If your laptop battery no longer lasts the same time without recharging, it's time to take care of buying a new battery. How to choose the right product, what you should pay attention to and how to increase battery life - we will consider further.
Appearance of the battery model 18650
This type is intended for use primarily in laptops. The Chinese lithium 18650 battery is packed in a soft stretch bag. Diameter - 17.5 - 18 mm, weight - about 50 g, length - up to 69 mm.
Equipped with inscriptions of power in volts and mAh. Models may vary in cost and quality. Let's consider some of them.
Top 5 batteries from Aliexpress
Consider the most popular models:
- 2000 mAh;
- 2200 mAh;
- 2600 mAh;
- 3400 mAh;
- 5000 mAh
The maximum capacity is 3400 mAh. Therefore, the latter model is of dubious provenance.
All models are not protected, as their length does not exceed 65 mm. That is, they cannot be used in devices without discharge control, because fire is possible.
Scope of application of batteries
Such batteries can be used to restore power to laptops, electronic cigarettes, flashlights, restore performance, or convert screwdrivers to lithium.
How to charge such a battery?
New batteries do not have a full capacity, for best performance results they are advised to "swing" - charge and discharge two or three times.
You can use one of the universal chargers for this process. Secure the battery in the holder. Instead of a positive contact, you can use a thick narrowed copper wire, the spring can also be shunted to reduce resistance losses.
There are multi-ampere powerful batteries that are characterized by high productivity rates.
The process of discharging and charging will take place under a current of 800 mA. In total, one cycle takes from 6 to 8 hours. There can be three such stages.
How did the batteries react to testing?
This table shows the results of the experiment on the five most popular battery models.
Battery operation
18650 charging is found in many devices where the use of simple batteries is not enough. Can withstand up to 1000 charge-discharge processes.
By 18650 charging, you can purchase cases that allow you to connect several batteries into one large one. By connecting several cells in parallel, you can get one battery with a capacity equal to the total amount, but with a voltage that is no more than one battery.
The higher the capacity, the longer such a device will work.
If you connect several batteries in series, the voltage will add up, and the capacity will remain equal to one battery. A good example is a case that outputs about 12 watts depending on
You can use the device to illuminate a bicycle, a suit with flexible neon LEDs, as it allows you to "power" a lot of elements and a long cord length at the same time.
It is also beneficial to use a device based on 18650 charging to charge batteries.
Scope of application of 18650 battery
18650 charging can be used in different areas. For successful use, the battery must be “pumped” using a charger, the power supply of which has a power of up to 18 W, and check their capacity.
If you wind and test 4 batteries, then connect them using special plugs, you can get a more powerful device.
Choice of charger
The review is based on a comparison of the cost from the most budgetary to more expensive items.
The most inexpensive device is designed to use a single 18650 battery with a current of 1 ampere.
The second charging model for 18650 has two independent channels, the final voltage is 4.2 Volts. Almost the same as the first option. The length of the wire is 70 cm, it is convenient to get from the table to the outlet at different heights.
When connected to the network, green LEDs light up, which turn red when the battery is inserted. Once charging is complete, the LED will turn green, just like when charging is not required.
The third charge for 18650 is also affordable, with the previous option is almost in the same price range. Allows you to charge batteries of two sizes - 18650 and 26650. When placing the first option, small gaps are visible on the sides.
You can improve the box holder for the battery. The device charges with a current of 4.2 W at 600 mA. The light glows directly on the charger, when it is turned on, it changes color from green to red.
The fourth charging option 650 is more versatile than the previous ones, as it allows the use of a variety of standard sizes. This model is compact, takes up little space and is easy to carry in a bag.
The downside of the device is the plug, which does not fit every outlet. An additional adapter is required. The final voltage of this 650 charge is 4.2W with a charge current of 450mA. If there is a higher voltage, the battery will quickly fail.
The fifth option is a universal one capable of charging the following types of batteries:
- Lithium.
- Nickel metal hydride.
- Nickel-cadmium.
- Lead.
This 18650 battery charger is very convenient, but if you need to charge several models, you will not see information specifically for each option.
Another item to review is the VT-S3100. It has four independent channels, each of which can charge or discharge batteries of different sizes. This 18650 battery charging model is well-deservedly popular with users.
Battery selection rules
How and with what can you charge 18650? For successful operation of the device, it is necessary to choose its variant correctly.
To charge the 18650 battery, you need a charger built on the TP 4056 chip. Its advantage is that it is a completely ready-to-connect and work device.
Two LED indicators signal the status of the charging process. As soon as the battery is charged, another color immediately turns on. If you solder two wires and use the connector to connect any power source, you can improve the quality of recharging.
The charge current is set by a resistor installed in the standard position. The charge current is 1 ampere. You can remove this resistor and replace it with a different value. It will depend on the desired current strength. It is optimal to choose a model for 10 kOhm. You need to solder it in place of the old resistor.
To check the quality of recharging, you can take a regular 5W power supply and a mini-USB cable and connect them together for charging to the network. The other end of the cable goes to the charger. The process is running successfully. In the same way, you can charge batteries from laptops, phones, tablets.
In operation, the charger for 18650, whose dimensions are compact, shows good performance.
It is important to observe the polarity and be very careful in this. The current strength should not exceed the capacity of the battery.
The minimum current should be 1/10 of the volume. Then you can save the capacity of the device, performance and durability of operation.
Knowing the rules of how to charge the 18650, you can successfully complete this process.
Models with protection board
18650 batteries from the Japanese company PANASONIC have an average cost of $40 for 6 pieces.
Such products can be used for laptop charging banks and in flashlights. It is important to consider the release date and the originality of the production.
These models have a protective board approximately 2 mm thick. It is necessary, since any battery can be over-discharged. Protection protects the device from such an action so that the voltage threshold is not exceeded.
As soon as the battery reaches the allowable limits of 4.25 W, the protection board disables recharging and the process stops.
At a voltage of 2.75 watts, the battery will simply stop functioning. When discharged below this voltage, the board will break the charging circuit.
Short circuit protection is also provided. As soon as the current reaches a voltage of 7.5 A, the system will open this circuit.
These precautions greatly extend the life of the batteries. If it is heavily discharged, below 2.5 W, the device may go into "sleep mode", in which either the resource will decrease or it will no longer function.
When testing the performance of this model, good results can be noted.
Possible errors in the process of using batteries
It is sometimes believed that 18650 sizes that are standard within the same type necessarily require several complete discharge cycles. Therefore, if done intentionally, the service life is reduced.
Capacity 18650 does not require mandatory discharge to zero.
Whatever the size of the battery bank, its nominal voltage level is always standard and is 3.7 watts. The advancement of new technologies helps eliminate the “memory effect” in batteries in order to improve the current-voltage characteristics and increase the capacity of the battery.
Summing up
The 18650 battery is a kind of lithium-ion models. They can be purchased wholesale and retail, depending on the purpose of operation.
The modern battery market is represented by both budget and more expensive models. Batteries can be protected and without special protection.
According to user reviews, models from Japanese manufacturers deserve the most popularity. When purchasing such a product, it is necessary to clarify the date of manufacture and the originality of the product.
Lithium batteries (Li-Io, Li-Po) are currently the most popular rechargeable sources of electrical energy. The lithium battery has a nominal voltage of 3.7 volts, which is indicated on the case. However, a 100% charged battery has a voltage of 4.2 V, and a discharged “to zero” voltage is 2.5 V, it makes no sense to discharge the battery below 3 V, firstly, it deteriorates from this, and secondly, in the range from 3 to 2.5 The battery gives only a couple of percent of the energy. Thus, we accept the operating voltage range of 3 - 4.2 Volts. You can watch my selection of tips on the operation and storage of lithium batteries in this video.
There are two options for connecting batteries, series and parallel.
When connected in series, the voltage on all batteries is summed up, when a load is connected, a current equal to the total current in the circuit flows from each battery, in general, the load resistance sets the discharge current. You should remember this from school. Now the fun part, capacity. The capacity of the assembly with such a connection is good equal to the capacity of the battery with the smallest capacity. Imagine that all batteries are 100% charged. Look, the discharge current is the same everywhere, and the battery with the smallest capacity will be discharged first, this is at least logical. And as soon as it is discharged, it will no longer be possible to load this assembly further. Yes, the rest of the batteries are still charged. But if we continue to remove the current, then our weak battery will begin to over-discharge, and fail. That is, it is correct to assume that the capacity of a series-connected assembly is equal to the capacity of the smallest or most discharged battery. From this we conclude: it is necessary to assemble a serial battery, first of all, from batteries of the same capacity, and secondly, before assembly, they must all be charged equally, in other words, 100%. There is such a thing, called BMS (Battery Monitoring System), it can monitor each battery in the battery, and as soon as one of them is discharged, it disconnects the entire battery from the load, this will be discussed below. Now as for charging such a battery. You need to charge it with a voltage equal to the sum of the maximum voltages on all batteries. For lithium this is 4.2 volts. That is, we charge a battery of three with a voltage of 12.6 V. See what happens if the batteries are not the same. The battery with the smallest capacity will charge the fastest. But the others haven't loaded yet. And our poor battery will fry and recharge until the rest are charged. Overdischarge, I remind you, lithium also does not like very much and deteriorates. To avoid this, we recall the previous conclusion.
Let's move on to parallel connection. The capacity of such a battery is equal to the sum of the capacities of all the batteries included in it. The discharge current for each cell is equal to the total load current divided by the number of cells. That is, the more batteries in such an assembly, the more current it can give. But with tension, an interesting thing happens. If we collect batteries that have different voltages, that is, roughly speaking, charged to different percentages, then after connection they will begin to exchange energy until the voltage on all cells becomes the same. We conclude: before assembly, the batteries must again be charged in the same way, otherwise large currents will flow when connected, and the discharged battery will be damaged, and most likely it may even catch fire. In the process of discharging, the batteries also exchange energy, that is, if one of the cans has a lower capacity, the rest will not allow it to discharge faster than themselves, that is, batteries with different capacities can be used in a parallel assembly. The only exception is high current operation. On different batteries under load, the voltage sags differently, and current will start to run between the “strong” and “weak” batteries, and we don’t need this at all. And the same goes for charging. You can absolutely safely charge batteries of different capacities in parallel, that is, balancing is not needed, the assembly will balance itself.
In both cases considered, the charging current and the discharging current must be observed. The charging current for Li-Io should not exceed half the battery capacity in amperes (1000 mah battery - charge 0.5 A, battery 2 Ah, charge 1 A). The maximum discharge current is usually indicated in the datasheet (TTX) of the battery. For example: laptop 18650 batteries and batteries from smartphones cannot be loaded with a current exceeding 2 battery capacities in Amperes (example: 2500 mah battery, which means you need to take a maximum of 2.5 * 2 = 5 Amperes from it). But there are high-current batteries, where the discharge current is clearly indicated in the specifications.
Features of charging batteries with Chinese modules
Standard purchased charging and protection module for 20 rubles for lithium battery ( Aliexpress link)
(positioned by the seller as a module for one can of 18650) can and will charge any lithium battery regardless of shape, size and capacity to the correct voltage of 4.2 volts (the voltage of a fully charged battery, to the eyeballs). Even if it is a huge 8000mah lithium package (of course, we are talking about one cell at 3.6-3.7v). The module gives a charging current of 1 amp, this means that they can safely charge any battery with a capacity of 2000mah and above (2Ah, which means the charging current is half the capacity, 1A) and, accordingly, the charging time in hours will be equal to the battery capacity in amperes (actually a little more, one and a half to two hours for every 1000mah). By the way, the battery can be connected to the load already during the charge.
Important! If you want to charge a battery with a smaller capacity (for example, one old 900mah can or a tiny 230mah lithium sachet), then 1A charging current is a lot, it should be reduced. This is done by replacing the resistor R3 on the module according to the attached table. The resistor is not necessarily smd, the most common one will do. I remind you that the charging current should be half the capacity of the battery (or less, it's not scary).
But if the seller says that this module is for one 18650 can, can it charge two cans? Or three? What if you need to assemble a capacious power bank from several batteries?
CAN! All lithium batteries can be connected in parallel (all pluses to pluses, all minuses to minuses) REGARDLESS OF THE CAPACITY. Batteries soldered in parallel maintain an operating voltage of 4.2v and their capacity adds up. Even if you take one can at 3400mah and the second at 900, you get 4300. Batteries will work as a whole and will be discharged in proportion to their capacity.
The voltage in the PARALLEL ASSEMBLY IS ALWAYS THE SAME ON ALL BATTERIES! And not a single battery can be physically discharged in an assembly before others; the principle of communicating vessels works here. Those who claim the opposite and say that batteries with a lower capacity will discharge faster and die - they are confused with SERIAL assembly, spit in their face. 
Important! Before connecting to each other, all batteries must have approximately the same voltage so that equalizing currents do not flow between them at the time of soldering, they can be very large. Therefore, it is best to simply charge each battery individually before assembly. Of course, the charging time of the entire assembly will increase, since you use the same 1A module. But you can parallelize two modules, getting a charging current of up to 2A (if your charger can give that much). To do this, you need to connect all similar terminals of the modules with jumpers (except for Out- and B +, they are duplicated on the boards by other nickels, they will already be connected anyway). Or you can buy a module ( Aliexpress link), on which the microcircuits are already in parallel. This module is capable of charging with a current of 3 Amperes.
Sorry to be so obvious, but people still get confused, so we'll have to discuss the difference between parallel and series.
PARALLEL the connection (all pluses to pluses, all minuses to minuses) keeps the battery voltage at 4.2 volts, but increases the capacity by adding all the capacitances together. All power banks use a parallel connection of several batteries. Such an assembly can still be charged from USB and the boost converter raises the voltage to the output 5v.
SEQUENTIAL connection (each plus to the minus of the subsequent battery) gives a multiple increase in the voltage of one charged can of 4.2v (2s - 8.4v, 3s - 12.6v, and so on), but the capacity remains the same. If three 2000mah batteries are used, then the assembly capacity is 2000mah.
Important! It is believed that for sequential assembly it is sacred that it is necessary to use only batteries of the same capacity. Actually it is not. You can use different ones, but then the battery capacity will be determined by the LOWEST capacity in the assembly. Add up 3000 + 3000 + 800 - you get an 800mah build. Then the specialists begin to crow that then a less capacious battery will discharge faster and die. And it doesn't matter! The main and truly sacred rule is that for sequential assembly, it is always necessary to use a BMS protection board for the required number of cans. It will determine the voltage on each cell and turn off the entire assembly if one is discharged first. In the case of a bank of 800, it will be discharged, the BMS will disconnect the load from the battery, the discharge will stop and the residual charge of 2200mah on the remaining banks will no longer matter - you need to charge.
The BMS board, unlike the single charger module, IS NOT A SERIAL CHARGER. Required for charging tuned source of the desired voltage and current. Guyver made a video about this, so don't waste your time, watch it, it's about it as thoroughly as possible.
Is it possible to charge a series assembly by connecting several single charging modules?
In fact, under certain assumptions, it is possible. For some homemade products, a circuit using single modules, also connected in series, has proven itself, but EACH module needs its own SEPARATE POWER SUPPLY. If you charge 3s - take three phone chargers and connect each to one module. When using a single source - power short circuit, nothing works. Such a system also works as a protection for the assembly (but the modules are capable of delivering no more than 3 amperes). Or, simply charge the assembly by the cell, connecting the module to each battery until it is fully charged.
Battery indicator 
It is also an urgent problem - at least to know approximately how much percent of the charge remains on the battery so that it does not run out at the most crucial moment.
For parallel assemblies at 4.2 volts, the most obvious solution would be to immediately purchase a ready-made power bank board, which already has a display showing charge percentages. These percentages are not super-accurate, but still help. The issue price is about 150-200 rubles, all are presented on the Guyver website. Even if you are not building a power bank, but something else, this board is quite cheap and small to place it in a homemade product. Plus, it already has the function of charging and protecting batteries.
There are ready-made miniature indicators for one or more cans, 90-100r 
Well, the cheapest and most popular method is to use the MT3608 boost converter (30 rubles), set to 5-5.1v. Actually, if you make a power bank on any 5-volt converter, then you don’t even need to buy anything. The refinement consists in installing a red or green LED (other colors will work at a different output voltage, from 6V and above) through a current-limiting resistor of 200-500 ohms between the output positive terminal (this will be a plus) and the input positive terminal (for an LED, this will be a minus). You are not mistaken, between two pluses! The fact is that during the operation of the converter, a voltage difference is created between the pluses, +4.2 and + 5V give a voltage of 0.8V between themselves. When the battery is discharged, its voltage will drop, and the output from the converter is always stable, which means the difference will increase. And when the voltage on the bank is 3.2-3.4V, the difference will reach the required value to light the LED - it starts to show that it's time to charge.
How to measure battery capacity?
We are already accustomed to the opinion that Imax b6 is needed for measurement, but it costs money and is redundant for most radio amateurs. But there is a way to measure the capacity of a 1-2-3-cell battery with sufficient accuracy and cheaply - a simple USB tester.
A detailed description of 18650 lithium-ion batteries, making a do-it-yourself charging device, application nuances.
TEST:
To understand if you have enough information about a lithium-ion battery:- What was the main drawback of the first 18650 battery models?
a) They exploded due to metallic lithium inside - with frequent charges, accumulations appeared on the element, leading to an explosion.
b) The battery was too bulky and inconvenient.
- What problem have manufacturers of modern 18650 models not yet got rid of?
a) The battery often overheats.
b) The battery quickly loses its charge when exposed to negative temperatures.
- In what temperature range is it desirable to store the battery?
a) + 10 - + 25 - ideal indicators. The battery does not tolerate too cold or hot rooms.
b) Store the battery at low temperatures when not in use.
c) At a temperature of + 30-45 degrees.
- Why can't I buy a charger made in China?
a) The case is too unreliable.
b) Parts of low quality, correct assembly technology is not always observed.
- At what charge level should the battery be stored?
a) Storage of 18650 should be carried out at a charge level that does not fall below 50%. Complete discharge cannot be performed.
b) Not less than 10%.
Answers:
- a) The main drawback of the first models is explosiveness. Lithium metal overgrown with growths during frequent charging and a short circuit occurred, leading to an explosion of the battery.
- b) Modern batteries do not tolerate low temperatures well - the charge drops very quickly.
- a) + 10 - + 25 - ideal indicators. Do not place the battery in other conditions.
- b) Chinese manufacturers often use low-quality parts when assembling devices, so they fail. The correct assembly technology is not always followed.
- a) If you plan to keep the battery out of work for a long time, then make sure that the charge on it does not fall below 50%, otherwise the battery will deteriorate.
Li-ion owners batteries 18650 are faced with the question of how much current to charge it. There are also difficulties in the correct operation, people do not know exactly what such batteries are afraid of, how to increase the duration of their work.
To independently assemble an electronic cigarette or a flashlight, you definitely need to study all aspects work with lithium-ion power supply.
Definition: Li-ion battery is a battery of electric current, which has become widespread among consumer electronics since 1991. It was this year that Sony Corporation presented the product to a wide market.
Answers to 5 frequently asked questions
- What are lithium-ion batteries used for?
- As a power source. Such batteries are often used for various mobile phones, camcorders, laptops, for recharging electric vehicles or modern electronic cigarettes.
- Do models have flaws?
- The main drawback of the model was that the first developments literally exploded. This is due to the fact that manufacturers have placed inside the anode, consisting of metallic lithium. When a large number of charges and discharges occur, formations appear on the anode, leading to a short circuit of the electrodes. The result is a fire, and then an explosion. This issue has been resolved for now.
- How was the explosion problem solved?
- To secure the design, the scientists replaced the core with graphite, and got rid of the problem with explosions. But difficulties remained with the cathode caused by the cobalt oxide construction. If the operational characteristics were violated, then the explosions were repeated. That is why it was necessary to ensure that the device was not subjected to overcharging. It was extremely inconvenient for users to constantly monitor the level of charge and the developers had to modify the device again. Modern models are safe. When the developers began to use lithium-ferro-phosphate batteries, they managed to get rid of this problem. A modern device is produced in such a way that overcharging and overheating is impossible.
- Are current models flawed?
- The charge is lost if the battery is exposed to low temperatures.
- If the battery is not used for a long time, will it deteriorate?
- If you do not lower the level of rarefaction below 50%, then it will not deteriorate.
3 battery advantages
Li-ion accumulators have a number of positive aspects because of which they gained popularity:
- Very large capacity battery.
- Small self-discharge.
- No special maintenance required.
Charging - 5 nuances
Charger Look at the picture of the original charger device. A charger designed for lithium-ion batteries is very similar to a lead-acid type of battery. The difference is that the lithium-ion battery there are high voltages on each bank and severe voltage tolerance requirements.
This is interesting! The battery is called a "can" because of the similarity with aluminum cans, which produce soft drinks.
"Banks" Most Popular Items nutrition with this form - 18650. The battery received this name because of its size: diameter - 18 mm, height - 65 mm. When is lead-acid charging batteries, minor inaccuracies in voltage indications are allowed. But with lithium-ion devices, everything is much more specific. When it happens charger, and the voltage increases to 4.2 volts, the voltage to the element must be stopped immediately. The error is only 0.5 volts.
Chinese exercise There are a large number on the market Chinese chargers designed for batteries of different materials. Without compromising performance, ion batteries are charged with a current of 0.8 A. But the voltage in the bank will have to be very clearly controlled. When the value is 4.2 Volts, immediately stop charging. But in the event that the bank is embedded controller, then do not worry about it, because the device will do everything on its own.
Charging 4.2 Volts
As charger for a lithium-ion battery, a voltage stabilizer is used, current is limited at the very beginning of charging. It is necessary to use an exceptionally stable voltage, and limit the current at the very beginning of the charging process. Charging should be completed at the moment when the stable voltage is 4.2 volts, there is no current, or its value is very small - in the region of 5-7 mA.
Oxidation When a rod of graphite, then the voltage should not exceed 4.1 V per cell. If this rule is neglected, the energy density will increase greatly, and the oxidation processes of the device will begin. As a result, the battery will fail. To avoid oxidation, modern models are equipped with additives - graphite not in pure form. But similar models can still be found by chance.
How to properly charge Li-ion batteries. Parallel connection of batteries.
Homemade charger at home (do it yourself) - 1 diagram
For charging 18650 they acquire universal charging, and constantly use a multimeter to find out the necessary parameters. But such a device is quite expensive. The minimum price is 2700 rubles.
Instead, you can spend just a few hours and assemble a charger device on one's own. The advantages of such an assembly are low cost, reliability, automatic battery shutdown. All parts used for assembly can be found in the garage of any radio amateur. If something is missing, it can be bought at the nearest radio store. You will have to spend a maximum of 300 rubles on components.
If scheme correctly assembled, then there is no need for additional configuration - it will immediately be ready for use.
You need to use the following wiring diagram:
Scheme
The good news is that if you set stabilizer to the desired radiator, then the battery is charged without fear that the charge will light up. And this definitely cannot be said about Chinese chargers, which sin with this unpleasant consequence.
The principle of operation - 4 nuances
- to start battery must be charged using direct current, which is determined by the resistance of the resistor R4;
- after battery will receive a voltage of 4.2 volts, the device switches to DC charging;
- when the current drops to the minimum values, the LED will stop burning;
- current that recharges the lithium-ion battery, should not exceed 10% of the total battery capacity. Thus, the service life of the batteries is increased. If the resistor R4 has a rating of 11 ohms, then the circuit current should be 100 mA. If the resistance is 5 ohms, then the charging current should be 230 mA.
It is also important to know 3 nuances about "life extension" 18650
- If battery will need to be left without work for some time, then it is advisable to store the batteries separately from the device that they will power. If the cell is fully charged, then over time it will lose some of its charge. In the case when the element is charged very little, or completely discharged, then the performance may completely disappear. This is especially noticeable during a long hibernation.
- Storage 18650 should be carried out at a charge level that does not fall below 50%. Under no circumstances should the cell be fully charged and recharged. This equipment has no memory effect. Charging must be done before the charge runs out completely. Thus, battery life will be extended.
- Battery it is forbidden to leave in too cold or hot rooms. A suitable storage temperature is + 10 - + 25 degrees Celsius. If you place the battery in the cold, then not only will the operating time be reduced, but the chemical system will also deteriorate. Everyone must have noticed that when using a mobile phone in winter, the charge batteries drops sharply.
How to avoid 4 mistakes when using and charging a lithium-ion battery
- In the event that you decide to recharge the lithium-ion battery using a store charge, you will have to make sure that it is not made in China. Typically, such devices are assembled from the cheapest materials, and the required technology is not always observed in them. As a result, this can lead to very sad consequences: fire and explosion.
- If you wish to assemble device, then you need to use a current to charge the battery, which is 10% of the battery capacity. The percentage may be higher, but not exceed 20%.
- When using ion batteries, do not violate the rules of storage and operation, otherwise overheating, fire and explosion may occur.
- If you follow all the rules operation, as well as the correct storage conditions, then the battery life will be extended.
Top 3 Best 18650 Battery Chargers
For high-quality battery charging, you should purchase good devices, which is already loved by many users.
- Nitecore Digicharger D4 - suitable for charging multiple batteries at once. Extremely easy to use.
- Nitecore i2 is one of the best options for modern devices. Clear and easy to use.
- Basen B21 is a universal device for different types of batteries.
Among Li-Ion batteries, the 18650 battery is especially popular. Its scope is very wide: such elements can be found in battery bundles of laptops, screwdrivers, in mechanical mod devices designed to power electronic cigarettes or household flashlights. They can be found in portable handsets of landline telephones. Also recently, the conversion of a screwdriver to lithium batteries of this particular type is gaining popularity, due to the fact that they work much longer than the elements of the previous generation.
When an 18650 battery is inserted into a particular device, how to charge it correctly and for how long are questions that any responsible owner of a household appliance with such batteries will ask.
A little about lithium-ion batteries
Since this battery is a kind of Li-Ion battery, it should be mentioned that these cells are now quite high. For lithium batteries 18650, as well as for other batteries with lithium in the composition, it is characteristic high capacity and ability to hold a charge for a long time .
By the way, this battery won its popular designation on the Internet due to its parameters: its diameter is 18 millimeters and its height is 65, which is quite convenient and compact, given its wide capabilities.
Previously, most of these batteries were characterized by increased explosiveness, in the literal sense of the word. The reason was a certain type of chemical reaction that occurred during the overheating of the elements at high temperatures. There was also a mechanical short circuit inside one or more "cans", which led to ignition.
Now all batteries of this type are equipped with special devices with a controller as part of the circuit, which prevents critical overheating and explosion. This device can be found in any 18650 battery if you carefully open it and see what is inside.
If such elements are not used for a long time and left discharged, they can quickly lose their properties. Therefore, charging 18650 should be carried out regularly, while a certain scheme must be observed. For example, you need to know what current to charge Li-Ion, or what voltage should be used to charge 18650 so that they do not overheat and fail prematurely.
How to charge 18650 battery
Before moving on to the topic of the charger, you need to outline the basic principles of charging for lithium 18650 batteries.
There are always a lot of "chargers" on sale, and many of them are universal, but the basic rules for lithium-ion batteries should be as follows:
- Charging starts with a voltage of 0.05 V, and the process should end when U rises to 4.2 V. It is important to remember that this is the allowed maximum, safe for batteries.
- Charge current: allowed to charge the battery at rates of 0.5 A and 1 A. At 1 A, the process will be much faster, but since a smoother current is recommended for any batteries charge Li, the best indicator is 0.5 A. Of course, if the batteries need to be charged urgently, the current level can be increased to 1 A. But in normal cases, you should not accelerate unnecessarily charging.
- The time it takes to charge battery, should not exceed three hours - so as not to damage the internal chemical structure of the battery, causing it to overheat.
- If your device is equipped with an automatic charging control system , it itself "knows" how long to charge the battery.
- On some chargers (both purchased and homemade) there is no such control , therefore, in this case, you will have to control the entire process yourself.
Which device should be used
Popular electronics stores offer a wide range of suitable chargers. In the cheapest, with a current level of 1 amp, you can put one 18650 battery.
There is a more advanced version with two "sockets" for cells, with a maximum voltage rating of 4.2 V . This charger for the 18650 is already a little more expensive, but it comes with a charge level indicator that controls how long the battery should be charged.
There is also a similar option, with the same characteristics - not only 18650 elements, but also 26650 models can be inserted into it.
Can be purchased and universal charger , which is suitable for all types of batteries, from nickel-cadmium to lithium-ion.
There are enough chargers, and most of them are equipped with both indicators and a safety system that eliminates the need to constantly check the level of voltage or current. Of course, the quality of the charger directly depends on how much money will be spent on it.
If you have the ability, time and desire not to spend money on buying a charger, you can make it yourself - of course, this will require a certain scheme.
How to charge a lithium-ion battery yourself
It is quite possible to make a charger for 18650 batteries with your own hands. The main thing is to know the basic principles of the electrical circuit and those indicators at which you can charge the battery.
Method number 1
The easiest way to recharge the battery in an emergency is to simply use an old but working charger from a Nokia or Samsung phone. Fortunately, the current and voltage parameters in such chargers will not harm the battery.
The scheme is simple, and even a schoolboy can handle it:
- At charging, you need to release the wires from the sheath connecting them, disconnect them into positive and negative poles . Usually the red posting is a plus, and the black one is a minus, so there should be no confusion.
- Now you just need to attach the battery to the bare contacts of the wiring with plasticine .
- Observing the polarity, connect the device to the network or to a computer - and the element can be safely charged, from time to time monitoring the process.
When asked how long to keep the battery on such an “express charger”, the answer is simple: an hour would be enough in order to restore the parameters of its capacity.
Method number 2
How to make charging a more perfect type? Here the circuit can be a little more complicated, given that you will have to use improvised tools in the form of a soldering iron, solder, glue and flux. However, the most important item that a home charger will need can be purchased from AliExpress - this is charging board. Therefore, it will not be difficult to assemble such a device on your own.
The scheme is this: Pthe armor is soldered to a pre-prepared plastic box with two wires ("pl yus" and "minus"). The battery will be in the box while charging. The box itself can be removed from any household appliance that has failed: it can be an old charger or a toy. The main thing is that the dimensions of the box correspond to the elements of 18650.
Soldering shouldn't be a problem. the board shows the places where the wires should be soldered . In addition, the board itself is already pre-equipped with two red and green LED indicators that will signal the charge level.
The board should be carefully glued to the box in any convenient place, then solder the wires, not forgetting to observe the polarity. Before soldering, the wires will need to be lightly stripped and tin with rosin and drop a little liquid flux (or solder) onto the board. It is important to ensure that the wiring does not short circuit with each other.
Such a scheme makes it possible to manufacture a simple, but reliable and very cheap charger in a short time. Now it remains to connect it to a computer or network using the usb connector - and you can charge the batteries. How to properly charge them is already clear, the main thing is to follow the indicators. Green color will always signal the charged state of the elements.
You should not often carry out the popular “pumping” of these batteries in the form of several “charge-discharge” cycles. It will be better to monitor the level of their charge: it should not exceed 90%. It is this scheme of actions that will help extend the life of any type of lithium batteries and preserve their capacity as much as possible.
Also, do not allow them to be deeply discharged. - otherwise, it will be very problematic to restore the previous parameters. In order to be sure of buying quality items, you should always pay attention to the time of their release. If they are more than three years old, they can be considered expired.
When you have to constantly deal with this or that portable equipment, you should always know how to charge the battery correctly. If it's an 18650 battery, how do you charge it as productively as possible? Knowing the main indicators of current and voltage, it will not be difficult to carry out the charging process without harming the batteries. And if there is a need and desire, a simple charger can always be made by hand.
19.10.2018
How much, under what conditions and what charge to charge a 18650 lithium-ion type battery directly depends on its operational life. Battery life is negatively affected by deep discharge, overcharging, operation at low temperatures, storage in a discharged state and the use of an inappropriate charger. The rules for recharging Li-ion batteries, first of all, depend on the presence or absence of a protective microcircuit (driver).
How to properly charge a 18650 battery without a protective chip?
In the absence of a protective Li-ion chip, it is important to protect batteries from overcharging and strong discharge - to prevent the voltage from falling below 2.9 V. You need to charge such power sources with special chargers that can inform users about the full recharge of the battery.
After such informing, the battery must be removed from the charger, otherwise overcharging will occur. If necessary, you can remove the battery earlier, until it is fully charged. It is dangerous to charge unprotected batteries with a charger that does not indicate that the battery is fully charged. Batteries without a protective chip will overheat when overcharged and may ignite.
Method of charging Li-ion battery 18650 with protection
Batteries with a protective microcircuit are equipped with a control board that protects the battery from overcharging, strong discharge and short circuit. Recharging takes place as follows:
- The battery is installed in the charger (charger) observing the polarity - plus is connected to plus, minus to minus.
- The charger is connected to a 220 V or 12 V network (for a car model).
- The progress of the charging process is indicated by the charging status indicator. As a rule, a red indicator indicates the progress of the charging process, and a green indicator indicates its completion.
- Do not charge Li-ion cells in chargers not designed for them. Suitable chargers are 5 V constant voltage sources, supply a charge current of 0.5–1 battery capacity, automatically start recharging from 0.05 V and stop charging at 4.2 V.
- A battery brought into a room from a frost must be kept at room temperature for several hours and then charged.
- The battery should be charged to 40-50% before long-term storage.
- Li-ion battery voltage should always be between 2.7-3 to 4.2 V. These values reflect the minimum and maximum charge levels - 0% and 100%. If the voltage goes outside these limits even for a short time, the life of the battery will be significantly reduced.
How to charge a completely dead Li-ion 18650 battery?
If the 18650 lithium-ion battery has been in a discharged state for a long time, the voltage has dropped below the permissible limit, and the protective module has disconnected the jar from the terminals, the charger may refuse to charge such a battery. Perceiving low voltage as an emergency situation, it blocks the charging process. Therefore, a completely dead Li-ion battery must be “pushed” - increase the voltage on it to 3.1–3.2 V.
You can take a charger from a mobile phone that outputs a voltage of 5 V, and a 62 ohm (0.5 W) resistor to limit the charging current. You need to connect them to the battery by attaching the wires to the terminals with neodymium magnets. Strong heating of the resistor indicates the presence of a short circuit inside.
If recharging has not started (the resistor does not heat up), an internal open may have occurred, or the protection board is faulty. You can try to remove the outer polymer shell and connect the created charge to the bank, strictly observing the polarity. If the charge goes, you need to wait for the voltage to rise to 3.1–3.2 V and then use the standard charging.
For those wishing to assemble a charger with their own hands, we suggest that you familiarize yourself with our previous article, which is given.
