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 high-capacity cells. 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.

All of these types are classified as lithium-ion batteries. Therefore, we can say with certainty that their production technology is the same.

Lithium-cobalt types

Lithium-cobalt batteries

This type of battery has the highest capacity. But despite this, you need to be quite careful with such batteries, because the lithium-cobalt system is quite dangerous and unpredictable. Such batteries must not be charged by fast charging. For other types, it is quite safe to use the accelerated method.

Lithium-cobalt batteries cannot be used in devices that place a large load on the battery. If you know that the equipment can drain the battery in half an hour, refuse to use lithium-cobalt products in it. Otherwise, you will need to quickly eliminate the electrolyte fire.

This type is now widely used for electronic cigarettes. At the same time, approach the issue of choice with special responsibility, because fakes are very common. The upper limit voltage that can be used to charge a 18650 battery is considered to be 4.2 V. At a higher voltage, the battery may overcharge, which is best avoided. It is forbidden to use too powerful charges, because their operation negatively affects the chemical aspect of the battery. The device not only deteriorates, it can explode or burn, so it is better to avoid violations.

Therefore, before charging the battery, it is better to purchase a “smart” charger. It has various parameters, as well as current adjustment.

Lithium manganese types

Lithium manganese batteries

These are the best 18650 batteries, which are quite in demand among users. They are distinguished by stable operation compared to the previous type we described. Most lithium-manganese batteries are not equipped with a charge controller, and manufacturers write on the products that they are safe.

The advantage of this type of battery is its ability to work quietly and for a long time with low resistance. In fact, this is also not very good, however, comparing them with cobalt batteries, we can say that manganese batteries have a longer service life. Lithium manganese batteries are designed with an excellent capacity to power ratio. But despite this, their volume is less than that of similar cobalt ones. Charging restrictions. The maximum voltage will be 4.2 volts. The current strength should also be regulated: high supply significantly worsens the condition of the battery and can also lead to an explosion of the battery. The current strength directly affects the charging speed.

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

As for manganese batteries, they are considered reliable compared to cobalt batteries, since they can withstand a high discharge (2.5 volts). However, it is better not to let the batteries reach this state.

Graphite is used for the anode of such a battery. If the rules for using the part are not followed (for example, creating a very high charging current or low resistance), gas may begin to appear on the surface. The properties of manganese batteries described above indicate high quality and performance properties, which is why they outperform cobalt batteries.

Lithium iron phosphate species

Lithium iron phosphate batteries

Their second name is ferrophosphate. This type is rightfully considered the safest in comparison with other types of lithium-ion batteries. They have stable chemistry relative to other types. The battery design uses an iron phosphate cathode. It is non-toxic and resistant to high temperatures. Ferrophosphate species do not have a charge controller. They are capable of exploding or igniting only if severe damage to the body occurs, and even then, this is unlikely. The described batteries are immune to various manifestations of incorrect operation (creation of low resistance data).

18650 battery charging rules

Charging 18650 battery

When using 18650, the question arises about whether it is charging correctly. The procedure is very simple, but it must be done responsibly, avoiding negligence and violations of technology. Proper charging is key to long battery life.

Note! Completely discharging and fully charging has a detrimental effect on the condition of the battery. It is better to charge the battery to 90%.

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 a controller. This way the charging process will be the safest.

Currently, purchasing a charger is not a problem. The assortment of stores and retail outlets has a large number of devices from 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 of the 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. The reasonable price and real high capacity of the batteries made them the best seller among lithium-ion batteries of the 18650 type. 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 circuits and overcharging. 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.

It is difficult to find an area where there are no devices running on electrical energy. Mobile sources include rechargeable batteries and disposable batteries that power the consumer by converting chemical energy into electrical energy. Lithium-ion batteries are electron pairs with active components containing lithium salts. The shape of the battery resembles a disposable AA battery, but is slightly larger, has hundreds of charging cycles, and belongs to Li-ion 18650 batteries.

Production of lithium-ion batteries is based on company sites Sanyo, Sony, Panasonic, LG Chem, Samsung SDI, Skme, Moli, BAK, Lishen, ATL, HYB. Other companies buy elements, repackage them, passing them off as their own products. They also write false information about the product on the shrink film. There are currently no 18650 Li-ion batteries with a capacity higher than 3600 mAh.

The main difference between rechargeable batteries and batteries is the possibility of repeated recharging. All batteries are designed for a voltage of 1.5 V, the product has a li-ion output of 3.7 V. Form factor 18650 means a lithium battery 65 mm long, 18 mm in diameter.

18650 lithium battery operating mode characteristics:

• The maximum voltage is 4.2 V, and even minor overcharging significantly reduces the service life.
• The minimum voltage is 2.75 V. When reaching 2.5 V, special conditions for capacity restoration are required. When the voltage at the terminals is 2.0 V, the charge is not restored.
• The minimum operating temperature is -20 0 C. Charging at sub-zero temperatures is not possible.
• Maximum temperature +60 0 C. At higher temperatures, an explosion or fire can be expected.
• Capacity is measured in Amps/Hours. A fully charged 1Ah battery can supply 1A of current for an hour, 2A for 30 minutes, or 15A for 4 minutes.

Charge controller for li-ion battery 18650

Major manufacturers produce standard 18650 lithium batteries without a protective board. This controller, made in the form of an electronic circuit, is installed on top of the case, lengthening it somewhat. The board is located in front of the negative terminal and protects the battery from short circuits, overcharging, and overdischarging. Defense is being assembled in China. There are devices of good quality, but there are outright scams - unreliable information, capacity 9,000A/h. After installing the protection, the case is placed in shrink film with inscriptions. Due to the additional design, the case becomes longer and thicker, and may not fit into the intended slot. Its standard size can be 18700, and can be increased due to additional actions. If the 18650 battery is used to create a 12V battery that has a common charge controller, breakers on the individual Li-ion cells are not needed.

The purpose of protection is to ensure the operation of the energy source within the specified parameters. When charging with a simple charger, the protection will not allow overcharging and will turn off the power in time if the 18650 lithium battery runs down to a voltage of 2.7 V.

Marking of lithium batteries 18650

There are markings on the surface of the battery case. Here you can find complete information about the technical properties. In addition to the manufacturing date, expiration date and manufacturer's brand, the device of 18650 lithium batteries and the consumer qualities associated with this aspect are encrypted.

1. ICR – lithium-cobalt cathode. The battery has a high capacity, but is designed for low current consumption. Used in laptops, video cameras and similar long-lasting equipment with low energy consumption.
2. IMR– lithium-manganese cathode. It has the ability to produce high currents and can withstand discharge up to 2.5 a/h.
3. INR – nickelate cathode. Provides high currents, withstands discharge up to 2.5 V.
4. NCR – Panasonic specific markings. The properties of the battery are identical to the IMR. Nickelates, cobalt salts, and aluminum oxide are used.

Positions 2,3,4 are called “high-current”, they are used for flashlights, binoculars, and cameras.

Lithium ferrophosphate batteries have the ability to operate at deep minus temperatures and are restored during deep discharge. Undervalued on the market.

By the marking you can determine whether this is a rechargeable lithium battery with the letters I R. If there are letters C/M/F, the cathode material is known. The capacity indicated will be mA/h. The release date and expiration date are located in different places.

You should know that manufacturers of rechargeable lithium batteries do not have products with a capacity of more than 3,600 mAh. In order to repair a laptop battery or assemble a new one, you need to purchase batteries without protection. To use a single copy, you need to buy elements with protection.

How to test a 18650 lithium battery

If, when buying an expensive device, you doubt the veracity of the information on the case, there are ways to check. In addition to special meters, you can use improvised means.

• You have a charger, you can time the time of full charging with a certain current strength. The product of time and current will reveal the approximate capacity of the li-ion battery.
• A smart charger will help you. It will show both voltage and capacity, but the device is expensive.
• Connect the flashlight, measure the current, and wait for the light to go out. The product of time and current gives the current capacity in A/h.

You can determine the power of a battery by weight: a 18650 lithium battery with a capacity of 2000 mAh should weigh 40 g. The higher the capacity, the greater the weight. But the defectors have learned to add sand to the body to make it heavier.

Charger for 18650 lithium batteries

Lithium batteries are demanding on terminal voltage parameters. The maximum voltage is 4.2 V, the minimum is 2.7 V. Therefore, the charger works as a voltage stabilizer, creating 5 V at the output.

The determining indicators are the charging current and the number of elements in the battery, which you set yourself. Each element (jar) must receive a full charge. Power is distributed using a balancer circuit for 18650 lithium batteries. The balancer can be built-in or manually controlled. Good memory is expensive. Anyone who understands electrical circuits and knows how to solder can make a charger for li-ion with their own hands.

The proposed do-it-yourself charger circuit for 18650 lithium batteries is simple and will turn off the consumer after charging on its own. The cost of components is about 4 dollars, not a shortage. The device is reliable, will not overheat and will not catch fire.

Charger circuit for lithium 18650 batteries

In a homemade charger, the current in the circuit is regulated by resistor R4. The resistance is selected so that the initial current depends on the capacity of the 18650 lithium battery. What current should be used to charge a li-ion battery if its capacity is 2,000 mAh? 0.5 - 1.0 C will be 1-2 amperes. This is the charging current.

What current to charge a li-ion battery 18650

There is a procedure for restoring the functionality of a 18650 lithium battery after the voltage drops to working voltage. We restore capacity measured in amp hours. Therefore, first we connect the Li-ion battery form factor 18650 to the charger, then we set the charging current with our own hands. The voltage changes over time, the initial value is 0.5 V. As a stabilizer, the charger is designed for 5 V. To maintain performance, parameters of 40-80% of the capacity are considered favorable.

The charging scheme for a li-ion 18650 battery involves 2 stages. First, you need to raise the voltage at the poles to 4.2 V, then stabilize the capacitance by gradually reducing the current. The charge is considered complete if the current drops to 5-7 mA when the power is turned off. The entire charging cycle should not exceed 3 hours.

The simplest single-slot Chinese charger for li-ion 18650 batteries is designed for a charging current of 1 A. But you will have to monitor the process yourself, switch it yourself. Universal chargers are expensive, but they have a display and carry out the process independently.

How to properly charge a Li-ion 18650 battery in a laptop? Connecting a set of energy sources in the gadget via Pover Bank. The battery can be charged from the mains, but it is important to turn off the power as soon as the unit has reached capacity.

Restoring li-ion battery 18650

If the battery refuses to work, it may manifest itself as follows:

• The energy source is quickly discharged.
• The battery is dead and won't charge at all.

Any source can quickly discharge if the capacity is lost. This is precisely why overcharge and deep discharge are dangerous, from which protection is provided. But there is no escape from natural aging, when storage in a warehouse annually reduces the capacity of the cans. There are no methods of regeneration, only replacement.

What to do if the battery does not charge after a deep discharge? How to restore li-ion 18650? After the controller disconnects the battery, it still has a reserve of energy capable of delivering 2.8-2.4 V voltage at the poles. But the charger does not recognize a charge up to 3.0V; anything lower is zero. Is it possible to wake up the battery and start the chemical reaction again? What needs to be done to increase the charge of li-ion 18650 to 3.1 -3.3V? You need to use a way to “push” the battery, give it the necessary charge.

Without going into calculations, use the proposed circuit, mounting it with a 62 Ohm resistor (0.5 W). A 5V power supply is used here.

If the resistor heats up, the lithium battery is zero, which means there is a short circuit or the protection module is faulty.

How to restore a 18650 lithium battery using a universal charger? Set the charge current to 10 mA, and perform precharging as written in the instructions for the device. After raising the voltage to 3.1 V, charge in 2 stages according to the SONY scheme.

Which 18650 lithium batteries are better on Ali Express

If the cost and quality of a 18650 lithium battery is important to you, use the AliExpress resource. There are a lot of products here, from different manufacturers. The battery you are looking for is in demand and people like to counterfeit it. Therefore, it is necessary to know the main differences between a good model and a replica.

Be critical of the indicated capacity. Only the best manufacturers have achieved 3,600 A/h, the average ones have an indicator of 3000-3200 A/h. The protected battery is 2-3 mm longer and slightly thicker than the unprotected one. But if you are assembling a battery, protection is not needed, do not overpay.

High-quality products are more expensive here too. Please note that Ultrafire promises 9000 mAh, but in reality it turns out to be 5-10 times lower. It is better to use a product from a trusted manufacturer, and try to always buy the same brand of battery.

We suggest you look at the procedure for restoring a 18650 lithium battery

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.

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

There are three classes in total:

• LiCoO 2 or lithium cobalt;
• high-current lithium-manganese LiMnO 2, LiMn 2 O 4 and LiNiMnCoO 2;
• LiFePO 4 – lithium ferrophosphate.

Each type has its own advantages and disadvantages and is designed to perform specific tasks. LiCoO 2 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. LiFePO 4 are good in all respects, but are undervalued by the market. All 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;
• last digit ( 0 ) denotes the shape of the battery, in this case – cylinder.

Each battery manufacturer has its own specific markings.

Let's look at our own notations 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, laptop batteries, screwdrivers, portable handsets for landline phones, electronic cigarettes and even electric bicycles.

How to charge

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 the 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 how long it takes to charge the device. This depends on the battery capacity and its original condition.

Charging devices

Today buying 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.

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 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 battery operation it is necessary charge-discharge controller.

When assembling batteries, use 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 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.