Charging device. Chargers Dual 18650 Battery Charger

18650 batteries are used as the main power supply in many portable electronic devices. The advantage of rechargeable products is that one device can last for several years.

Unfortunately, such batteries are not without their drawbacks. The most noticeable disadvantages of such products are the high cost and dependence on chargers, which also cost a lot of money.

Contents

18650 charger for 2 - 4 batteries

Buying a charger for an 18650 battery is not difficult. The main thing you should pay attention to when choosing such a device is the number of compartments for placing batteries.

As a rule, such devices allow you to simultaneously charge from 2 to 4 cylindrical batteries. The most inexpensive devices can be designed for only 1 product.

The charger is powered from a 220 V electrical network, while a voltage of about 5 V with a current of 0.5 to 2.0 A is supplied to the output contacts of the device.

All products have a durable plastic case, on one side of which there are compartments for installing batteries.

One of the most inexpensive devices for charging 18650 batteries is the Fikida charger. This product is equipped with 4 slots, which are located in a compact plastic case. The low cost of the product is due to reduced manufacturing costs.

Unlike classic chargers, which are powered from a 220 V electrical network, Fikida allows you to effectively restore batteries from a USB connector. Thanks to this technical feature, it was also possible to minimize the dimensions and weight of the device.

The operating life of the charger has also been significantly increased. The device can operate from a universal USB adapter, as well as from the corresponding output of a computer or laptop.

Universal chargers

Universal devices can charge various li ion batteries. Many devices in this class have housings with 6 slots, which allows you to simultaneously install a large number of batteries.

Such devices are more expensive than conventional products, but thanks to the intelligent circuit, there is no need to additionally configure such devices. It is enough to install the batteries in the slots and the smart product will independently select the battery recovery mode.

You can purchase universal devices in stores that sell batteries and chargers for them, as well as on online trading platforms. When choosing, you should pay attention to the absence of mechanical damage to the body and packaging of such products.

Preference should be given to products made in Europe. Despite the higher price, such products can be equipped with additional functions that can extend the life of the batteries. For example, devices with a discharge function reduce the voltage at the battery terminals to 0.9 volts, which makes it possible to effectively combat such a negative phenomenon as the memory effect.

Semi-professional charging stations

If a 18650 battery charger is needed for daily use, then in order to ensure the highest level of quality in the recovery of rechargeable power supplies, it is recommended to purchase a semi-professional charging station. Almost all models of devices in this class have intelligent control and are designed to simultaneously charge up to 8 batteries.

One such lithium battery charger is the Polo P10. The charger of this model is designed for the simultaneous installation of 8 18650 batteries. The device allows you to automatically charge batteries of various brands.

Once the battery is restored to 100%, the electricity supply will stop completely. The absence of overcharging and overheating of batteries has a positive effect on their operation. Despite the presence of a large number of slots and an intelligent system, the device is relatively inexpensive, and the only drawback of the Polo P10 is the lack of a display.

The Golisi S4 charger also belongs to the category of semi-professional devices, but unlike the Polo P10, this product has only 4 slots for charging batteries. In terms of other parameters, the charger of this model is not inferior to the charger described above. The undoubted advantages of Golisi S4 include:

• Availability of digital display.
• The maximum charging current in the slot is 2 A (when charging 1 battery).
• Versatility.
• You can charge from a 12 Volt power source.

The only disadvantage of such a device is the relatively high cost, for example, the Polo P10 will cost 3 times less.

In general, a review of such products can take up more than one page, but even among the listed devices you can make a worthy choice.

Homemade chargers

If you have minimal skills in handling a soldering iron and radio components, as well as the necessary components and free time, you can independently make a charger for 18650 batteries. Such a product will not be inferior in its characteristics to factory samples.

The simplest circuit of a homemade charger consists of a 6-volt transformer and a diode bridge. To indicate power-on, an LED can also be added, which is connected to the output stage through a resistor.

Batteries

What current should I use to charge a li ion 18650 battery? How to properly use such a battery. What should lithium-ion power sources be afraid of and how can such a battery extend its service life? Similar questions can arise in a wide variety of electronics industries.

And if you decide to assemble your first flashlight or electronic cigarette with your own hands, then you definitely need to familiarize yourself with the rules for working with such current sources.

A lithium-ion battery is a type of electric battery that has become widespread in modern household and electronic equipment since 1991, after it was introduced to the market by SONY. As a power source, such batteries are used in cell phones, laptops and video cameras, as a current source for electronic cigarettes and electric cars.

The disadvantages of this type of battery start with the fact that the first generation lithium-ion batteries were a blast in the market. Not only literally, but also figuratively. These batteries exploded.

This was explained by the fact that a lithium metal anode was used inside. During the process of numerous charging and discharging of such a battery, spatial formations appeared on the anode, which led to the short circuit of the electrodes, and as a result, to a fire or explosion.

After this material was replaced by graphite, this problem was eliminated, but problems could still arise on the cathode, which was made of cobalt oxide. If operating conditions are violated, or rather recharging, the problem could recur. This was corrected with the introduction of lithium ferrophosphate batteries.

All modern lithium-ion batteries prevent overheating and overcharging, but the problem of loss of charge remains at low temperatures when using devices.

Among the undeniable advantages of lithium-ion batteries, I would like to note the following:

• high battery capacity;
• low self-discharge;
• no need for maintenance.

Original chargers

The charger for lithium-ion batteries is quite similar to the charger for lead-acid batteries. The only difference is that the lithium-ion battery has very high voltages on each bank and more stringent voltage tolerance requirements.

This type of battery is called a can because of its external similarity to aluminum beverage cans. The most common battery of this shape is 18650. The battery received this designation due to its dimensions: 18 millimeters in diameter and 65 millimeters in height.

If for lead-acid batteries some inaccuracies in indicating the limit voltages during charging are acceptable, with lithium-ion cells everything is much more specific. During the charging process, when the voltage increases to 4.2 Volts, the supply of voltage to the element should stop. The permissible error is only 0.05 Volt.

Chinese chargers that can be found on the market can be designed for batteries made from different materials. Li-ion, without compromising its performance, can be charged with a current of 0.8 A. In this case, you need to very carefully control the voltage on the bank. It is advisable not to allow values ​​above 4.2 Volts. If the assembly with the battery includes a controller, then you don’t need to worry about anything, the controller will do everything for you.

The most ideal charger for lithium-ion batteries will be a voltage stabilizer and current limiter at the beginning of the charge.

Lithium must be charged with a stable voltage and limited current at the beginning of the charge.

Homemade charger

To charge the 18650, you can buy a universal charger, and not worry about how to check the necessary parameters with a multimeter. But such a purchase will cost you a pretty penny.

The price for such a device will vary around $45. But you can still spend 2-3 hours and assemble the charger with your own hands. Moreover, this charger will be cheap, reliable and will automatically turn off your battery.

The parts that we will use today to create our charger are available to every radio amateur. If there is no radio amateur with the necessary parts at hand, then on the radio market you can buy all the parts for no more than 2-4 dollars. A circuit that is assembled correctly and installed carefully starts working immediately and does not require any additional debugging.

Electrical circuit for charging a 18650 battery.

In addition to everything, when you install the stabilizer on a suitable radiator, you can safely charge your batteries without fear that the charger will overheat and catch fire. The same cannot be said about Chinese chargers.

The scheme works quite simply. First, the battery must be charged with a constant current, which is determined by the resistance of resistor R4. After the battery has a voltage of 4.2 Volts, constant voltage charging begins. When the charging current drops to very small values, the LED in the circuit will stop lighting.

The currents recommended for charging lithium-ion batteries should not exceed 10% of the battery capacity. This will increase the life of your battery. If the value of resistor R4 is 11 Ohms, the current in the circuit will be 100 mA. If you use a 5 Ohm resistance, the charging current will be 230 mA.

How to extend the life of your 18650

Disassembled battery.

If you have to leave your lithium-ion battery unused for some time, it is better to store the batteries separately from the device they power. A fully charged element will lose some of its charge over time.

An element that is charged very little, or discharged completely, may permanently lose its functionality after a long period of hibernation. It would be optimal to store the 18650 at a charge level of about 50 percent.

You should not allow the element to be completely discharged and overcharged. Lithium-ion batteries have no memory effect at all. It is advisable to charge such batteries until their charge is completely exhausted. This can also extend the life of the battery.

Lithium-ion batteries do not like either heat or cold. The optimal temperature conditions for these batteries will be the range from +10 to +25 degrees Celsius.

Cold can not only reduce the operating time of the element, but also destroy its chemical system. I think each of us has noticed how the charge level in a mobile phone quickly drops in the cold.

Conclusion

Summarizing all of the above, I would like to note that if you are going to charge a lithium-ion battery using a store-made charger, pay attention to the fact that it is not made in China. Very often, these chargers are made from cheap materials and do not always follow the required technology, which can lead to undesirable consequences in the form of fires.

If you want to assemble the device yourself, then you need to charge the lithium-ion battery with a current that will be 10% of the battery capacity. The maximum figure may be 20 percent, but this value is no longer desirable.

When using such batteries, you should follow the rules of operation and storage in order to exclude the possibility of an explosion, for example, from overheating, or failure.

Compliance with the operating conditions and rules will extend the life of the lithium-ion battery, and as a result, save you from unnecessary financial costs. The battery is your assistant. Take care of her!

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

Of the huge variety of li-ion batteries, the 18650 battery is especially in demand. Long service life and stable battery parameters are ensured by compliance with a number of rules, but the main condition affecting the performance of 18650 lithium-ion batteries is their correct charging.

18650 battery

The main positive characteristics of 18650 lithium batteries are the ability to accumulate a large amount of charge, store this charge for quite a long time, the lack of memory properties and a meager specific gravity.

The memory effect is primarily characteristic of nickel-cadmium batteries. This effect means some loss of battery capacity if it is charged until it is completely discharged.

For 18650 battery and othersli-ion batteries has its own marking:

• The first two digits indicate the diameter in millimeters;
• The next two numbers indicate the length in millimeters;
• The last digit indicates the type of battery (0 indicates the cylinder).

At the initial stage of production and use, such batteries were explosive due to uncontrolled chemical reactions inside and cases of short circuits inside the batteries. To prevent such breakdowns, all rechargeable batteries in general and 18650 batteries in particular are equipped with special boards with controllers that prevent damage to the battery due to critical overheating and depressurization.

Optimal storage conditions for lithium-ion batteries are achieved at a temperature of 5°C with a 40% battery discharge.

How to charge a 18650 battery

Well-known charger manufacturers use a two-stage battery charging method.

The two-stage charging method includes:

1. The task of the charger at the first stage is reduced to charging with a stabilized current. The charging current is determined by the nominal capacity of the battery with a coefficient of the order of 0.2 to 0.5. During charging, the voltage automatically increases to maintain a stable current. At a voltage of 4.2V, the charging process stops at this stage. By this point, the battery manages to replenish its capacity by 70-80%. In order to reduce charging time, a rapid charging process is used for lithium batteries. In this case, the charging current is taken with a coefficient of 0.5-1.0;
2. Charging 18650 in the second stage takes place with a constant voltage. The 18650 charging board supports Ucharge ~ 4.15-4.25V and controls the current value. The current value during charging gradually decreases to a value of 0.05-0.01 of the battery capacity. Accordingly, the charging process is considered complete.

In addition to the above-mentioned charging stages, a preparatory battery charge is applicable for 18650 li-ion batteries. Charging is carried out with a reduced current until the voltage on the battery reaches 2.8V.

Despite its indispensability, the two-stage charging system has some disadvantages. Since the voltage on the battery is measured while a large charging current passes through it, depending on the internal resistance of the battery, such measurements may vary. In this regard, the voltage can reach 4.3-4.4V, which has an extremely negative effect on the battery. In practice, it is better to use chargers with current pulses if there are gaps between them. During these intervals, the voltage on the battery is measured. The closer the voltage is to the value of a fully charged battery, the shorter the pulse the charger produces. Accordingly, when the measured voltage reaches 4.15V, the supply of pulses will stop.

Charger circuits

Radio amateurs quite often wonder how to charge lithium-ion batteries and how to charge with maximum savings of resources, effort and time. The presence of the necessary element base and basic knowledge will not leave the radio amateur without a charger.

The assembled DIY 18650 charger, shown in the picture below, is adjusted by setting the output voltage to 4.2V with trimming resistor R8 and the charging current with resistors R4, R6. The charging process is considered complete after the HL1 LED goes out.

Important! For normal operation of the LM317 chip, charging for 18650 batteries must have an input voltage in the range of 8-12V.

Homemade charging for 18650, which contains MAX integrated circuits (1551 or 1555), is qualitatively different from its competitors in a number of properties and features:

• Ability to charge the battery from USB or from a separate power supply;
• No external transistors and diodes;
• Protection against excessive overheating by artificially reducing the charging current.

It will not be difficult to obtain a pulse charger for 18650, assembled with your own hands, due to the absence of a microcircuit in the device. The presented charger for 18650 fulfills all the requirements and functions of pulse charging. An additional advantage of the charger is the ability to replace the element base with domestic analogues. A smart charger for 18650 batteries, assembled and tested with your own hands, will last no worse than the purchased charger.

The presented topic revealed the following questions: how to charge the battery, how to charge a li-ion battery. When using a charger for 18650 batteries, purchased or homemade, the main thing is to carefully check the output values. Next, you can pay attention to additional options in the form of LCD displays, the number of channels, the presence of backlight, and a car adapter.

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