Lithium battery (Li-Io, Li-Po) are currently rechargeable sources. electrical Energy. Lithium battery has rated voltage 3.7 volts, it is it indicated on the housing. However, a charged 100% battery has a voltage of 4.2 V, and the discharged "in zero" - 2.5 B, there is no point in discharge the battery below 3 V, first, it will deteriorate from this, secondly, in the interval from 3 to 2.5 In the battery gives just a couple of percent of energy. Thus, the working voltage range is accepted 3 - 4.2 volts. My selection of tips for operation and storage lithium batteries You can see here in this video.
There are two options for connecting batteries, consistent and parallel.
For sequential connection Suggested voltage on all batteries, when the load is connected from each battery, a current is currently equal to a total current in the chain, in general the load resistance sets the discharge current. This you must remember from school. Now the most interesting, container. The assembly capacity with such a connection for a good equal to the battery capacity with the smallest container. Imagine that all batteries are charged 100%. See, the discharge current here is the same everywhere, and the first battery with the smallest capacity is first, it is at least logical. And as soon as it is discharged, it will be impossible to load this assembly. Yes, the remaining batteries are still charged. But if we continue to remove the current, then our weak battery Start reproduced, and fails. That is, it is correct to assume that the tank of the connected assembly is equal to the tank of the very tight, or the most discharged battery. From here we conclude: it is necessary to collect a sequential battery at first of the same batteries on the capacity, and secondly, before assembly, they should all be charged the same, simply speaking by 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 turns off the entire battery from the load, this will be discussed below. Now it concerns charging such a battery. It is necessary to charge it with a voltage equal to the sum of maximum voltages on all batteries. For lithium it is 4.2 volts. That is, the battery of three is charged with a voltage of 12.6 V. See what happens if the batteries are not the same. The battery with the smallest capacity will be charged faster. But the rest are still not charged. And our poor battery will be fried and recharge until the rest are charged. Referee, I remind you, lithium also does not like very much and flies. To avoid this, remember the previous conclusion.
Let us turn to the parallel connection. The capacity of such a battery is equal to the sum of the containers of all batteries in it incoming. The discharge current for each cell is equal to the total current of the load shared by the number of cells. That is, the more Akumov in such an assembly, the greater the current it can give. But with a voltage there is an interesting thing. If we collect batteries that have different voltages, that is, roughly speaking charged to a different percentage, then after the connection they will begin to exchange energy until the voltage on all cells becomes the same. We conclude: Before assembling akuma, again, they must be charged the same, otherwise there will be big currents when the connection will be departed, and the discharged Akum will be spoiled, and most likely can even light up. In the process of discharge, the batteries also exchange energy, that is, if one of the cans has a lower capacity, the rest will not be able to discharge them faster themselves, that is, in a parallel assembly, you can use batteries with a different container. The only exception is to work at high currents. On the different batteries Under the load, the voltage is different in different ways, and the current will start running between the "strong" and "weak" akum, and we do not need it at all. And the same applies to charging. You can absolutely calmly charge different batteries in parallels, that is, the balancing is not needed, the assembly will balance itself.
In both cases considered, the charging current and discharge current must be observed. Charging current for Li-IO should not exceed half the battery capacity in amperes (1000 Mah battery - charge 0.5 A, 2 AH battery, charge 1 A). The maximum discharge current is usually specified in the datashet (TTX) battery. For example: laptop 18650 and batteries from smartphones can not be shipped with current exceeding 2 battery capacity in amperes (example: AKUM at 2500 mAh, it means that the maximum you need to take 2.5 * 2 \u003d 5 amps). But there are high-strength batteries, where the discharge current is explicitly specified in the characteristics.
Features of charging batteries by Chinese modules
Standard purchased charging and protective module for 20 rubles for lithium battery ( link to Aliexpress.)
(Positioned by the Seller as a module for one bank 18650) maybe it will charge any lithium battery, regardless of the form, size and container Prior to the correct voltage of 4.2 volts (voltage of a fully charged battery, under the string). Even if it is a huge lithium package for 8000mAh (of course it is about one cell by 3.6-3.7V). The module gives a charging current of 1 ampThis means that they can be charged without fears to charge any battery with a capacity of 2000mAh and higher (2Ah, which means the charging current - half the tank, 1a) and, accordingly, charging time in the clock will be equal to the battery capacity in amps (actually a little more, one and a half or two hour for every 1000mAh). By the way the battery can be connected to the load during the charge.
Important! If you want to charge a smaller capacity battery (for example, one old jar at a 900mAh or a tiny lithium bag at 230mAh), then the charging current 1a is a lot, it should be reduced. This is done by replacing the R3 resistor on the module according to the applied table. The resistor is optional to SMD, the most common one will suit. I remind you that the charging current should be half of the battery capacity (or less, not scary).
But if the seller says that this module for one bank is 18650, can they charge two banks? Or three? What if you need to assemble the capacious PowerBank from several batteries?
CAN! All lithium batteries can be connected in parallel (all the advantages to the advantages, all cons by cons) regardless of the tank. Speeded parallel batteries retain the operating voltage of 4.2V and their container is developing. Even if you take one jar at 3400mAh and the second to 900 - it turns out 4300. Batteries will work as one whole and discharge will be proportional to its container.
The voltage in the parallel assembly is always the same on all batteries! And no battery can physically be discharged in the assembly before others, the principle of reporting vessels works here. Those who claim the opposite and say that the batteries with a smaller capacity are discharged faster and die - confused with a consistent assembly, spit them into the face. 
Important! Before connecting to each other, all batteries must have about the same voltage, so that equation currents are not flowed between them, they can be very large. Therefore, it is best before assembling simply charge each battery separately. Of course, the time for charging the entire assembly will increase, since you use the same module on 1a. But you can spararal the two modules, getting a charging current to 2a (if your charger Maybe so much). To do this, it is necessary to connect with jumpers all similar terminals of the modules (except Out- and B +, they are duplicated on cards by other fives, and so will be connected). Or you can buy a module ( link to Aliexpress.), where chips are already in parallel. This module is able to charge a current of 3 amps.
Sorry for completely obvious things, but people are still confused, so you have to discuss the difference between the parallel and consistent compound.
Parallel Compound (all the advantages to the pros, all cons by cons) retains 4.2 volt battery voltage, but increases the container, folding all the containers together. All Power Banks use a parallel connection of several batteries. Such an assembly can still be charged from a USB and the voltage increases up to the output 5V.
Consistent The compound (each plus to minus the subsequent battery) gives a multiple increase in the voltage of one charged bank 4.2V (2S - 8.4V, 3S - 12,6V and so on), but the container remains the same. If three batteries are used for 2000mAh, the assembly capacity is 2000mAh.
Important! It is believed that for consistent assembly, it is necessary to use only the batteries of the same container. In fact, it is not. You can use different, but then the battery capacity will be determined by the smallest tank in the assembly. Fold 3000 + 3000 + 800 - get an assembly to 800mAh. Then the specialists begin to sway that the less capacious battery will be quickly discharged and die. And it does not matter! The main and truly sacred rule - for consistent assembly always and necessarily you need to use the BMS protection fee for the desired number of cans. It will determine the voltage on each cell and turn off the entire assembly if some kind of discharge is first. In the case of a bank for 800, it will also be discharged, bms will turn off the load from the battery, the discharge will stop and the residual charge of 2200mAh on the rest of the banks will not be valid - it is necessary to charge.
The BMS fee in contrast to the single charging module is not a sequential assembly charger. For charging need configured source of the desired voltage and current. About this gamever shot a video, so do not waste time, look at it, there is much thoroughly about it.
Is it possible to charge a consistent assembly by connecting multiple single charging modules?
In fact, with some assumptions - it is possible. For some homemakes, a scheme has proven to use single modules connected also in series, but for each module, a separate power supply is needed. If you charge 3s - take three telephone charging and connect each one to one module. When using one source - nutrition short circuit, nothing works. Such a system also works and how the assembly protection (but the moduli is able to give no more than 3 amps) or simply charge the assembly shipping, connecting the module to each battery to a complete charge.
Accumulator charge indicator 
Also a pressing problem - at least approximately know how many percent of the charge remains on the battery so that it does not discharge in the most responsible moment.
For parallel assemblies by 4.2 volts, the most obvious solution will immediately purchase a ready-made PowerBank fee, which already has a display that displays the charge percentage. These percentages are not super-accurate, but still help. The issue price is approximately 150-200rub, all are presented on the website of the Gaiver. Even if you are collecting not Powerbank and something else, this fee is quite cheap and small to place it in the homemade. Plus it already has a battery protection and protection function.
There are ready-made miniature indicators on one or more cans, 90-100r 
Well, the cheapest and folk method is to use the MT3608 increasing converter (30 rubles), configured by 5-5.1V. Actually, if you make Powerbank on any 5 volt transmitter, then you don't even need to buy anything. The revision is to install a red or green LED (other colors will operate on another output voltage, from 6V and above) through a current-limiting resistor 200-500 between the output plus terminal (it will be plus) and the input plus (for the LED it will turn out to be minus). You are not mistaken, between two pluses! The fact is that during the operation of the converter between the advantages, the difference of voltage is created, +4.2 and + 5V, the voltage is 0.8V. When the battery discharge, its voltage will fall, and the output from the converter is always stable, then the difference will increase. And at a voltage on a bank, 3.2-3,26VI, the difference will reach the necessary value to light the LED - it begins to show that it is time to charge.
How to measure the capacity of batteries?
We are already accustomed to the belief that Iamaks B6 needs for measurement, and it costs money and for most radio amateurs is excessive. But there is a way to measure the capacity of 1-2-3bachal batteries with sufficient accuracy and cheaply - a simple USB tester.
Today, one of the most popular battery formats for various electronic devices is 18650. It requires when operating proper handling. The durability and functionality of this power supply depends on this.
How to charge the battery 18650, you should consider in detail. This will help to understand the advice of specialists.
general characteristics
Today, many sizes are used and one of the most popular is a battery of type 18650. It has a cylindrical shape. Externally, such a battery resembles finger batteries. Only the presented view is slightly more in size than the usual devices.
In the course of operation, necessarily the question of how to charge the battery 18650. This is a simple procedure. However, refer to it with full responsibility. The durability of the use of the battery depends on the correctness of the charging.
The batteries of the presented type are used today to power laptops, as well as electronic cigarettes. This made presented sizes popular. Also, such batteries are installed in flashlights and laser pointers. Most often, the devices presented are produced by lithium-ion type. This type of batteries proved its effectiveness and simplicity during operation.
Features
Considering how to charge the 18650 battery for a flashlight, electronic cigarette and other devices, it is necessary to describe the principle of its operation. Presented standard samples are available in category lithium-ion batteries. It has minor dimensions. The height is only 65 mm, and the diameter is 18 mm.
Inside the device there are metal electrodes, between which lithium ions circulate. This allows you to produce an electric current to feed the technique. With a low or high charge on one of the electrodes, more ions are formed. They grow on the material by changing its volume and characteristics.
In order for the battery to work for a long time and fully, it is necessary to prevent the appearance of a deep or too high charge. Otherwise, the device will quickly fail. Depending on the nominal battery rates, special types of charging devices are used.
Battery protection
Today, the presented varieties of batteries are available complied with a special controller or have a manganese. Previously, there were batteries without protection. How to charge the battery 18650 correctly in this case, it was necessary to know for your own security.
The fact is that the device in which there was no special protection could be very overheated with an incorrect or too long charging. In this case, a short circuit could occur and even ignition or today the use of such structures has sunk in the fly.
All lithium-ion type batteries have protection against such negative phenomena in their design. The special controller is most often applied. It monitors the battery capacity. If necessary, it simply turns off the battery. In some types of structures, a manganese is included. He significantly affects chemical reactions Inside. Therefore, such batteries controller is not needed.
Features of charging
Many buyers are interested in how to charge the 18650 Li-ion battery (3.7V). You need to familiarize yourself with the features of this process. He is quite simple. Modern manufacturers make special devices that control the battery charging.
Lithium-ion batteries have practically no memory effect. This provides a number of rules when charging and operating batteries. The effect of memory is the gradual decrease in the battery capacity with an incomplete discharge. This property was characteristic of nickel-cadmium batteries. They needed to discharge completely.
On the contrary, do not tolerate deep discharge. They need to be charged to 80% and discharge up to 14-20%. In such conditions, the device will serve as long as possible and productive. The presence of special boards in the design allows you to simplify this process. When the capacity level drops to a critical value (most often up to 2.4 V), the device turns off the battery from the consumer.
Holding charging
Many buyers of various electrical engineering are interested in how to charge the 18650 Li-Ion battery (3.7V, 6800mAh). This process is carried out using a special device. It starts charging at a voltage of 0.05 V, and finishes at the maximum level 4.2 V. Above this value, the battery is not necessary.
You can charge the batteries of 18650 current 0.5-1a. What he is more, the faster the process passes. However, more smooth current is preferable. It is better not to speed up the charging process if the battery does not need to be used urgently.
The procedure takes no more than 3 hours. After that, the device will turn off the battery. This prevents its overheating and failure. Available for charging devices that cannot control the flow of this process are presented. In this case, the user must follow its execution. Experts recommend purchasing devices that themselves manage the process. This is a secure method.
Parameters
Batteries with different capacity indicators are available. This affects the duration of the work and the process of charging. Low capacity has a battery 1100-2600 mAh. The most popular in this category are Ultrafire products. This manufacturer manufactures high-quality lights. Therefore, consumers have reasonably the question arises on how to charge the battery 18650 Ultrafire.
In this case, it should be noted that the devices with a capacity of up to 2600 mAh need to be charged with a current of 1.3-2.6 A. This process is carried out in several stages. At the beginning of charging, the battery enters the current, which is 0.2-1 from the size of the battery capacity. At this point, the voltage is maintained at about 4.1 B. This stage lasts about an hour.
During the second stage, the voltage is held at a constant level. For some manufacturers of charging, this procedure can be carried out using AC. It should also be taken into account that in the presence of a graphite electrode in the battery design, it cannot be charged with a current more than 4.1 V.
Varieties of chargers
There is a simple technique, how to charge the battery for this you need to buy a specific type of device. On sale presented big choice Charger for batteries of this type. The simplest and inexpensive is the device for one battery. The current level in it can reach 1 A.
Instruments in which several batteries can be placed immediately. Most often, such designs are equipped with an indicator. Some models can also be used for other varieties of lithium-ion type batteries. Their planting sockets have the appropriate design. Such devices differ acceptable cost and high functionality.
Also available universal chargers are presented. They can charge batteries not only lithium-ion type, but also other varieties. Such aggregates need to be properly configured before conducting the procedure.
Homemade instrument
Some users have a question about how to charge the 18650 battery in emergency situationWhen there is no special device at hand. In this case, it can be done independently. An old charger is suitable on the phone (for example, "Nokia").
It is necessary to remove the shell of the wire and disconnect the wires minus (black) and plus (red). With the help of plasticine, you can attach the bare contacts to the battery. It is necessary to observe the appropriate polarity. Next, the device includes network.
Such charging can last about an hour. This will be enough enough to ensure that the battery can provide the right work of the technique.
Specialists recommend responsibly referring to the charging process and its durability depends on it. Discharge the battery completely and charge it up to 100%. It is better to limit the charging process to a level of 90%. However, periodically (once every three months) can be fully discharged and complete battery charging. This is necessary to calibrate the controller.
You can store a battery long enough. For this you need to charge by 50%. In such a state, it can be about a month. At the same time, it should not be too hot or too cold. The ideal conditions are considered to hold temperatures at 15 ºС.
Having considered how to charge the battery 18650, you can maintain and operate the battery correctly. In this case, its use will be significantly longer.
Publikovano 23.06.2012
The battery is a lithium-ion - the thing is not new and many of the ways to charge it. I will describe a practical example of a charm of a single-bounte (3.7V) Li-Po. battery using food USBconnector. Charging USB - This is the most convenient way for mobile devices and appliances.
But, before describing the charger scheme, consider the batteries themselves. There are simple batteries, such as such:
And batteries with a built-in charge controller. A controller is performed as a tiny board soldered to the battery conclusions. Please note that such batteries usually have contacts in the form of wires.
Indeed - this is logical: to supply the battery controller charge. Let slightly more expensive, but how much less hassle. But what lies under this title: "Charge controller"?
This is just a battery protection chip from overvoltage, excessive discharge and short circuit. The essence of its actions is simple - with extended voltages or current, the chip turns off the transistor key, disconnecting the battery from the chain. Sometimes there is a voltage of 0V at the output of such a battery. Do not be scared, it does not mean that the battery "died." Just the battery was discharged to the lower limit and the charge controller turned off it. It is enough to charge it.
How to charge such batteries? Answer: just like Li-Po. Battery without charge controller. Li-Po. Battery with charge controller is just a battery with additional protection. What battery is better - choose to you. But you must remember that Li-Po. The battery is afraid of excessive charge and excessive discharge. And if the problem with an excessive charge is solved by the charger, the probability of discharge the battery below the permissible limit is forced to apply Li-Po. Battery with charge controller.
Thus, we decided that both options Li-Po. Accumulators - and with charge controller and without it - require a special charger. What will happen if Li-Po. Battery stupid to stick to 5V power USB? You will be surprised, but the battery charges! Although the process of charging is not called normal, and with such charging the battery will not live for a long time. Moreover Li-Po. Battery with charge controller with full charge will turn off (protection will work). Although by this time the battery is pretty pretty, nothing terrible, may not happen. But without charge controller, the battery can end up life in a bright flash, and burn your computer, or where you get it there, along with the house / office / factory.
There is a cheap "Chinese" way to charge Li-Po. Battery (but only with charge controller!) Through a current-limiting resistor. And parallel to the resistor include the LED. The LED goes out with full charge. Those. When protecting protection. This method is used in children's Chinese toys, when moving / flying / floating toy is charged from block batteries remote control. This method is suitable if your uncle works on the battery factory, and you have these batteries "well, they just went out" (c). We also reject it, although ... no: still reject. We are not Chinese and uncle on the rechargeable factory we have no! And we love the users of our devices, so, charge Li-Po. Battery We will be correct.
Simple battery llipo charging scheme:
For this we take a special chip and turn it on as indicated in. Please note that the microcircuit has two inputs - USB (3.7-6V) and DC (3.7-7B) for connecting the power supply Direct current. Those. At least straightened.
I made a small test scarf for. The LED glows while the charge goes and goes well when charging the battery is completed. If the battery is not connected, the LED does not burn.
As a result, we have a miniature charger for Li-Po. batteries. Such a scheme can be built on the fee of your device and charge it from USB. In combination with Li-Po. Battery with charge controller Get a complete protection device Li-Po. Battery and correct charger. Long years of service Li-Po.!
Over-compact charging for lithium batteries as 1s (3.7V / 4.2B) and 2s (7.4 / 8.4B) - first of all, for all sorts of photo-video techniques and different lanterns that do not have their own built-in "carcass" Charging (as well as for charging additional batteries). The range of input voltages 5-18B (required so that at the input voltage is at least 1B higher than the voltage on the charging battery).
Charge current:
- for 3.7V - 0.75a
- for 7.4B - 1A
These charge currents are optimally universal (and most importantly, safe !!!) for the overwhelming majority of batteries of any photo-video cameras.
To assess the dimensions in the photo is a ruble coin :)
Waterproof performance. Protection against short circuit and crooked polarity (really works - I checked it yourself! :)
For "subjects" to battery contacts, customizable clamping contacts from the "Ketai frog" are used. There is an opportunity (with difficulty "subject" due to the battery design), change places plus and minus the contacts "Frog".
Well, naturally, there are always options to connect to the accumulator contacts "Alternatively", for example, by fixing the conductors using an elastic band or isol :)
For batteries with "very hit-up" contacts (and this, as a rule, Sony batteries) additionally attached the wiring detachable in order to slightly "upgrade" the original charger - to fall this connector to the output contacts of the original charging.
Switching between 3.7V and 7.4B is made by opening or closing the wiring (see photo). The condition is closed - 7.4V, open - 3.7V (this information is also "drawn" on the board, for forgetful :)
The output connector from the board (which is to the battery) is made by me compatible with the whole family of universal type charges imax (Dad connector of type Deans. , he is T-plug. ) - i.e. can be used at home (and in the car) imax (With the same "frog" and other contacts), and in purely hiking - for lightness and compactness, just take this scarf instead of Imax, the size of a little more ruble coin :)
Important note:
This charge charge has one feature (this is rather a "bug", but "Fich" - but you need to take into account) - she has a very slow the final part of the charging (CV - Constant Voltage). Roughly speaking, about 98% battery capacity charging goes Quickly (within the framework of the indicated currents), but the final "attracting" - sooooooo slowly! Those. From the moment when the battery is already charged, and before the lighting of the LED indicator, signaling about the end of the charge, can take a very long time!
And in some cases (basically, it concerns the batteries of 7.4V from the photo-video), it is possible and not to wait for the lighting of the LED - as, for example, in the battery of my pentakovskaya mirror ... The fact is that in its battery there is a balancing board, "Balancing "Voltage up to 8.3V - while charging fee is waiting for an estimate of 8.4V :) And in the end, it does not wait for it ... :)
How to deal with it? Yes very easy!
First, you can simply estimate the charging time (and the charging current is known to us, the battery capacity is also written on it). For example, I charge the battery with a voltage of 7.4B (7.2V or 8.4B designations - it's all the same :) and a capacity of 1600mAh. Accordingly, with a charge current about 1a, the battery can be considered after an hour and a half.
Secondly, you can simply touch the throtsel on the charge charge (this is such a large square-round item on the board, the largest of all the details :) if it is warm to the touch, then active charging continues. But if its temperature differs little from the total temperature of the entire board (it is clearly not felt by the finger), it means that the active charging is over, and you can safely disconnect the battery.
Here the main thing is to remember the simple truth: a small underwear for lithium-ion batteries Not only is not harmful, but everything is exactly the opposite, it is very useful to increase their service life !!! So do not be afraid of lithium batteries for no fear, we wonder only reloading (fortunately, this charging board does not allow this :) 
