One of the most important criteria for correct operation, good efficiency and long service life of a battery is its correct charge. This applies to all batteries, whether they are massive industrial batteries of rather large capacity, or tiny batteries in your tablets or phones.
Most rechargeable batteries have the so-called "memory effect" to some extent. It is expressed in the fact that the batteries "remember" the limits of the exploited capacity.
For this reason, in fact, preparatory battery training is being conducted. Due to the above result, it is not recommended to charge batteries that have not yet sat down to the end.
V in this case rechargeable batteries, among other things, "remember" the limits to which they are given the opportunity to reach.
The result will be a reduction in the physical capacity of the batteries, their rapid discharge, and the fragility of their service.
When purchasing new rechargeable batteries, it is recommended to "train" them. It consists in fully discharging / charging the batteries themselves. Simply put, it is necessary to discharge the batteries, then charge them "all the way". The process is repeated 3-4 times.
As a result of this procedure, the batteries will last significantly longer. With all this, you seem to "overclock" them, increase the potential capacity to the limits.
The fewer times the battery is discharged and the less deep each individual discharge is, the longer its service life will be.
How can you charge the battery?
- The best option is charging with a constant current of 0.1 - 0.2 C for 6-8 hours.
- Fast charge - within 3-5 hours. current is about a third of the nominal.
- Accelerated charging - performed with a current equal to the nominal capacity of the battery itself, heating and destruction of the element is possible.
It is customary to shield that their voltage is 3.7 volts, but one element can have a voltage in the range of 2.5 (discharged) - 4.2 volts, and this is usually the maximum.
On average, their resource is 1000 - 1500 charge-discharge cycles
As a rule, if such a battery is discharged below 2.5 volts or charged more than 4.2 volts, the batteries fail. To protect against this, in most batteries of this type, there is a protection board that turns off the battery bank when the voltages go beyond the normal range.
The charger must be able to charge batteries up to 4.2 volts and automatically disconnect the charge.
A newer type of lithium-ion batteries with a higher energy density and a smaller size (cell thickness from 1mm! With considerable flexibility). Use up to minus 20 degrees. And the complete absence of the "memory effect".
Batteries of this type are explosive and fire hazardous when overcharged, quickly discharged or short-circuited. Therefore, all elements are supplied with a built-in charge and discharge controller board.
The number of working cycles in a row is 900 full charge-discharges. It should be noted that deep discharge can completely destroy the battery. It is recommended to discharge such batteries to no more than 40% of their maximum capacity.
Charging is carried out with a voltage of 4.2 volts per cell, with a current of 1C and the charging process is completed at a current of 0.1-0.2C. Charging time is approximately 2 hours.
Service life, approximately 200-500 charge-discharge cycles. Self-discharge: 100% per year.
To a small extent, the battery has a "memory effect", which means that if the battery has not been used for a long time, a month or two, then it needs to be done full cycle discharge - charge.
Charging with a low current extends the battery life, therefore the most optimal mode of operation will be charging with a current of 0.1 of the nominal battery capacity.
Charge time - 15-16 hours, according to the manufacturer's instructions.
It is better to charge such batteries using a constant or pulsed current with very short pulses of negative value (asymmetric current) - this will help eliminate problems with the "memory effect"
The charge voltage per cell is 1.4 - 1.6 volts, and the voltage of a fully charged cell is 1.4 volts. Discharge up to 0.9 volts, lower is undesirable.
Most are available in the form of AA batteries and small disk accumulators (tablets)
Supply voltage of one element - 1.37 volts
Self-discharge for this type is about 10% per month.
They are subject to the "memory effect" and such batteries are not recommended for use in buffer mode. After a long inactivity of such a battery, it is necessary to perform a charge-discharge cycle with a current of approximately the nominal capacity. Discharge cycle from 1.36 volts to 1 volt, below is not recommended.
The nominal charging current is within 0.1-1 of the nominal cell capacity.
It can be used at temperatures up to minus 50 degrees.
Pb (lead acid) battery
The most common type of battery power.The safest charging method looks like this, first the battery is charged with a constant current, and after obtaining the desired voltage, this voltage is maintained on the battery.
The maximum value of the charging current is 0.2 - 0.3 of the nominal capacity of the battery. The optimal charge current is 10% of the nominal, it is both safe and gentle on the battery.
The maximum charging voltage should not exceed 13.8 volts. Up to 14.5 volts is allowed on a fast charge.
The total time for a full charge should be 5 - 6 hours in early morning.
The minimum charge temperature is not lower than -15 ° C
AGM battery
Unlike lead-acid ones, they contain an absorbed electrolyte, and not liquid as in acidic ones, a kind of glass tissue gaskets between the lead plates are impregnated with electrolyte. And this gives them a number of advantages: resistance to high vibrations, confident operation even at minus 30 C, although the voltage sags a little, sealed design and safer charging.The number of complete charge-discharge cycles is from 500 to 1000, depending on the model brand.
Published on June 23, 2012
The lithium-ion battery is not new, and a lot has been said about how to charge it. I will describe a practical example of a single-cell charge (3.7V) Li-Po battery using power USB- connector. Charging via USB Is the most convenient way for mobile devices and appliances.
But, before describing the charger circuit, consider the batteries themselves. There are simple batteries like these:
And batteries with built-in charge controller. The controller is made in the form of a tiny board soldered to the battery terminals. Please note that these batteries usually have wire contacts.
Indeed, this is logical: to equip the battery with a charge controller. Let it be a little more expensive, but how much less hassle. But what is behind this name: "charge controller"?
It is just a chip to protect the battery against overvoltage, over-discharge and short-circuit. The essence of its action is simple - at exorbitant voltages or currents, the microcircuit turns off the transistor switch, disconnecting the battery from the circuit. Sometimes the output of such a battery is 0V. Do not be alarmed, this does not mean that the battery is dead. It's just that the battery is discharged to the lower limit and the charge controller turned it off. It is enough to charge it.
How to charge such batteries? Answer: as well as Li-Po battery without charge controller. Li-Po a battery with a charge controller is just a battery with additional protection. Which battery is better is up to you. But you must remember that Li-Po the battery is afraid of overcharging and overdischarging. And if the problem with overcharging is solved by the charger, then the likelihood of discharging the battery below the permissible limit forces you to apply Li-Po battery with charge controller.
Thus, we have determined that both options Li-Po batteries - with or without a charge controller - require a dedicated charger. What will happen if Li-Po stupidly plug the battery into the 5V power supply USB? You will be surprised, but the battery will charge! Although the charging process cannot be called normal, and with such a charge, the battery will not last long. And Li-Po the battery with a charge controller will turn off when fully charged (protection will work). Although by this time the battery will have warmed up pretty much, nothing bad may or may not happen. But without a charge controller, the battery can end its life in a bright flash, and burn your computer, or wherever you stick it there, along with your home / office / factory.
There is a cheap "Chinese" way to charge Li-Po battery (but only with a charge controller!) through a current-limiting resistor. And turn on the LED in parallel with the resistor. The LED turns off when fully charged. Those. when the protection is triggered. This method is used in children's Chinese toys, when a moving / flying / floating toy is charged from the batteries of the block. remote control... This method is suitable if your uncle works at a battery factory, and you have these batteries “well, just heaps” (c). We reject it too, although ... no: we reject it all the same. We are not Chinese and we have no uncles at the battery factory! And we love the users of our devices, therefore, charge Li-Po battery we will be correct.
Simple charging scheme for Llipo batteries:
To do this, we take a special microcircuit and turn it on as indicated in. Please note that the microcircuit has two inputs - USB(3.7-6V) and DC(3.7-7V) for connecting the power supply Direct current... Those. at least straightened.
I made a small test shawl for. The LED glows while the charge is in progress and goes out when the battery charging is complete. If the battery is not connected, the LED is off.
As a result, we have a miniature Charger for Li-Po batteries. Such a circuit can be built into the board of your device and charge it from USB... In combination with Li-Po battery with a charge controller, we get a device with full protection Li-Po battery and the correct charger. Long years of service to you Li-Po!
Today one of the most popular battery formats for various electronic devices is 18650. It requires proper handling during operation. The durability and functionality of this power source depends on this.
How to charge an 18650 battery should be considered in detail. The advice of experts will help you figure it out.
general characteristics
Today many standard sizes are used and one of the most demanded is the 18650 battery. It has a cylindrical shape. Outwardly, such a battery resembles finger batteries. Only the presented view is slightly larger in size than the usual devices.
During operation, the question of how to charge the 18650 battery necessarily arises. This is a simple procedure. However, you need to take it responsibly. The durability of the battery depends on the correct charging.
Batteries of the presented type are used today to power laptops, as well as electronic cigarettes. This made the presented standard size popular. Also, such batteries are installed in flashlights and laser pointers. Most often, the presented devices are of the lithium-ion type. This type of battery has proven to be effective and easy to use.
Peculiarities
Considering how to charge an 18650 battery for a flashlight, electronic cigarette and other devices, it is necessary to describe the principle of its operation. The presented standard size is produced in the category lithium ion batteries... It has small 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 generate electric current to power equipment. With a low or high charge, more ions are formed on one of the electrodes. They grow on the material, 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. Special types of chargers are used depending on the battery rating.
Battery protection
Today, the presented types of batteries are available complete with a special controller or contain manganese. Previously, batteries were produced without protection. How to charge the 18650 battery correctly in this case, you had to know for your own safety.
The fact is that the device, which lacked special protection, could overheat severely if it was charged incorrectly or too long. In this case, a short circuit and even a fire could occur, or Today the use of such structures has sunk into oblivion.
All lithium-ion batteries are designed to be protected against such negative phenomena. Most often, a special controller is used. It monitors the battery capacity level. It simply disconnects the battery if necessary. Some types of structures contain manganese. It significantly affects chemical reactions inside. Therefore, these batteries do not need a controller.
Charging features
Many buyers are wondering how to charge a 18650 Li-Ion (3.7V) battery. You need to familiarize yourself with the features of such a process. It's pretty simple. Modern manufacturers make special devices that control battery charging.
Lithium-ion batteries have virtually no memory effect. This provides a number of guidelines for charging and operating batteries. The memory effect is the gradual decrease in the capacity of the battery when it is not fully discharged. This property was characteristic of nickel-cadmium batteries. They had to be completely discharged.
On the contrary, they do not tolerate deep relaxation. They need to be charged up to 80% and discharged to 14-20%. In such conditions, the device will serve as long and productive as possible. The presence of special boards in the design simplifies this process. When the capacity level drops to a critical value (most often to 2.4 V), the device disconnects the battery from the consumer.
Charging
Many buyers of various electrical engineering are interested in how to charge a 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 ends at a maximum level of 4.2 V. Above this value, the battery of the presented type cannot be charged.
You can charge 18650 batteries with 0.5-1A current. The larger it is, the faster the process goes. However, a smoother current is preferred. It is best not to speed up the charging process unless the battery needs to be used urgently.
The procedure takes no more than 3 hours. The device will then disconnect the battery. This prevents overheating and failure. There are devices on sale for charging that cannot control the course of this process. In this case, the user must monitor its implementation himself. Experts recommend purchasing devices that control the process themselves. This is a safe method.
Parameters
Batteries with different capacity indicators are on sale. This affects the operating time and the charging process. Batteries of 1100-2600 mAh have a small capacity. The most popular in this category are UltraFire products. This manufacturer makes quality flashlights. Therefore, consumers have a reasonable question about how to charge the 18650 UltraFire battery.
In this case, it should be noted that devices with a capacity of up to 2600 mAh must be charged with a current of 1.3-2.6 A. This process is carried out in several stages. At the beginning of charging, a current is supplied to the battery, which is 0.2-1 of the value of the battery capacity. At this point, the voltage is maintained at about 4.1 V. This stage lasts about an hour.
During the second stage, the voltage is kept at a constant level. For some manufacturers of chargers, this procedure can be carried out using alternating current. It should also be noted that if there is a graphite electrode in the battery design, it cannot be charged with a current greater than 4.1 V.
Varieties of chargers
There is a simple method of how to charge the battery. To do this, you will need to buy a certain type of device. On sale presented big choice charging equipment for batteries of this type. The simplest and most inexpensive device is for one battery. The current level in it can reach 1 A.
Devices in which several batteries can be placed at once are very popular. Most often, such designs are equipped with an indicator. Some models can be used with other types of lithium-ion batteries. Their seats are designed accordingly. Such devices are distinguished by an acceptable cost and high functionality.
Also on sale are universal chargers. They can charge not only lithium-ion type batteries, but other types as well. Such units must be correctly configured before carrying out the procedure.
Homemade device
Some users have a question about how to charge an 18650 battery emergency situation when a special device is not at hand. In this case, you can do it yourself. An old phone charger (for example, Nokia) will do.
It is necessary to remove the sheath of the wire and disconnect the minus (black) and plus (red) wires. With the help of plasticine, you can attach the bare contacts to the battery. The correct polarity must be observed. Then the device is connected to the network.
This charge can take about an hour. This will be enough for the battery to ensure the correct operation of the equipment.
Experts recommend taking a responsible attitude to the charging process and its durability depends on it. It is not worth discharging the battery completely and charging it to 100%. Better to limit the charging process to 90%. However, periodically (once every three months), you can completely discharge and fully charge the battery. This is required to calibrate the controller.
The battery can be stored for a long time. To do this, you need to charge it by 50%. She can stay in this state for about a month. At the same time, the room should not be too hot or too cold. The ideal conditions are considered to be keeping the temperature at the level of 15 ºС.
By considering how to charge an 18650 battery, you can properly maintain and operate the battery. In this case, the period of its use will be much longer.
The first company to launch in mass production The high-capacity rechargeable lithium-ion battery is now Sony, and the battery life is significantly longer than its nickel-cadmium counterpart.
Unfortunately, the first models had a significant drawback, which manifested itself in the fact that at a high discharge current, the lithium anode ignited.
It took about 20 years to fix this problem, the solution was a controller that does not allow the formation of pure lithium at the anode of a lithium-ion type battery.
Modern models are reliable and safe, they gradually replaced nickel-metal hydride and nickel-cadmium from the market. rechargeable batteries in portable devices, they are installed as a power source for a laptop, a camera, mobile phone etc.
The only niche in which lithium-ion batteries are inferior to nickel-cadmium batteries are devices that require a high discharge current, for example, for screwdrivers. This type of battery is called an industrial battery.
Separately, it is worth mentioning the Li-Pol cells. The only difference from a lithium polymer battery is that baseline a different electrolyte is used, while the principle of operation, features and characteristics of these types are almost identical.
Peculiarities
Any type of power supply has its own advantages and, accordingly, disadvantages, lithium ion batteries only confirm this axiom. Let's consider in detail their characteristic features.
The advantages undoubtedly include:
- low self-discharge parameters;
- if you take a single cell of a lithium-ion battery, the dimensions of which are equal to batteries of another type, then its charge will be greater (3.7V, as opposed to 1.2V). Thanks to this, it became possible to significantly simplify and lighten the battery;
- there is no such parameter as power memory, that is, the battery does not need to be regularly discharged to restore power (capacity), which simplifies operation.
Talking about the advantages of this battery cell, certain disadvantages cannot be ignored, which include:
- built-in "fuse", that is, a protection board whose task is to limit the supply voltage during charging and prevent a complete discharge of the battery; in addition, the maximum current is smoothed out, and the temperature is also controlled. Because of this, the price of lithium-ion batteries is higher than that of analogues;
- Although remanufactured, lithium-ion batteries are subject to "aging" even if stored properly. How to slow down this process, will be discussed below, where the operation and its features will be considered.
Video: review, opening a lithium-ion battery from a mobile phone
Form factor
Lithium-ion batteries are available in two form factors - cylindrical and tablet.
Many devices use several connected lithium-ion batteries, for example, in order to reach a voltage of 12V or increase the discharge current, this must be taken into account if you want to buy such a device (as a rule, the connection type is indicated on the case).
How to charge correctly
There are guidelines that can significantly extend the life of lithium-ion batteries.
Rule one: you must not allow full discharge, thanks to this, you can increase the number of cycles during which charging and discharging occurs. By charging the battery by 20%, you can significantly extend its service life, at least twice. As an example, we give a table of the dependence of the charging cycles, depending on the depth of discharge of the battery.
Rule two: once every three months, it is required to perform a full cycle (that is, to completely discharge and charge), due to which the aging process of the batteries is significantly slowed down.
Rule three: you cannot store a lithium-ion type battery completely discharged, it is desirable that the battery is charged at 30-50%, otherwise it is not possible to restore its capacity.
Rule four: to charge the battery, use the original charger that came with the manufacturer, this is required by the difference in the performance of the battery protection circuit. That is, for example, HTC, En-El, Sanyo, IRC, ICR, Lir, Mah, Pocket, ID-Security batteries, etc. it is not advisable to charge the device for Samsung batteries.
Rule five: do not overheat the battery, you can operate the lithium-ion device at an ambient temperature of -40 to 50 ° C. If the temperature regime is violated, it is not possible to restore the battery or repair it, only its replacement is required.
Separately, it should be emphasized that rechargeable batteries of well-known brands are significantly superior in performance to analogues of unknown manufacturers. You can rest assured that the batteries are DMW-BCG, VPG-BPS, SAFT, as well as original models, for example, BL-5C, BP-4L (Nokia), D-Li8, NB-10L (Canon), NP-BG1 (Sony ) or LP243454-PCB-LD will definitely be better than their Chinese counterparts.
Homemade charger
If you wish, you can do it yourself a device that will serve to charge lithium-ion batteries, its diagram is shown below.
Designations in the figure:
- R1 - 22 Ohm;
- R2 - 5.1kOhm;
- R3 - 2kOhm;
- R4 -11 Ohm;
- R5 - 1kOhm;
- RV1 - 22kOhm;
- R7 - 1kOhm;
- U1 - LM317T stabilizer (be sure to install on a radiator with a large dissipation area);
- U2 - TL431 (voltage regulator);
- D1, D2 - LEDs, you can use smd type, the first, signaling the start of the charging process, it is desirable to select red, the second - green;
- transistor Q1 - BC557;
- capacitors C1, C2 - 100n.
The input voltage to the charging circuit for lithium-ion batteries must be from 9 to 20V; for this purpose, you can redo the switching power supply. The power of the resistors must be selected as follows:
- R1 - at least 2W;
- R5 - 1W
- the rest are not less than 0.125W.
as a variable resistor RV1, it is advisable to take CG5-2 or its imported analogue 3296W. This type allows you to more accurately set the output voltage, which should be about 4.2V.
The principle by which the charging circuit works is as follows:
When the battery is turned on, the current value depends on the resistor R5 (in our case, it will be at the level of 100mA), the charging voltage is in the range from 4.15 to 4.2V, the diode D1 will signal the start of the process. When the battery approaches the charging threshold, the load current will decrease, which will turn off LED D1 and turn on D2.
Note that when the voltage drops by about 0.05-0.1V, the battery life can be significantly increased, since it will not be fully charged.
The contacts for the charging unit, through which the battery will be connected, can be taken from a broken device, do not forget to clean them before that.
Please note that if the setting is incorrect, for example, overvoltage or charging current, the battery can be damaged.
The production of a charger is much cheaper than the price of a lithium-ion battery, be it the city of Moscow or St.
Ultra-compact charger for both 1S (3.7V / 4.2V) and 2S (7.4 / 8.4V) lithium batteries - primarily for all kinds of photo and video equipment and various flashlights that do not have their own built-in "carcass" charging (as well as for charging additional batteries). The range of input operating voltages is 5-18V (it is required that the voltage at the input is at least 1V higher than the voltage on the battery being charged).
Charge current:
- for 3.7V - 0.75A
- for 7.4V - 1A
These charge currents are optimal and universal (and most importantly, they are safe !!!) for the vast majority of batteries of any photo and video cameras.
To estimate the dimensions, there is a ruble coin in the photo :)
Waterproof design. Protection against short circuit and polarity reversal (it really works - I checked it myself! :)
For "crawling" to the contacts of the battery, adjustable clamping contacts from the "ketai frog" are used. It is possible (with difficult "crawling" due to the battery design) to swap the plus and minus contacts of the "frog".
And, of course, there are always options to connect to the battery contacts "alternatively", for example, by fixing the conductors with an elastic band or electrical tape :)
For batteries with "very cleverly made" contacts (and these are, as a rule, Sony batteries), a connector with wiring is additionally attached in order to slightly "upgrade" the original charger - to solder this connector to the output contacts of the original charging.
Switching between 3.7V and 7.4V is done by opening or closing the wire (see photo). The state is closed - 7.4V, open - 3.7V (this information is also "drawn" on the board, for the forgetful :)
The output connector from the board (which is to the battery) is made by me compatible with the entire family of universal chargers such as iMax (male connector 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 marching ones - for lightness and compactness, just take this scarf instead of iMax, a little larger than a ruble coin :)
Important note:
This charger board has one feature (this is more likely not a "bug", but a "feature" - but you still need to take into account) - it has a VERY slow final part of charging (CV - Constant Voltage). Roughly speaking, up to about 98% of the battery capacity charging is in progress quite smartly (within the indicated currents), but the final “finishing off” is goingoooooo! Those. from the moment when the battery is in fact already charged, and until the LED indicator lights up, signaling the end of the charge, it can take a very long time!
And in some cases (mainly, this applies to 7.4V batteries from photo-video), you may not even wait for the LED to light up - as, for example, in the battery of my Pentax DSLR ... The fact is that its battery contains a balancing board that “bleeds »Voltage up to 8.3V - while the charging board is waiting for 8.4V to be established :) And in the end, it never waits for it ... :)
How to deal with this? Yes, very easy!
Firstly, you can just estimate the charging time (and we know the charging current, the battery capacity is also written on it). For example, we charge a battery with a voltage of 7.4V (designations 7.2V or 8.4V are all the same :) and with a capacity of 1600mAh. Accordingly, with a charging current of about 1A, the battery can be considered charged in about an hour and a half.
Secondly, you can simply touch the throttle on the charger board with your finger (this is such a large square-round part on the board, the largest of all the details :) If it is warm to the touch, it means that active charging is still going on. But if its temperature does not differ much from the overall temperature of the entire board (you obviously cannot feel it with your finger), then active charging is over, and you can safely disconnect the battery.
The main thing to remember here is a simple truth: a small undercharge for lithium-ion batteries is not only not harmful in any way, but everything is exactly the opposite, it is very useful for increasing their service life !!! So don't be afraid in the least lithium batteries undercharge, only beware of overcharging (fortunately, this charging board will not allow you to do this :) 
