacity can be restored; the only condition for restoration is the absence of mechanical damage to the battery.

  • It must be taken into account that in order to use the battery resource more rationally, you should not completely discharge it.
  • It is optimal to recharge the battery when the capacity is reduced to 40% of the nominal value. If used properly, the battery will serve reliably for a long time.

To charge 18650 batteries, you will need a special charger that is suitable for all types of batteries of this size. For example, the ARE-X1 Fenix ​​Charger, the i1 NiteCore Charger, or the Robiton SmartCharger Pro Charger.

Types of 18650 batteries

The batteries themselves, while generally similar in technical characteristics, have different contents depending on the type of cathode material. Despite the fact that they are all labeled lithium-ion batteries, there are three types:

  • 1) lithium-cobalt (LiCoO2) - the most common batteries, characterized by the highest capacity among lithium-ion batteries;
  • 2) lithium-manganese (LiMnO2, LiMn2O4, LiNiMnCoO2) - better known as high-current batteries (INR), capable of delivering currents of 5-7C to the load, but usually inferior in capacity to lithium-cobalt batteries;
  • 3) lithium ferrophosphate (LiFePO4) batteries - in all respects they undoubtedly outperform the first two types, except for operating voltage and capacity.

Each of these types has its own advantages and disadvantages and is designed to solve specific problems. They differ mainly in capacity and discharge rate.

When choosing an 18650 battery in a store, all information about it can usually be read on the battery case. The most responsible manufacturers always label their batteries.

Therefore, the presence of technical characteristics on the case is a kind of indicator of the quality of the product. There is no universal or single labeling system.

However, the following principle is most often used.

Latin letters are used in markings in different combinations. For example: the letter I - indicates that the battery is lithium-ion, with all the characteristics inherent in such batteries.

The letter R means that you have a battery in your hands that can be recharged if necessary. The letters C/M/F indicate the cathode material - cobalt, manganese or iron phosphate, respectively.

Combinations of letters can be arbitrary, but at the same time, the standard size 18650 (length and diameter) and the capacity in ampere hours are always indicated - from 1000 to 3600.

Rules for using 18650 batteries

Despite their many advantages, 18650 batteries have one drawback associated with their design. Batteries often fail quickly if they are overcharged or overheated.

  1. Overcharging causes the battery to heat up, causing the battery to catch fire or explode.
  2. Manufacturers have provided an option to protect batteries from overheating.
  3. When using 18650 batteries in a Power Bank, when connected in series, an electronic board is installed in the circuit, which limits the charge of the entire device to a given capacity.
  4. For 18650 batteries, used, for example, in flashlights, an individual system of protection against overcharging and subsequent overheating is used.

The protection is a small electronic protective board that is installed on the negative terminal of an unprotected lithium-ion battery and welded to the case with steel tape.

This prevents not only overheating, but also a short circuit, which can damage not only the battery, but also the charger. The entire structure is packed in thermal film.

Protected and unprotected 18650 batteries also have their own markings, for example: protected, with protected PCB, protection circuit - on protected batteries, unprotected - on unprotected ones.

It is necessary to pay attention to the fact that large manufacturers do not produce protected batteries, but protection is installed by companies that modify them.

Thus, protected batteries are produced under various brands, the number of which is very large.

It should be noted that after installing the protection, the length of the 18650 battery increases by about 3-4 mm, which can cause its own difficulties. Often, a longer battery does not fit into the regular place both in the flashlight and in the charger.

It is necessary to take into account that the contact spring of the flashlight or charger presses on the battery of increased length with greater force, and this can lead to pushing through the negative contact and breakdown of the battery.

Therefore, when purchasing 18650 batteries, you need to check whether they fit your flashlight or charger. However, there are also flashlights and chargers whose manufacturers immediately provide for an increased battery size.

In this case, there are no problems with installation and operation, but unprotected batteries are not suitable for such devices.

Batteries that have protection can be used in any devices operating on lithium-ion power sources that do not have a built-in charge-discharge controller.

  • It is, of course, possible to use unprotected batteries, but in this case it is necessary to control the charge level when recharging.
  • A special place in the operation of 18650 batteries is played by their proper storage.
  • Batteries should be stored in a case or box and not come into contact with metal products during storage.
  • The optimal storage temperature is from +5 to +15 degrees Celsius. Proper storage will increase the life of batteries, but the best guarantee of their longevity is constant operation.

Lithium-ion batteries gradually lose capacity and, accordingly, service life during long-term storage.

Devices powered by 18650 batteries

18650 size batteries are widely used in everyday life.

  1. Nowadays, one of the most common devices powered by 18650 batteries are high-power LED lights.
  2. These batteries are capable of powering high-power LEDs.
  3. The high capacity of the batteries allows the flashlight to work for a long time without recharging. This is especially important on long hikes. The LED flashlight will require a battery equipped with a protection board.
  4. When using an unprotected battery, constant monitoring of its operation is necessary.

Another large group of devices that use these batteries are hand-held cordless drills, which for short are called screwdrivers.

These essential tools for construction and repair are often equipped with 18650 batteries combined into a Power Bank. The undoubted advantage of such batteries is the high starting current, which allows the tool to operate with a high power load.

The large capacity of the batteries allows you to continuously use the tool for several hours. If the battery begins to discharge, you can safely charge it without fear of the memory effect inherent in other types of batteries.

Batteries of size 18650 are the most optimal option for a screwdriver due to their small dimensions, high capacity and relative charging speed.

  • 18650 batteries are used in laptop batteries, also combined into Power Banks. They allow these indispensable gadgets to work autonomously for several hours.
  • Given the fairly high electrical energy consumption of a laptop, batteries are used during operation, which together provide a large capacity.
  • Another advantage is that the battery can be recharged when using the laptop from the network; the only thing that needs to be taken into account is that the power supply from the network must be turned off as soon as the charge indicator on the laptop shows that the batteries are charged.
  • Otherwise, the battery life will gradually decrease. The batteries that come with laptops can often be restored, as they are well protected by the laptop case and, as a rule, do not have mechanical damage.

It should be noted that only unprotected batteries are used in laptop batteries and screwdrivers; this must be taken into account when restoring, repairing or replacing them.

So, let's summarize. A large number of modern high-power LED flashlights use 18650 batteries as a power source. Lightweight and compact, these batteries have sufficient capacity to ensure long-term operation of the flashlight and other devices.

Manufacturers are trying to improve the design of batteries as much as possible, and manufacturers of battery-powered devices, in turn, optimize their products for long-term operation with such batteries, both with and without overheating protection.

We hope that this article will help in choosing high-quality and reliable 18650 batteries - necessary for the autonomous operation of various devices both at home and on a camping trip, hunting or fishing.

Advantages and disadvantages

I’ll say right away that Li-ion (lithium-ion, lithium) batteries size 18650 at 3.7v, like many other things, I buy on AliExpress. Links to them are at the bottom of the article.

Why there? Because on AliExpress has a very large selection and you can buy them at a very affordable price..

But precisely because 18650 batteries are very popular, the Chinese are very fond of counterfeiting them, so it’s not worth rushing for beautiful numbers with an unrealistically large capacity or a low price.

I will talk very briefly about the batteries themselves, give some advice - which batteries are better not to buy, how to use them, and give links to really good 18650 batteries, and which ones are better is up to you to decide, because. and their characteristics and purpose differ, although the average operating voltage is the same for all - 3.7v.

Usually, 18650 battery size is: diameter - 18-18.3 mm, height - 65 mm (for batteries without protection). Protected batteries have a diameter of about 18.5 mm and a height of up to 70 mm.

A protected battery, unlike an unprotected one, has a board built into it (charge/discharge controller), and it externally has a positive contact like a small (about 1 mm) protruding pin.

This controller protects the battery from overcharging above 4.2v and from discharging below 2.75-3.0V (different batteries have different lower values, you should look at its description (datasheet), because beyond these values ​​the battery will quickly fail.

Which one is better to use? It depends on what you charge it with and where you use it...

As a rule, normal chargers (designed specifically for charging lithium-ion batteries, for example the 18650 type) have a charge controller and do not overcharge these batteries, so any type can be used in them.

PowerBanks have a full charge and discharge controller, so they use batteries without protection, and in some cases protected batteries will not even fit into the PowerBank due to the protruding contact.

But if you use a battery, for example, in a simple Chinese lantern, a children's car or an electronic cigarette, where there is no built-in discharge controller, then you must use a battery with built-in protection, otherwise it will not last long.

By the way, about electronic cigarettes, mechanical mods and so on. – it’s better to use them high current 18650 lithium batteries, designed to deliver high currents - up to 40-60 A(short term).

  1. Conventional batteries designed for loads of 2-3C (up to 4-5A) will also “die” quickly.
  2. If you use a battery with a step-up voltage converter, then pay attention - at what minimum input voltage does this converter start working?
  3. If it’s from 3 volts, then everything is fine, you can use any type, but if, for example, from 2 volts, then the battery without built-in protection will be “sucked out” completely, which “is not good.”

Regarding the capacity of 18650 batteries: at the time of writing (beginning of 2017), the maximum capacity that I encountered was a maximum of 3400 mAh, and only from well-known manufacturers such as Sanyo, Panasonic, most others, for example LG, Sony, Samsung, etc. - about 3000 mAh, and the price for them is also not the lowest.

Personally, today I prefer already time-tested 2600 mAh batteries from Sanyo and Samsung, which can already be purchased at a very affordable price.

But, On AliExpress you can buy a lot of cheap fakes like Ultrafire, on the cases of which the capacity may be indicated as 3000, 5400, or even 9000 mAh, etc., but the actual capacity of which will be 5 or even 10 times lower!

Also, if you have an 18650 battery and have nothing to check its actual capacity, then just weigh it! Batteries with a capacity of 2000 mAh or more must weigh at least 40 grams! And, as a rule, the higher the actual capacity, the more it will weigh...

Although some “leftist” manufacturers have already learned to “bypass” this point. They just add something inside for weight, like regular sand.

That's why, Don’t chase a low price and big numbers on the case, you shouldn’t save on this!

The most reliable thing is to use trusted links, but always, without fail, carefully read the reviews for a specific battery and then you will not get into trouble.

18650 battery specifications

Most types of small household appliances are powered by rechargeable batteries. The most widely used battery size is 18650. If you need a battery for a flashlight or for an electronic cigarette, most likely you will need the 18650 variety - Sanyo, for example.

General information

The battery size 18650 is the most common in the domestic and foreign markets. They refer to Li-Ion batteries.

There are three classes of lithium-ion batteries:

  • LiCoO2 or lithium cobalt;
  • high-current lithium-manganese LiMnO2, LiMn2O4 and LiNiMnCoO2;
  • LiFePO4 – lithium ferrophosphate.

Each type has its own advantages and disadvantages and is designed to perform specific tasks. LiCoO2 were once the most common and have the highest capacity of any lithium-ion battery.

High-current ones are inferior in capacity to lithium-cobalt ones. LiFePO4 is good in all respects, but is undervalued by the market. All lithium batteries have the ability to hold a charge for a long time.

Let's look at how to decipher the digital designation 18650:

  • first two digits ( 18 ) – diameter;
  • next pair of digits ( 65 ) – length;
  • the last digit () indicates the shape of the battery, in this case – cylinder.

Each battery manufacturer has its own specific markings.

Let's look at our own notation using examples:

  • Panasonic NCR18650B– a type of cobalt chemistry, in simple words – these are class II batteries, but without the use of Mn;
  • Sanyo NCR18650 BF– in this case, the “BF” marking can indicate chemistry, type and capacity.

Where is it used?

This type of battery is widely used in LED flashlights, Power Banks, laptop batteries, screwdrivers, portable handsets for landline phones, electronic cigarettes and even electric bicycles.

How to charge

18650 batteries must be charged regularly, otherwise there is a risk that the battery will fail prematurely. It is also important to follow basic guidelines for charging lithium-ion batteries.

How to charge this box:

  • Charging starts with a voltage of 0.05 V and ends when U rises to 4.2 V. These are acceptable parameters that are the safest for batteries.
  • You can charge the battery at charging currents of 0.5 A and 1 A. 0.5 A is the optimal indicator, and at 1 A the charging process will proceed faster. It is not recommended to speed up the process unless absolutely necessary.
  • Charging time should not exceed three hours, otherwise there is a high risk of damage to the chemical structure of the battery. An exception may be situations where the device has a control system. In this case, it determines the charging time itself.
  • It is highly undesirable to allow 18650 to deep discharge. In this case, it is very difficult to restore the previous parameters of the product. It is much easier for the owner to periodically recharge the device for a short period of time.

The sales consultant will tell you approximately how long it takes to charge the device. This depends on the battery capacity and its original condition.

Charging devices

Today, buying a charger is not a problem. There are many devices on sale of different prices, but choosing a charger is not only based on budget. You should also pay attention to the types of devices.

  • The single-socket charger has a current level of 1 amp. This is often the most budget-friendly option. It is suitable for those who do not have to charge batteries more than several times a year.
  • A charger with two sockets is used for elements with voltage levels up to 4.2 V. At higher voltage levels, the battery will fail. Typically, such devices are equipped with an indicator that monitors charging time.
  • There are also universal devices, with which you can charge not only lithium batteries, but also nickel-cadmium batteries, as well as boxes from several devices.

The quality of the charger depends on its cost. More expensive devices have indicators and relays.

Those who have the desire and skill can make charging for lithium-ion batteries with their own hands. To do this, you need to know the battery charging parameters, as well as the operating principle of the electrical circuit.

Let's consider the simplest method, which even a schoolchild can cope with. We will replace the professional charger with an old charger from Nokia or Samsung.

The wires are freed from the sheath, separated into plus and minus (the positive wire is usually red, and the negative wire is black). A battery is attached to the exposed wires. You can do this using plasticine. The element is connected to a computer or network, observing polarity.

It is advisable to monitor the process. It will take about an hour to charge the battery this way.

Knowing the basic properties and indicators of current and voltage, it is easy to carry out the charging process without harm to the battery. A careful attitude will allow the product to last as long and efficiently as possible.

Types and markings of lithium-ion batteries 18650

We received quite a lot of questions from readers about 18650 lithium-ion batteries. Therefore, we decided to write a small FAQ on this type of lithium battery. 18650 battery cells are in demand in the modern market.

They are used in laptop batteries, various flashlights, power banks, and some types of power tools. In this note, we will consider the main issues that interest people most.

Namely, types of 18650 elements, issues related to their labeling, protection, pros, cons and price.

Types of 18650 batteries

To begin with, it is worth mentioning the main types of 18650 batteries, which differ in cathode material. The properties of batteries such as capacity and maximum permissible discharge current largely depend on this.

  • LiCoO2 (lithium─cobalt). These batteries are the most common and have the largest capacity values ​​among models made using Li─Ion technology;
  • LiMnO2 or LiMn2O4 or LiNiMnCoO2 (lithium-manganese group). In terms of their capacity, they are inferior to the first group, but they have a high discharge current (5─7*C);
  • LiFePO4 (lithium ferrophosphate). These battery cells are superior to the previous ones in most respects, but inferior in capacity and voltage. They have a service life of up to 1 thousand charge-discharge cycles and charge in less than 1 hour.

Now about 18650 batteries in general. These are cylindrical elements in shape reminiscent of AA (“finger”) and AAA (“pinky”) form factor batteries. But 18650 exceeds them in size. The length is 66.5, diameter ─ 18 millimeters. For comparison, for fingerlings these values ​​are 50 and 14 mm.

The output voltage of the 18650 battery is 3.78 volts. The capacity of the most common batteries is in the range of 2000-3200 mAh. Less common are banks with a capacity of 1000, 1100, 1500 mAh.

How to decipher the markings of 18650 batteries?

Let's look at the marking of 18650 lithium-ion cells using the following example: ICR18650-26F M.

The first letter I indicates that the battery is made using lithium-ion technology. The second letter indicates the cathode material. In our case, cobalt. The following options are available:

  • C ─ cobalt;
  • M ─ manganese;
  • F ─ iron phosphate.

Form factor Explanation

And at the end of the marking there is a designation of the capacity. In this example, the capacity is 2600 mAh. But usually the ending of the marking differs greatly depending on the manufacturer. Here, almost everyone can have their own version.

18650 battery protection

According to safety requirements, the voltage of 18650 lithium-ion batteries must be in the range of 2.5-4.2 volts during operation. To meet this requirement, some 18650 batteries are equipped with protection. It is a small printed circuit board.

This board is soldered to the terminals of the element using steel or aluminum tape. As a rule, large manufacturers do not produce such protected elements in mass production. They produce unprotected elements that are used in devices with charge-discharge controllers.

  • An example would be a laptop battery or a screwdriver.
  • As a rule, protected 18650 lithium-ion cells are made in small batches in China.
  • A protection board is soldered to the unprotected battery, and the entire structure is wrapped in thermal protective film. When purchasing such an element, you need to take into account that its length will be slightly longer (1.5─2 mm).
  • It is worth considering that installing protection on lithium-ion 18650 increases the length of the element. And when there are several of them, this increase is summed up.

As a result, a set of such elements may simply not fit into the flashlight body or interfere with the closing of the lid, which is usually made with a negative contact.

It must be remembered that protecting the 18650 element will not protect the device and batteries from overheating. Its role is to control tension. Many people use 18650 batteries in flashlights without protection. This can be done relatively safely if you have 1 element in the lantern. When several elements are installed, they must be protected.

Pros, cons, price

The advantages of 18650 cells include all the same things that are inherent in other lithium-ion batteries:

  • High energy intensity;
  • Slight self-discharge;
  • There is no “memory effect”;
  • Small dimensions and weight.

The disadvantages include:

  • 18650 sensitivity to overcharge and overheating. The problem is partially solved by installing a protection circuit;
  • These battery cells require more care than other types of batteries. This particularly applies to storage. They must be stored at 40-50% charge at a temperature of 5-15 degrees Celsius;
  • Aging (degradation) of lithium-ion batteries occurs from the moment of their release. Even if they are not used.

The spread of 18650 on the market is quite large. We can say the following with confidence. On Aliexpress, the average price of 4 18650 elements with a capacity of 2600 mAh (without protection) is around 600-700 rubles.

  1. In Russian online stores, one battery cell (with protection) can cost 600 rubles.
  2. Therefore, even taking into account the risk of low-quality goods from Uncle Liao, it is more profitable to order from China.
  3. In addition, recently they have been making lithium batteries of normal quality.
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  5. Vote in the poll below and rate the material! You can leave corrections and additions to the article in the comments.

18650 Li-ion batteries (lithium)

18650 batteries(sometimes designated as 168A) is one of the most common sizes used in professional LED flashlights.

U lithium-ion batteries form factor 18650 is the highest in terms of capacity/dimensions ratio. They are cylindrical in shape, 18 mm in diameter and 65 mm in length. Capacity Li-ion batteries 18650 3.

7V from different manufacturers is 2200 - 3400 mAh. Currently, the largest capacity of existing batteries is Panasonic 18650B 3400 mAh

Brief description of Li-ion batteries.

Lithium-ion battery (Li-ion)- This is the most widely used type of battery. They are used in devices such as laptops (by the way, laptop batteries most often use 18650 batteries connected in series.

Replacing the original batteries in a laptop with Panasonic NCR18650B 3400mAh batteries will help restore the “dead” original laptop battery, and will also more than double the battery life), phones, electric cars, video cameras, radio stations and digital cameras.

And of course, Li-ion batteries are actively used in LED flashlights for various purposes. The first Li-ion battery was released by Sony in 1991.

Currently, the best Li-ion batteries in terms of key characteristics (real capacity and level of voltage drop under load) are Panasonic.

In our online store you can buy Li-ion batteries for both LED flashlights and other equipment.

Characteristics of Li-ion batteries.

Depending on the electrochemical circuit Li-ion batteries 18650 show the following characteristics:

  • In the charged state the voltage is 4.2 V, in the discharged state 2.5 V
  • Energy density: 110 - 250 W*h/kg.
  • Internal resistance: 5 - 15 mOhm/1Ah.
  • Number of charge/discharge cycles until 20% capacity is lost: 1000 - 5000.
  • The maximum permissible current in the charger is calculated on average as follows: the battery capacity must be divided by 3. For example, take a Panasonic 3100 mAh battery.
  • You need 3100/3=1033 mAh (this will be the maximum charging current, which will not damage the battery). With a higher charging current, the battery will charge faster, but will withstand fewer charge/discharge cycles.

Self-discharge at room temperature: 3% per month. Operating temperature range: -10 +60 °C (at sub-zero temperatures, battery charging is not possible). 18650 stands for: 18 mm diameter and 65 mm length.

  • High capacity.
  • Low self-discharge.
  • No memory effect. Memory effect is an irreversible loss of battery capacity when recharging a battery that is not completely discharged.
  • In other words, Li-ion batteries do not need to be completely discharged before charging, unlike some other types of batteries.
  • No maintenance required.

Modern professional LED flashlights use an electronic circuit (driver) to control the LED.

If you want to buy batteries (lithium-ion or nickel metal hydride) for use in LED flashlights, you need to take into account the flashlight manufacturer's recommendations on which batteries are best suited for it.

When choosing batteries In addition to capacity, it is necessary to take into account security and some other parameters. Carefully read the documentation for the flashlight and, if necessary, contact us for advice.

TO batteries Of course you need a charger. In our store you can buy chargers for Li-ion batteries, Ni-MH batteries and batteries other types that are used in LED flashlights.

Even a good thing can be ruined. This fully applies to batteries (in this case, a bad “protection board”).

As written earlier, the protection board saves the battery from overcharging, overdischarge, and short circuit. It is worth paying special attention to its quality. Because

being a link between the consumption source and the battery, it can become a bottleneck and not reveal the full potential of the battery (the characteristics of the battery will be limited by it).

In addition, the protection board itself consumes electricity to a greater or lesser extent depending on the quality.

It will be most clear if I start with an example.

Panasonic 3400 mah batteries are the most common batteries at the moment. Their cost can be 800 rubles or 500 rubles.

What's the catch? That's right, in defense (for most cases this statement is true.

But there may be other nuances regarding batteries rejected due to discrepancies in capacity, used/used, expired and even counterfeit batteries. We will not consider all this here). There are several types of protection boards.

From left to right: very bad, good, very good :)

  1. In the first option, only 1 mosfet is installed, a simple voltage controller. In general, in addition to the terrible quality of workmanship, such protection is not safe for the flashlight itself (it can burn out from the load and short-circuit the battery, causing it to explode. By the way, the flashlight battery breaks into fragments). And one more thing - this protection does not hold high currents; it will trip early when the battery is only half discharged. Thus, the operating time of the flashlight will be 2 times less. This applies only to the MAXIMUM flashlight mode. In low modes the battery will work as expected.
  2. The second protection is normal, it holds current up to 4-5 Amps, which is quite enough for most flashlights. It doesn't get too hot and is quite reliable.
  3. The third option uses as many as three mosfets. This gives: operating current up to 7.5A (the full potential of the battery in terms of current output is revealed), low consumption (more capacity can be squeezed out of the battery), precise operation at critical currents/voltages. These are the protection boards installed on our batteries!

Construction and alteration

Lithium-ion batteries entered our lives along 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.
  • Higher output voltage. 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 off-grid devices to cylindrical lithium-ion batteries and assemblies made from 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 ones - it is digital, for example, 14500 or 18650.

This coding is unusual, but it is convenient for selecting the required battery according to the size of the electronic device slot.

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 are used.

For safe battery operation, a charge-discharge controller is required.

When assembling batteries, only unprotected lithium-ion batteries are used! 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 - you need to buy a 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 point to consider. 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.

18650

Lithium-ion batteries Li-ion Olight, Xtar, Panasonic, LG, Samsung, Sanyo, Soshine, standard size 18650 with a voltage of 3.7 V.

A lithium-ion battery consists of electrodes (cathode material on aluminum foil and anode material on copper foil) separated by porous separators impregnated with electrolyte.

The package of electrodes is placed in a sealed case, the so-called jar, the cathodes and anodes are connected to the current collector terminals - plus and minus of the battery.

The housing has a safety valve that relieves internal pressure in emergency situations and violation of operating conditions.

Lithium-ion batteries vary in the type of cathode material used. The charge carrier in a lithium-ion battery is a positively charged lithium ion, which has the ability to integrate into the crystal lattice of other materials, such as graphite, to form a chemical bond.

Batteries are extremely sensitive to excess voltage during charging, at which point the battery can catch fire.

Therefore, in our online store we sell only protected batteries, in the case of which a special electronic board for monitoring external/internal voltage is built in - a protection chip that protects the battery from exceeding the charge voltage - overcharging and from deep discharge, in which the voltage on the battery bank drops below threshold of 2.75 Volts and the battery will fail.

The peculiarity of Li-ion is that it is almost impossible to charge a battery with a voltage close to zero. This board can also optionally control the temperature of the battery, turning it off when overheated, and limit the depth of discharge and current consumption.

But do not be afraid that the working volume of stored energy remains unused, since the discharge area from the upper limit of 4.2 V to 2.75 V is 90-95% of the entire battery capacity.

The operating time and number of life cycles of Li-ion batteries depend primarily on the charger used.

High smart chargers will not allow overcharging or undercharging of your Li-ion batteries; it will automatically turn off when the charging cycle is completed or the permissible temperature is exceeded, which may be unsafe.

The smart charger uses a constant current charging profile ( CC) and charge with constant voltage ( CV), this charging method is recommended and the fastest, preserves their resource and does not reduce their capacity of your Li-ion batteries over time, at which they serve their full service life.

Smooth start of charge ( TC) to prevent damage to the battery when charging with high current. Wide range of charging currents from 0.25 to 2 Amps for charging li-ion batteries with a wide range of capacities.

Are you wondering: “Where can I buy 18650 batteries inexpensively in Moscow?” Available in the Fonarik4you online store.

ru You can always find and buy almost any type of batteries and smart chargers for them, as well as order a charger by cash on delivery by Russian Post to any region of Russia.

Batteries are used in the automotive industry and in the repair of air conditioning chillers.

AAA AA/14500CR123A/16340 18650 26650/32650 Olight/Fenix/MagicShine

How to choose a battery

18650 batteries belong to a large range of lithium-ion (Li-ion), which are widely used as power sources in many modern electronic devices: mobile phones, mp3 players, flashlights, laptops, etc.

The big advantage of lithium-ion batteries over conventional batteries, which are often called “dry” batteries, is that batteries, unlike batteries, are rechargeable elements, which means they will last much longer.

In general, today lithium-ion batteries have the best characteristics among all power sources; the only disadvantage we can note is the relatively high cost.

To ensure that the cost of batteries does not hit the buyer’s wallet, you can buy inexpensive 18650 batteries from us.

  1. The operating voltage of the lithium-ion battery is from 2.75 to 4.2V. It should be noted that “lithium-ion” really does not like deep discharge; if the cell voltage drops below 2.5V, this negatively affects the battery capacity, to the point that it may fail.
  2. The upper voltage level of 4.2V should also not be exceeded; ignoring this rule can have even more serious consequences, in addition to destroying the battery; exceeding the voltage can lead to an explosion of the battery.
  3. Therefore, it is very important to use so-called “smart chargers” designed for charging Li-ion. Such charging will not supply a voltage higher than 4.2V, and will also reduce the current as the battery voltage increases.
  4. The capacity of lithium-ion batteries per unit mass sets an absolute record; no other batteries are capable of holding such a charge at a predetermined mass.

Recently, lithium-ion batteries of the 18650 size have become very popular. These batteries are similar to regular AA batteries, but slightly larger.

Almost all powerful flashlights and power banks use 18650 batteries. Another 18650 are used in power tools independent of the mains: screwdrivers, soldering irons, drills.

Many children's toys (remote control cars, toy aircraft, etc.) also use batteries of this size.

You should beware of fakes at the moment, 18650 batteries have the largest capacity of 3400 mAh. If a manufacturer claims a 18650 battery capacity higher than 4000 mAh, you can be sure that this is a hoax.

Many Chinese batteries are famous for this trick; their stickers say 4200, 4400, 4800 and even more than 5000 mAh. It’s worth knowing many of the heroes by sight so that you don’t accidentally purchase such a battery.

For example, the Bailong company reports 4200 mAh, while the real test shows from 600 to 800 mAh. UltraFire, TrustFire are approximately the same type of batteries.

Good batteries are made by such manufacturers as: Sanyo, Samsung, LG, Panasonic, CJ. Their capacity is usually from 2200 to 2600 mAh, but the main thing is that the capacity is honest.

If you don’t take my word for it, I suggest you conduct an experiment yourself. Check how long the flashlight will work, say, with an industrial LG and Bailong.

However, there is a more visual test: take a high-quality 18650 battery in one hand and a Chinese counterfeit in the other, you will be surprised at the difference in their weight.

18650 battery is quickly becoming popular in our society. Its main advantage is multiple charging up to 500 times. Its shape is similar to . Dimensions vary depending on the degree of protection.

18650 battery

Many users sometimes confuse this battery with a regular 1.5 volt battery. But this is wrong, his tension is much greater. Yes, and the dimensions are different.

18650 battery what is it?

This is a rechargeable battery with the ability to recharge. Some types have a built-in port and the ability to receive charge from a USB connector. This solution is very convenient.

Thus, from the above definition it becomes clear what kind of tr18650 batteries are.

18650 battery specifications

Below we present to your attention the main parameters of this battery.

Voltage

After analyzing a number of online stores, a conclusion was made. Most 18650 batteries are 3.6 volts. But there are options with 3.7 V. At the moment of full charging, the voltage increases to 4.2-4.3 V.

How many amps are in a 18650 battery?

The current strength depends on the specific battery model. The number of amperes in a 18650 battery, according to some sources, is from 0.5 A and above.

Battery capacity 18650

Color

The markets can have both the most common colors and exclusive ones. For example, you can find brown 18650 chocolate batteries.

Main advantages

  1. Easy to maintain.
  2. Low specific gravity.
  3. Low self-discharge level.
  4. High energy density.
  5. The 18650 battery has no memory effect.
  6. Service life is from 7-10 years.

Battery type 18650

There are three main options:

  • Lithium iron phosphate, also called ferrophosphate, also LFP, LiFePO4, IFR. (Lithium Iron Phosphate).
  • Lithium Manganese Oxide. They are also IMR, LiMn2O4, NMC, LiNiMnCoO2, LiMnO2, INR. High current.
  • Lithium Cobalt Oxide. These include LiCoO2, NCR, ICR. They have a high .

First

Considered the safest. Their operation is quite stable and with high efficiency. They have an iron phosphate cathode. This means that it has zero toxicity. The battery is tolerant of high temperatures.

The 18650 battery does not have a charge controller. If the case is severely deformed, these batteries may explode or ignite. This happens in very rare cases. 18650 is weakly sensitive to incorrect operation. For example, reducing resistance.

Second

Quite in demand by consumers. They manifest themselves as stably operating batteries. Many manufacturers write that option No. 2 18650 is safe. But in reality this is not entirely true. They don't have a charge controller.

The main advantage of such batteries is that they work with low resistance for a long time. Compared to the cobalt type, manganese ones last longer. Their capacity and current are balanced. The maximum charging current is 4.2 volts. Do not neglect the current strength, this may deteriorate the battery and cause an explosion. The current level affects the charging time.

Can withstand a discharge of 2.5 volts. The anode is made of graphite. With low resistance and high current, gas may escape. These batteries are of sufficient quality and are recommended for widespread use.

Third

Where is the plus of the 18650 battery?

It is not so easy to determine where the negative terminal is located. Very often it is almost impossible to determine by appearance.

Those chargers that have 2 slots for batteries with 4.2 V. If you increase the voltage the battery will die. Fortunately, there is an indicator that monitors the process.

In retail trade you may find mixed types of chargers. They are designed for both 18650 battery and regular .

Devices that have a high cost are more richly equipped. They have relays and all possible control indicators. Therefore, charging for 18650 lithium-ion batteries will be more reliable.

What to do if 18650 does not charge?

  1. Check the manufacturing date, it may have already expired.
  2. Think about how many charge and discharge cycles you have already done. If it is more than indicated in the battery characteristics, then it has already served.
  3. Check if it is working properly. The wire may have been crushed.
  4. Pay attention to the contacts. There is a possibility that the contact between the battery and the tin plate may be damaged. The cause may be plaque, rust or oxidation.
  5. Check if there is electricity in the house.

These five points will help you understand why the 18650 battery does not charge.

How to charge a 18650 battery using a phone charger?

The video below provides instructions on how to do this correctly. Here's what you'll need:

  1. Mobile charger TR 4056.
  2. Soldering iron.
  3. Wires.
  4. USB cable with suitable connector.
  5. Phone charger.

After assembly, all that remains is to connect it to the phone's charger using a USB cable.

But charging 18650 from a solar battery is possible if you create a special device that delivers the required current. But in reality, you will have to try to bring the design to life. There is no finished development yet.

Watch the video on how to build a cool battery with solar panels.

Advice! It is best to buy for 18650 li ion batteries CV or CC.

How to make a charger for 18650 batteries?

Charging for li ion batteries can be done on the LM 317 chip. Below is a diagram and what it looks like assembled.

The video provides an example of creating a charger for this battery.

How to drain a 18650 battery?

Let's carry out a safe discharge. To do this you will need:

  • 12 volt incandescent lamp.
  • 2 wires.
  • Battery to discharge.

Now all that remains is to solder the wires to the lamp and connect to the 18650 battery. A smooth discharge will occur.

You can also perform discharge using a special unit shown in the video below.

The maximum discharge current can reach up to 35 A. But it is better that this is more a myth than a reality. It is best to use the gentle mode and discharge with a current of 1 ampere.

The discharge current should not be more than 2 times the capacitance value (2C). For example, a battery with a capacity of 2000 mAh will be equal to 4000 mAh. The voltage should not be less than 2.5 volts.

How to check if a 18650 battery is working properly?

To check, use a regular multimeter. With this device we measure the voltage and determine the voltage of the battery. A normal 18650 battery contains 3.6-3.7 volts.

If the battery starts to get very hot during charging and its temperature reaches more than 40 degrees, it is better to get rid of it.

It is believed that when the voltage is less than 1 volt, these batteries should be thrown away. But if it accepts a charge, you can still use the battery.

How to replace a 18650 rechargeable battery?

In reality, this battery is not replaceable. You can try using 3-4 AA batteries. But they won't last long. In addition, the voltage will vary greatly. Therefore, be careful! Yes, and 3 pieces will not fit into the case; you will have to solder the wires and hook them to the contacts.

There is a second name for this 168 A battery. But in fact, there are almost no analogues to this battery. You can also try the 18700 option.

How to make a battery from 18650 batteries?

To do this, you should prepare the following:

  1. The required number of 18650 batteries.
  2. Wires or thin tin plates.
  3. Connector for power output. Or just two wires, preferably black and red.
  4. Electrical tape or container in which the batteries will be securely fixed.

The battery assembly from 18650 batteries is carried out according to the following principle. The negative end must be connected to the positive end. It is worth deciding what kind of connection is needed, parallel or sequential. The first one saves space in length, but second in width. The figure below shows what the second connection looks like. This is a laptop battery.

Scheme of sequential battery connection.

Parallel connection:

See the video for assembly details.

Application of 18650 batteries

So where are 18650 batteries used? This battery is used in various technical gadgets. Below is a list of them:

  1. An 18650 battery is inserted into the flashlight.
  2. It is needed for vaping or electronic cigarettes.
  3. It can be used as an external battery with replaceable 18650 batteries. Essentially, it is a power bank with 18650 batteries.
  4. Quadcopters.
  5. Radio controlled toys.
  6. Airsoft drives.
  7. For powering electric motors.
  8. Laptops.
  9. Screwdrivers.
  10. Drills.
  11. Players.
  12. Electric bicycles.
  13. Portable telephone handsets.

Braid for 18650 batteries

When purchasing this battery, do not neglect the packaging. The case for 18650 batteries performs a protective function. Prevents accidental ingress of moisture and contact with metal. In addition, the 18650 battery is quite easy to carry in the box.

The braid looks like this:


How much do 18650 batteries cost?

Prices for this device are different everywhere. It all depends on the specific company, the characteristics of the battery and the store itself.

At the moment, the price tag for batteries with a capacity of 3500 mAh fluctuates around 1800 rubles. On Aliexpress it is 1000 - 2000 rubles. But you understand that you will have to wait a long time.

A battery with a capacity of 2500 mAh costs 200 – 1400 rubles.

The difference between 18650 and AA batteries

The main difference is this:

  1. Size. It may be a couple of millimeters larger. It all depends on the specific model.
  2. Charge. The voltage level is 3.7 volts. At the moment of energy accumulation it reaches 4.2-4.3 V.
  3. Battery type. That is, it is recharged many times. Usually 500 – 1000 times.

If you want to replace the AA with an 18650 battery, be sure to check the voltage. By connecting two AA batteries we get 3 volts. And this device produces about 3.7 V. Therefore, it is better to use it in flashlights and equipment that can withstand excess voltage.

They can replace three AA or batteries, but again there will not be enough energy. Again, you need to think about which products will operate at reduced voltage. The radio receiver and player may work well, but the engine or heating element will work rather poorly.

Li-ion 18650 battery is susceptible to aging

The wear process occurs regardless of whether a li ion 18650 battery is used or not. There is an opinion that after a few years from the moment of manufacture they should be thrown away. Once a year the battery loses charge by as much as 10%. Before you buy it, look at what year it was made.

Another disadvantage is the inability to store discharged for a long time. This leads to damage. Aging also depends on the temperature that surrounds them. They can work perfectly from -20 to + 20 degrees. Some species are able to function at +50.

What does protected battery mean?

As a rule, lithium-ion batteries should have a voltage of 2.5-4.2 volts. There is a special defense that it was not rejected. It is made in the form of a small board with radio elements. This device is attached to the negative pole of the battery.

The board protects against overload and lock. It is soldered to the negative using a special metal tape. Such items are marketed under various brands. This microcircuit slightly extends this type of power supply. If there are two words Short-circuit and Protection, then the battery is protected.

There is also mechanical protection. It is triggered when a large amount of gas accumulates.

18650 specifications table

18650 battery repair

The protective board fails periodically. This electronic filling can be removed and the battery can be used again.

Step-by-step action plan:

  1. Remove the cellophane wrapper.
  2. After this, you will see a conductor running from the positive pole to the microcircuit. This whole thing is hidden under the minus. In the event of an emergency, the board breaks this contact.
  3. Remove the board and remove the conductor. If necessary, spot welding can be cleaned with sandpaper.
  4. It is worth removing the shell enough so that the contact of the device touches the contact of the battery.
  5. Now wrap it with tape or a special adhesive film and you can use it.

After doing these steps, the 18650 battery will lose 1 millimeter.

  • Lithium batteries better than nickel ones in many respects: higher current output and lower voltage drop under load - the screwdriver turns equally well both when fully charged and when already discharged. Lithium batteries do not have a memory effect - they can be recharged without compromising their capacity (unlike nickel batteries). The self-discharge of lithium batteries is several times less than that of nickel ones; the screwdriver will last quietly for six months and lose only a couple of tens of percent of its charge, while the nickel one will be completely discharged.
  • Voltage assembly depends on the number of lithium “cans”. In a fully charged state, one bank has a voltage of 4.2 Volts, while the operating voltage is around 3.7 Volts (in this section the discharge graph is almost horizontal)
  • Number of cans for the battery is selected as follows: look at your old nickel battery. What voltage is indicated on it? Select the number of lithium cans so that their total voltage is close to the nickel assembly, or slightly higher than this value. The voltage of a lithium can in the calculation is taken to be 3.7 Volts: 2 cans - 7.4 V, 3 cans - 11.1 V, 4 cans - 14.8 V, 5 cans - 18.5 V. You can also count at the maximum - look at the output voltage of the charger for a nickel battery, this will be voltage of a fully charged screwdriver. We count lithium cans as 4.2 Volts per can: 2 cans – 8.4 V, 3 cans – 12.6 V, 4 cans – 16.8 V, 5 cans – 21 V. Don’t be afraid to assemble a battery that is a volt or two more than the old one: it will turn the motor a little faster This WILL NOT BURN. Unless, of course, you clamp it in a vice and give it full throttle.
  • Protection board (BMS) performs several functions at once: protects the battery from overdischarge (lithium does not like this) and protects against short circuits, saving you from exploding cans. In both cases, the BMS simply disconnects the assembly from the load until the causes of the trip are eliminated. Some BMS models do not leave protection until you apply charging voltage to the board. BMS models with cell balancing additionally perform the very important task of balancing the voltage of the cells in the battery during charging, charging them to the same voltage, which ensures the most efficient and safe use of the battery.
  • Charge the battery lithium batteries require a special charger that produces the required voltage and limits the current; such chargers are called “CC CV”, which means constant current constant voltage - the law of charging lithium batteries. ATTENTION! BMS board is not charger! The lithium assembly must be charged with a separate special charger, the voltage of which is equal to the maximum voltage of the assembly: 2 cans – 8.4 V, 3 cans – 12.6 V, 4 cans – 16.8 V, 5 cans – 21 V. I will leave links to Chinese charging power supplies below. These chargers automatically turn off the battery when charging is complete. It is very convenient to put a standard 5.5x2.1 mm socket on the battery, because such a plug is on all charging power supplies.
  • Indicator The battery charge is a little bit, but it drains the battery (LEDs are lit), so you can’t just connect it to the assembly; you need to do this through a button or switch. You can also connect it directly to the screwdriver motor, but preferably through a diode. Thus, by pressing “full forward” you will see the battery charge on the indicator!
  • What to buy for assembling a lithium battery for a screwdriver?
    High-current batteries, I wrote above how to count the number of cans. You will find links to different batteries below; here I recommend powerful and capacious SONY VTC6 batteries. With welded strips for easy assembly. And ordinary cans for independent welding/soldering. Slightly cheaper and not as powerful HG2, link one, link two. You can buy such batteries in vape shops.
    Protection board (BMS) according to the number of selected cans. There are links to powerful BMS with balancing with connection diagrams. I’ll duplicate it here: 3 cans, 3 cans, 4 cans, 4 cans, 5 cans, 5 cans. For particularly powerful screwdrivers, use powerful BMS. The seller has them for different numbers of cans
    Charger for the appropriate number of cans, links are below, I will duplicate them here: 3 cans 1 ampere, 3 cans 2 ampere, 4 cans, 5 cans
    5.5x2.1mm socket for convenient charging, link 1, link 2
    Charge indicator for the corresponding number of cans: link 1, link 2.
  • Safety precautions plays an extremely important role when working with lithium batteries! Lithium batteries are a powerful and very dangerous thing; if used incorrectly, a lithium battery can burst or catch fire. This can happen for three main reasons: too much load, overheating and voltage exceeding limits. Special cases:
    • Overheat– do not leave batteries in the sun!
    • Short circuit– if you solder cans, do it as carefully as possible!
    • Reload– use only lithium chargers!
    • Overdischarge– do not force the battery!
    • Operating a hot battery
    • Mechanical damage to the can
  • What to do what if the battery still fails? Tips from firefighter Andrei Delon:
    • You can’t extinguish lithium “with just improvised means”; until it burns out, it will create inconvenience and scream loudly about itself.
    • If it catches fire, the most ideal thing is to throw it into a pan, etc. To prevent it from smoking too much, cover it with whatever you need (salt, sand, earth, soda).
      NEVER extinguish fires with water or foam fire extinguishers.
    • To extinguish lithium, there are special means, powder mixtures PS-11, PS-12 and PS-13 (ordinary fire extinguishers do not work!)
    • Some powder fire extinguishers can even have the opposite effect, for example with a mixture of PS-2.

Power supplies for various devices have long been part of our lives. They help keep communication lines running when the usual conveniences are too far away. An LED flashlight will not work without a battery. Therefore, today there is a rapid increase in the production of new batteries. The 18650 battery was developed to power laptops, hand-held power tools and other machinery.

The cathode for such elements is made of various materials. Lithium 18650 batteries are divided into several types, which are directly dependent on the material from which the cathode is made:

  • LiCoO2. This battery is most widely used due to its large capacity. Manufacturing is carried out in accordance with the Li-ion technological process.
  • LiMnO2. High current 18650 lithium manganese batteries. The discharge current, with a small capacity, reaches 5–7 A.
  • LiFePO4. These lithium ferrophosphate batteries are far superior to other models. But they differ in minimum voltage and low capacitance.

Lithium-cobalt elements are widely used. They differ from similar elements in their large capacity. The service life of such a battery is much longer.

Description and characteristics of the 18650 battery

They are distinguished by their cylindrical shape and are available in several types:

  • finger - AA;
  • pinky - AAA.

The dimensions of the 18650 battery are slightly larger than conventional batteries:

  • length – 66.5 mm;
  • diameter – 18 mm.

Technical specifications:

  • output voltage is 3.78 volts.
  • Capacity - 2000–3200 mAh.

The 18650 lithium ion battery has found constant use in devices that require maximum capacity:

  • Laptop batteries.
  • All kinds of modifications of LED lights.
  • power bank.
  • Chargers for mobile gadgets.

What is the meaning of the designation printed on the surface of 18650 batteries?

To figure it out, let's take a lithium-ion battery, brand ICR18650-26F M.

  • “I” - this symbol marks all elements of this type, the production of which is carried out according to the same technological process.
  • "C" - indicates the material from which the cathode is made. For example, M stands for manganese, F for iron phosphate, C for cobalt.
  • "R" stands for battery.
  • 18650 - divided into two sections - 18, 65. Indicate the diameter and length.
  • 0 – designation of shape, meaning cylinder.

Important! Battery labeling does not have the same meaning. Each manufacturer has it individually, so it can have big differences.

To extend the life of a good battery, professionals advise adhering to several important rules.

Never allow the battery to become completely discharged. 18650 does not have a "memory effect". Therefore, there is no need to wait until it is completely discharged. If the charge level drops to zero, the battery life will be greatly reduced. For example, a zero capacity charge can be performed 400–600 times. If the residual capacity reaches 15%, the number of charge cycles will greatly increase to 1000–1200.

The battery must be completely discharged once every three months. Testing has shown that it is pointless to fully charge a lithium-ion battery. Its capacity decreases and its service life decreases. Professionals recommend completely discharging the battery at least once within three months, and then charging it again.

Interesting video about testing 18650 batteries

A full charge level must be maintained for 10 hours. As a result, the container will “swing” perfectly and its original performance will return. In any case, regardless of whether the “memory effect” exists or not, the charge threshold remains unchanged.

It is very important to store the 18650 battery properly. It is best to store the cells when the charge level does not exceed 35-50%. The room temperature must be maintained at 15 degrees. The battery should not be exposed to direct sunlight. The battery is afraid of ultraviolet radiation.

It is unacceptable to store the battery in a discharged state for several months. It will simply stop working. We'll have to get rid of him. A charged battery can be stored much longer, but within certain limits. Otherwise, history will repeat itself, it will simply fail.

The 18650 battery should not get very hot. High temperatures cause enormous damage to the condition of the battery. Overheating is associated with several reasons:

  • Direct exposure to sunlight.
  • Long-term operation;
  • Heat sources, such as a radiator, are located near the elements.

Always remember! The 18650 battery cannot be used at temperatures of 40 - +50 degrees.


The battery should be charged regularly. Otherwise, even a very good battery will become unusable much sooner. Therefore, it is very important to follow the basic rules for charging lithium batteries.

The initial charge voltage should not exceed 0.05 V. At the end of charging, it rises to 4.2 V. The specified parameters are considered the safest for such batteries.

Charging can also be carried out if the charging current is in the range of 0.5 - 1 A. The best indicator is 0.5 A, if the current increases to 1A, charging will proceed a little faster.

Experts do not advise specifically speeding up the process unless it is particularly necessary. It takes no more than three hours to charge the battery. Exceeding this period may cause a change in the chemical structure of the battery.

Only if the system is equipped with a control mechanism can the charging time be violated. The controller itself will determine when it is necessary to turn off the charge.

The 18650 battery should not drain to zero. After this, no charge will be able to return the battery to its previous technical characteristics. Therefore, you need to constantly recharge the product and monitor its condition.

How to correctly determine the polarity on a 18650 battery

If you compare ordinary batteries with lithium ones, you will notice that the latter’s positive and negative terminals do not have much difference. However, it is quite easy to see where the plus and where the minus are. The positive contact has several small holes (3-4 pieces); it protrudes slightly forward. The negative contact has a completely flat surface.

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 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.