Many probably have a problem with charging a Li-Ion battery without a controller, I had this situation. I got a dead laptop, in the battery 4 banks of SANYO UR18650A turned out to be alive.
I decided to replace the LED flashlight, instead of three AAA batteries. The question arose about charging them.
Having rummaged in the Internet I found a bunch of sketches, but with details in our city it’s a little tight.
I tried to charge from the cellular charge, the problem is charge control, you need to constantly monitor the heating, it starts to heat up a little, you need to disconnect the charge from the battery, otherwise the battery in the best case, or you can make a fire.
I decided to do it myself. I bought a bed under the battery in the store. I bought a charge at a flea market. For convenience, tracking the end of the charge, it is advisable to find a two-color LED that signals the end of the charge. It switches from red to green when charging is complete.
But you can and the usual. Charging can be replaced with a USB cable, and charging from a computer or charging with a USB output.
My charging is only for batteries without a controller. I took the controller from the old cell phone battery. It ensures that the battery is not recharged above 4.2 V, or discharged less than 2 ... 3 V. Also, the protection circuit saves from short circuits by disconnecting the bank from the consumer at the time of the short circuit.
It has a DW01 chip and an assembly of two MOSFET transistors (M1, M2) SM8502A. There are other markings, but the circuitry is similar to this one and works similarly.
Cell Phone Battery Charge Controller.
Controller circuit
Another controller circuit.
The main thing is not to confuse the polarity of soldering the controller with the bed and the controller with charging. On the controller board, the “+” and “-” contacts are indicated.
In the bed near the positive contact, it is desirable to make a clearly visible pointer, with red paint or a self-adhesive film, in order to avoid reversal.
Put it all together and that's what happened.
Charges great. When the voltage reaches 4.2 volts, the controller disconnects the battery from charging, and the LED switches from red to green. Charging is complete. You can charge other Li-Ion batteries, just use a different bed. Good luck to all.
Almost all modern lithium-ion batteries have excellent power consumption, as well as high small-sized indicators. It is with their help that it is possible to power high-power devices with the greatest efficiency. And it’s not necessary to buy a ready-made charger in the store for this, because there is a more budget option that radio amateurs will especially like - to collect a charger for lithium-ion batteries with their own hands.
Precautions: overcharge is not acceptable
It is extremely important to remember one simple thing before assembling the battery for batteries - lithium batteries are strictly forbidden to recharge. They have very strict requirements for charging and operation, so they can not be charged to a voltage of more than 4.2 V. And even better, be guided by information about the safe threshold for each individual can. By the way, even a lower threshold, which is considered acceptable for this instance, can be indicated there.
Even better, if you are going to do the charging for lithium batteries with your own hands, check the materials and equipment used several times. If you have doubts about the accuracy of the readings of your voltmeter or the origin of the cans, as well as the maximum allowable power of their charge, it is better to set the threshold even less. It will be optimally between 4.1–4.15 V. In this case, charging batteries that do not have a built-in protection board will be safe for you.
Otherwise, there is a high probability of strong heating and swelling of the cans, copious gas evolution with a sharp unpleasant odor, and even their subsequent explosion. Check everything several times before proceeding with assembly and charging.
Do-it-yourself battery charger for lithium batteries
To assemble a charger for lithium batteries, one simplified circuit will suffice. The memory created by such a scheme will practically not need to be regulated, but for work you will need:
- Set Uout \u003d 4.2 V without a connected battery (using R8);
- Set charging current using R6 and R
In the role of an indicator of the memory, the “charge” type LED will perfectly prove itself. It will highlight if the battery connected to it is discharged, and will go out when it is fully charged.
Do-it-yourself lithium battery charging collection sequence is as follows:
- choose a suitable case;
- attach to it a power supply (5 V) and elements of the indicated circuit (be sure to in the correct order);
- take brass and cut two strips from it, fasten them to the nests;
- using a nut, set the distance between the contacts and the battery that you are going to connect;
- attach the switch if you want to subsequently be able to change the polarity on the sockets (if not, leave it as it is).
How to assemble a charge for do-it-yourself lithium-ion batteries?
Since Li-Ion batteries are sensitive to abrupt voltage during charging, special microchips are built into branded batteries. They provide voltage control and do not allow exceeding permissible limits. Therefore, in order to assemble the charge for 18650 lithium batteries with your own hands, you need a more complex circuit than the one mentioned above.
This battery option will be much more difficult to create than the previous one and at home it is possible only if there are certain skills and relevant experience. In theory, you can get a charger, which in terms of characteristics will not be inferior to branded batteries. But in practice this is far from always the case.
Surely, every radio amateur had a problem connecting lithium batteries in series, noticed that one sat down quickly and the other was still holding a charge, but because of another, the entire battery did not give the necessary voltage. This is due to the fact that when charging the entire battery pack, they are not charged evenly, and some of the batteries gain full capacity and some are not. This leads not only to a fast discharge, but also to the failure of individual elements, because of the constant not before charging.
It is quite simple to fix the problem, each battery cell needs a so-called balancer, a device that, after fully charging the battery, blocks its further recharging, and by the control transistor circulates the charging current past the cell.
The balancer circuit is quite simple, assembled on a precision controlled zener diode TL431A, and a direct conductivity transistor BD140.
After long experiments, the circuit changed a little, 3 sequentially connected diodes 1N4007 were installed in the place of the resistors, the balancer began to work as it seemed to me more stable, the diodes warm up significantly when charging, this should be taken into account when wiring the board.
Principle of operation very simple, as long as the voltage on the cell is less than 4.2 volts, charging is in progress, the controlled zener diode and transistor are closed and do not affect the charging process. As soon as the voltage reaches 4.2 volts, the zener diode starts to open the transistor, which shunts the battery through resistors with a total resistance of 4 Ohms, thereby preventing the voltage from rising above the upper threshold of 4.2 volts, and makes it possible for the remaining batteries to charge. A transistor with resistors quietly passes a current of about 500 mA, while it heats up to 40-45 degrees. As soon as the LED on the balancer lights up, the battery that is connected to it is fully charged. That is, if you have 3 batteries connected, then the end of the charge should be considered the LEDs on all three balancers.
Customization it is very simple, we apply a voltage of 5 volts to the board (without battery) through a resistor of about 220 Ohms, and measure the voltage on the board, it should be 4.2 volts, if it differs then we select a 220 kOhm resistor in small limits.
Charging voltage should be applied approximately 0.1-0.2 volts more than the voltage on each element in a charged state, for example: we have 3 series-connected batteries of 4.2 volts in a charged state, the total voltage is 12.6 volts. 12.6 + 0.1 + 0.1 + 0.1 \u003d 12.9 volts. It should also limit the charge current to 0.5 A.
As an option for the voltage and current stabilizer, you can use the LM317 chip, the inclusion of a standard datasheet, the circuit is as follows.
The transformer must be selected with the calculation - the voltage of a charged battery + 3 volts for alternating, for the LM317 to work correctly. For example, you have a 12.6 volt + 3 volt battery \u003d a transformer needs 15-16 volts of alternating voltage.
Since the LM317 is a linear regulator, and the voltage drop on it turns into heat, we must install it on the radiator.
Now a little about how to calculate the divisor R3-R4 for voltage stabilization, but very simple by the formula R3 + R4 \u003d (Vo / 1.25-1) * R2, the value of Vo is the voltage of the end of charge (maximum output after the stabilizer).
Example: we need to get 12.9 volts for 3 output. batteries with balancers. R3 + R4 \u003d (12.9 / 1.25-1) * 240 \u003d 2476.8 Ohms. which is approximately equal to 2.4 kΩ + we have a tuning resistor for fine tuning (470 Ohms), which will allow us to set the calculated output voltage without any problems.
Now the calculation of the output current, the resistor Ri is responsible for it, the formula is simple Ri \u003d 0.6 / Is, where Iz is the maximum charge current. For example, we need a current of 500 mA, Ri \u003d 0.6 / 0.5A \u003d 1.2 Ohms. It should be borne in mind that a charging current flows through this resistor, because its power should be taken 2 watts. That's all, I don’t lay out the boards, they will be when I collect the charger with a balancer for my metal detector.
How to charge a lithium-ion battery and why is it even necessary? Our modern devices work thanks to the availability of autonomous power sources. And it doesn’t matter what the devices are: electric smartphones or laptops. That is why it is so important to know the answer to the question of how to properly charge a lithium-ion battery.
A little bit about what a lithium-ion battery is
Autonomous power sources, which are used in modern smartphones and other devices, are usually divided into several different groups. There are a lot of them. Take the same But it is in portable technology, that is, in smartphones and laptops, that most often they install lithium-ion batteries (the English designation is Li-Ion). The reasons that led to this are of a different nature.
The advantages of these types of batteries
First of all, it should be noted how simple and cheap the production of these energy sources is. Their additional advantages are excellent performance characteristics. Self-discharge losses are a very small indicator, and this also played a role. But the supply of cycles for charging and discharging is very, very large. Together, all this makes lithium-ion batteries the leaders among other similar devices precisely in the field of their use in smartphones and laptops. Although there are exceptions to the rules, they make up about 10 percent of the total number of cases. That is why many users are asking how to properly charge a lithium-ion battery.
Important and interesting facts
The smartphone battery has its own specific features. Therefore, you need to know certain rules and be familiar with the relevant instructions even before you begin to engage in the process of forced charging or discharging. It should be noted first of all that most batteries of this type are specially equipped with an additional control device. Its use is due to the need to keep the charge at a certain level (which is also called critical). Thus, the control device, which is also integrated in the battery for a smartphone, does not allow us to cross that fateful line, after which the battery simply “dies”, as service technicians like to say. From the point of view of physics, everything looks as follows: with the reverse process (critical discharge), the voltage of a lithium-ion battery simply drops to zero. In parallel, the current flow is blocked.
How to properly charge digital technology based on this source of battery life
If your smartphone is powered by a lithium-ion battery, then the device itself needs to be put on charge when the battery indicator displays about such numbers: 10-20 percent. The same is true for phablets and tablets. This is a short answer to the question of how to properly charge a lithium-ion battery. It should be added that even when reaching a 100% nominal charge, the device must be kept connected to the mains for another one to two hours. The fact is that the devices incorrectly interpret charging, and 100 percent that a smartphone or tablet gives out, in fact there are no more than 70-80 percent.
If your device is equipped with a lithium-ion battery, you should know some of the subtleties of its operation. This will be very useful in the future, because, following them, you can extend the life of not only this element, but the entire device as a whole. So, remember, once every three months you need to carry out a complete discharge of the device. This is done for preventive purposes.
But we’ll talk about how to charge a discharged battery later. Now we just point out that a stationary computer and laptop are not able to provide a sufficiently high voltage when connecting a mobile device to these miracles of technology via a USB port. Accordingly, in order to fully charge the device from these sources, it will take a longer amount of time. Interestingly, one technique can extend the life of a lithium-ion battery. It consists in alternating charge cycles. That is, once you charge the device completely, at 100 percent, the second time - not completely (80 - 90 percent). And these two options alternate in turn. In this case, it can be used for lithium-ion batteries.
Terms of use
In general, lithium-ion power sources can be called unpretentious. We have already talked about this topic and found out that this characteristic, along with others, has become the reason for their widespread use in computer technology. However, even such a smart battery architecture does not fully guarantee their long-term performance. This term depends primarily on the person. But we are not required to do anything beyond. If there are five simple rules that we can remember forever, apply them successfully. In this case, the lithium-ion power source will last you a very, very long time.
Rule one
It lies in the fact that it is not necessary completely. It has already been said that such a procedure should be carried out only once every three months. Modern designs of these power sources do not carry a “memory effect." Actually, therefore, it is better to have time to put the device on charge before it completely “sits down”. By the way, the fact that some manufacturers of the corresponding products measure the service life of the products in the number of cycles is very remarkable. Top-class products can survive about six hundred cycles.
Second rule
It states that the mobile device needs a full discharge. It should be carried out every three months for prevention. On the contrary, irregular and unstable charging is able to shift the nominal marks of the minimum and maximum charge. Thus, the device into which this source of autonomous work is built in begins to receive untruthful information about how much energy is actually left. And this, in turn, leads to incorrect calculations of energy consumption.
Preventive discharge is designed to prevent this. When it does, the control circuit will automatically reset the minimum charge value. However, there are tricks. For example, after a complete discharge, it is necessary to “hammer to the eyeballs” a power source, holding it for an additional 12 hours. In addition to the ordinary electric network and wire, we will not need anything else to charge in this matter. But the battery operation after preventive discharge will become more stable, and you can immediately notice it.
Rule three
If you are not using your battery, you still need to monitor its condition. At the same time, the temperature in the room where you store it should preferably be no more and no less than 15 degrees. It is clear that it is not always possible to achieve exactly such a figure, but nevertheless, the smaller the deviation from this value, the better. It should be noted that the battery itself should be charged at 30-50 percent. Such conditions will allow holding the power supply without serious damage for a long time. Why shouldn’t it be fully charged? And because the battery “clogged to the eyeballs” loses a fairly large part of its capacity due to physical processes. If the power source is stored for a long time in a discharged state, then it becomes practically useless. And the only place where it really comes in handy is the trash. The only way, albeit unlikely, is to restore lithium-ion batteries.
Rule Four
The price for which falls in the range from several hundred to several thousand rubles, should be charged only with the help of original devices. This applies to mobile devices to a lesser extent, since adapters are already included in their package (if you buy them in the official store). But in this case they only stabilize the supplied voltage, and the charger, in fact, is already built into your device. Which, incidentally, cannot be said about camcorders and cameras. This is what this is all about, here the use of third-party devices when charging batteries can cause noticeable harm.
Rule Five
Watch the temperature. Lithium-ion batteries can resist thermal stress, but overheating is fatal to them. Yes, and low temperatures for the power source - this is not the best that can be. Although the big danger comes from the overheating process. Remember that the battery should not be exposed to direct sunlight. The range of temperatures and their permissible values \u200b\u200bstarts at - 40 degrees and ends at + 50 degrees Celsius.
Today, special batteries are used for mobile, household appliances and tools. They differ in operational characteristics. In order for the battery to work for a long time, without failures, the requirements of the manufacturers of the products presented must be taken into account.
One of the most popular types today are Li-Ion batteries. How to properly charge this type of battery, as well as the features of its operation should be considered in detail before operating the device.
general characteristics
One of the most common types of batteries today is the Li-Ion type. Such devices have a relatively low cost. However, they are undemanding to operating conditions. In this case, the user rarely raises the question of how to properly charge a Li-Ion 18650 battery of a cylindrical shape or another variety.
Most often, the presented batteries are installed in smartphones, laptops, tablets and other similar devices. The presented batteries are characterized by durability and reliability. They are not afraid of complete discharge.
One of the main features of the presented products is the absence of a “memory effect". These batteries can be charged at almost any convenient time. A “memory effect" occurs when the battery is not fully discharged. If a small amount of charge remains in it, over time, the battery capacity will begin to decline. This will lead to insufficient power supply of the equipment. In lithium-ion batteries, the “memory effect" is minimized.
Design
The design of the lithium-ion battery depends on the type of device for which it is intended. A battery called a “bank” is used for a mobile phone. It has a rectangular shape and includes one structural element. Its rated voltage is 3.7 V.
The battery of the presented type for a laptop has a completely different design. There can be several separate battery cells in it (2-12 pieces). Each of them has a cylindrical shape. These are Li-Ion 18650 batteries. How to charge them properly is indicated in detail by the manufacturer of the equipment. This design incorporates a special controller. It looks like a microchip. The controller controls the charging procedure, does not allow exceeding the nominal value of the battery capacity.
Modern batteries for tablets and smartphones also include a charge control function. This significantly extends battery life. It is protected from various adverse factors.
Charging Features
Considering how to properly charge the Li-Ion batteries of a phone, laptop and other equipment, you need to pay attention to the features of the presented device. It should be said that lithium-ion batteries do not tolerate deep discharge and overcharge. This is controlled by a special device that is added to the design (controller).
It is ideal to maintain the charge of the type of battery presented at a level of 20 to 80% of full capacity. This is monitored by the controller. However, experts do not recommend leaving the device connected to charging constantly. This significantly reduces battery life. In this case, a constant load acts on the controller. Over time, its functionality may decrease due to this.
In this case, the controller also will not allow deep discharge. He just disconnects the battery at some point. This protective function is essential. Otherwise, the user could accidentally recharge or discharge the battery too much. Also in modern-style batteries, high-quality protection against overheating is provided.
Battery Principle
To understand how to properly charge a Li-Ion battery (new or used), you need to consider the principle of its operation. This will assess the need to control the level of discharge and charge of the device.
Lithium ions in the battery of the present type move from one electrode to another. In this case, an electric current appears. Electrodes can be made of different materials. This indicator to a lesser extent affects the operational characteristics of the device.
Lithium ions grow on the crystal lattice of electrodes. The latter, in turn, change their volume and composition. When the battery is charged or discharged, it becomes larger on one of the electrodes. The higher the load on the metal structural elements that lithium exerts, the shorter the life of the device will be. Therefore, it is better not to allow a high percentage of ion deposition on one or the other electrode.
Charging options
Before using the battery, you need to consider how to properly charge the Li-Ion battery of a smartphone, tablet and other equipment. There are several ways to do this.
One of the most correct decisions will be the use of a charger. It is supplied with every manufacturer by electronic equipment.
The second option is to charge the battery from a desktop computer connected to a household network. A USB cable is used for this. In this case, the charging procedure will be longer than when using the first method.
You can perform this procedure using the cigarette lighter in the car. Another less popular way is to charge a lithium-ion battery using a universal device. It is also called the "frog." Most often, such devices are used to recharge the batteries of smartphones. The contacts of this device can be adjusted in width.
Charge a new battery
The new battery must be put into operation correctly. To do this, the phone, tablet or other equipment must be completely discharged. Only when the device turns off can it be connected to the network. The controller will not allow the battery to discharge too much. It is he who turns off the device when the battery loses capacity to a predetermined level.
Next, you need to connect electrical equipment to the network using a standard charger. The procedure is performed until the indicator lights up in green. You can leave the device on the network for a few more hours. This procedure is carried out several times. In this case, you do not need to specifically discharge the phone, tablet or laptop.
Normal charge
Knowing how to properly charge Li-Ion batteries can significantly extend the battery life. Experts recommend the correct procedure for this process for a new battery. After that, it is not advisable to discharge the battery completely. When the indicator shows that the battery capacity has a charge of only 14-15%, it must be connected to the network.
At the same time, it is also not recommended to use other devices to fill the battery capacity, except for the regular one. It has the most acceptable current ratings available for a specific battery model. Other options can be used only in case of emergency.
Calibration
There is one more nuance that you need to learn when studying the question of how to properly charge Li-Ion batteries. Experts recommend periodically calibrating this device. It is held every three months.
First, in normal mode, you need to discharge the electrical equipment before it turns off. Then it is connected to the network. Charging continues until the indicator lights up green (battery is 100% charged). This procedure must be performed for the controller to work properly.
In such a procedure, the battery circuit board determines the limits for charging and discharging. This is necessary to ensure the normal operation of the controller, avoiding failures. In this case, a standard charger is used, which is supplied by the manufacturer complete with a phone, tablet or laptop.
Storage
In order for the battery to work as long and efficiently as possible, you must also consider how to properly charge the Li-Ion battery for storage. In some cases, a situation may arise when the device for powering equipment is temporarily not in use. In this case, it must be properly prepared for storage.
The battery is charged up to 50%. In this state, it can be stored for a long time. However, the ambient temperature should be about 15 ºС. If it increases, the rate of loss of battery capacity will increase.
If the battery needs to be stored for a sufficiently long time, it needs to be completely discharged and charged once a month. The battery gains 100% of its predetermined capacity. Then the device is discharged again and charged up to 50%. If you regularly perform this procedure, you can store the battery for a very long time. After that, it will be fully operational.
Having considered how to properly charge Li-Ion batteries, you can significantly extend the life of this type of battery.
