What voltage to charge li ion. How to properly charge a new li-Ion battery - tips for the user. Slow charging method

If you pick any battery from cell phone, then you can find that a small printed circuit board. This is the so-called protection circuit, or Protection IC.

Due to their characteristics, lithium batteries require constant monitoring. Let's take a closer look at how the protection circuit works and what elements it consists of.

The ordinary circuit of a lithium battery charge controller is small fee, on which it is mounted electronic circuit from SMD components. The controller circuit of 1 cell (“bank”) at 3.7V, as a rule, consists of two microcircuits. One control chip, and the other executive - an assembly of two MOSFET transistors.

The photo shows a charge controller board from a 3.7V battery.

A chip labeled DW01-P in a small package is essentially the “brain” of the controller. Here is a typical circuit diagram for connecting this microcircuit. In the diagram G1 is a lithium-ion or polymer battery cell. FET1, FET2 are MOSFET transistors.

Tsokolevka, appearance and pin assignment of the DW01-P chip.

MOSFET transistors are not included in the DW01-P microcircuit and are made in the form of a separate microcircuit assembly of 2 N-type MOSFET transistors. Typically an assembly labeled 8205 is used, and the package can be either 6-pin (SOT-23-6) or 8-pin (TSSOP-8). The assembly may be labeled as TXY8205A, SSF8205, S8205A, etc. You can also find assemblies marked 8814 and similar ones.

Here is the pinout and composition of the S8205A chip in the TSSOP-8 package.

Two field-effect transistors are used to separately control the discharge and charge of the battery cell. For convenience, they are manufactured in one case.

The transistor (FET1) that is connected to the OD pin ( Overdischarge) DW01-P microcircuit, monitors battery discharge - connects/disconnects the load. And the one (FET2) that is connected to the OC pin ( Overcharge) – connects/disconnects the power source (charger). Thus, by opening or closing the corresponding transistor, you can, for example, turn off the load (consumer) or stop charging the battery cell.

Let's look at the logic of the control chip and the entire protection circuit as a whole.

Overcharge Protection.

As you know, overcharging a lithium battery above 4.2 - 4.3V is fraught with overheating and even explosion.

If the cell voltage reaches 4.2 - 4.3V ( Overcharge Protection Voltage – VOCP), then the control chip closes transistor FET2, thereby preventing further charging of the battery. The battery will be disconnected from the power source until the voltage across the cell drops below 4 - 4.1V ( Overcharge Release Voltage – V OCR) due to self-discharge. This is only the case if there is no load connected to the battery, for example it is removed from a cell phone.

If the battery is connected to a load, then the FET2 transistor opens again when the voltage across the cell drops below 4.2V.

Overdischarge Protection.

If the battery voltage drops below 2.3 - 2.5V ( Overdischarge Protection Voltage – VODP), then the controller turns off the MOSFET transistor of the FET1 discharge - it is connected to the DO pin.

There is quite interesting condition. Until the voltage on the battery cell exceeds 2.9 - 3.1V ( Overdischarge Release Voltage – V ODR), the load will be completely disconnected. There will be 0V at the controller terminals. Those who are little familiar with the logic of the protective circuit may mistake this state of affairs for the “death” of the battery. Here's just a small example.

Miniature Li-polymer battery 3.7V from an MP3 player. Composition: control controller – G2NK (series S-8261), assembly of field-effect transistors – KC3J1.

The battery has discharged below 2.5V. The control circuit disconnected it from the load. The controller output is 0V.

Moreover, if you measure the voltage on the battery cell, then after disconnecting the load it increased slightly and reached a level of 2.7V.

In order for the controller to reconnect the battery to the “outside world”, that is, to the load, the voltage on the battery cell must be 2.9 - 3.1V ( V ODR).

A very reasonable question arises here.

The diagram shows that the Drain terminals of transistors FET1, FET2 are connected together and are not connected anywhere. How does current flow through such a circuit when overdischarge protection is triggered? How can we recharge the battery “jar” again so that the controller turns on the discharge transistor – FET1 – again?

If you rummage through the datasheets for Li-ion/polymer protection chips (including DW01-P, G2NK), then you can find out that after the deep discharge protection is triggered, the charge detection circuit operates - Charger Detection. That is, when the charger is connected, the circuit will determine that the charger is connected and allow the charging process.

Charging to a level of 3.1V after a deep discharge of a lithium cell can take a very long time - several hours.

To restore a lithium-ion/polymer battery, you can use special devices, for example, the Turnigy Accucell 6 universal charger. I have already talked about how to do this here.

It was with this method that I managed to restore a Li-polymer 3.7V battery from an MP3 player. Charging from 2.7V to 4.2V took 554 minutes and 52 seconds, which is more than 9 hours! This is how long a “recovery” charge can last.

Among other things, the functionality of lithium battery protection microcircuits includes overcurrent protection ( Overcurrent Protection) and short circuit. Overcurrent protection is triggered in the event of a sudden drop in voltage a certain amount. After this, the microcircuit limits the load current. If there is a short circuit (short circuit) in the load, the controller completely turns it off until the short circuit is eliminated.

Li-ion battery controller circuit
Diagram of a lithium-ion battery controller Design and principle of operation of a Li-ion/polymer battery protective controller If you pick apart any battery from a cell phone, you can

Probably, most radio amateurs, over the years, start a box in which they put it “for later.” lithium batteries from the untimely deceased (drowned, fallen from the balcony, chewed by Buddy) mobile phones and cameras. They lie in a box and wait for their time... But the hour still doesn’t come. The reason is simple - to use battery in the same flashlight you need to do it charging controller, but for some reason they didn’t deliver charging chips to the local radio store... Yes, that’s a problem.

So what should a poor radio amateur do? It’s all very simple - you can get by with “pasture” using what is hidden from the eyes of the average user. Namely, the protection board, which is carefully hidden inside each lithium-ion or lithium polymer battery. Without it they are not allowed to use batteries in household appliances due to the exceptional activity of lithium. If you take it apart battery from mobile phone , we will find this simple device inside:

That's what it is battery protection board. This board contains a two-level comparator chip and field-effect transistor. When the voltage drops by battery below 3V or rising above 4.25V, this comparator turns off the transistor and isolates battery from the outside world, thereby protecting against damage.

I had the idea to try to use these properties of the protection board to control the process charging phone battery from standard USB ports computer (which as a bonus has a 500mA current limiter). So we get ax soup. More precisely, charging “out of nothing.” All that remains is to somehow display to the user the progress (and completion) of the process charging. Below is scheme this node.

It works very simply. When connected to USB port charging starts and lights up Light-emitting diode. The charging current is limited by the computer port and resistors on the board. When the voltage reaches battery 4.25V the comparator of the protection board is triggered and breaks the charging circuit. The LED will go off. In the first charging option, I used a button to start the charging process. But it turned out that a 100nF capacitor was enough to initially open the field-effect transistor. The circuit is very simple and starts working without adjustment.
The board file can be downloaded in the section "File Catalog"

If, while repeating this design, you have any questions or ideas for improving it, write to me in the online form your thoughts on this matter.

How to charge a lithium ion battery without a controller
How to charge a lithium-ion battery without a controller Probably, most radio amateurs, over the years, start a box in which lithium batteries from

If you are interested in how to charge a lithium-ion battery, then you have come to the right place.

Modern mobile devices require an independent power source.

Moreover, this is true both for “high technologies” such as smartphones and laptops, and for more simple devices, say, electric drills or multimeters.

There are many different types of batteries. But for portable equipment, Li-Ion is most often used.

The relative ease of production and low cost led to such wide distribution.

Excellent performance characteristics, plus low self-discharge and a large reserve of charge-discharge cycles, also contributed to this.

Important! For greater convenience, most of these batteries are equipped with a special monitoring device that prevents the charge from crossing critical levels.

During a critical discharge, this circuit simply stops supplying voltage to the device, and when it exceeds permissible level charge switches off the incoming current.

Moreover, after reaching the nominal 100%, charging should last another one and a half to two hours.

This is necessary because the battery will actually be charged to 70–80%.

When charging from a laptop or desktop computer It must be taken into account that the USB port is unable to provide a sufficiently high voltage, therefore, the process will take more time.

Alternating cycles of full and incomplete (80–90%) charging will extend the life of the device.

Despite such a smart architecture and general unpretentiousness, following some rules for using batteries will help extend their life.

To prevent the device’s battery from “suffering,” it is enough to follow simple recommendations.

Rule 1. No need to completely discharge the battery

Modern lithium-ion batteries do not have a “memory effect”. Therefore, it is better to charge them before the moment of complete discharge comes.

Some manufacturers measure the service life of their batteries by the number of charge cycles from zero.

The highest quality products can withstand up to 600 such cycles. When charging the battery with 10–20% remaining, the number of cycles increases to 1700.

Rule 2. Complete discharge still needs to be done once every three months.

With unstable and irregular charging, the average maximum and minimum charge levels in the previously mentioned controller are lost.

This leads to the device receiving incorrect information about the amount of charge.

Preventive discharge will help prevent this. When the battery is completely discharged, the minimum charge value in the control circuit (controller) will be reset to zero.

After this, you need to charge the battery to capacity, keeping it connected to the network for eight to twelve hours.

This will update the maximum value. After such a cycle, the battery operation will be more stable.

Rule 3: An unused battery should be stored with a small amount of charge.

Before storage, it is better to charge the battery by 30–50% and store it at a temperature of 15 0 C. In such conditions, the battery can be stored for quite a long time without much damage.

A fully charged battery will lose a significant portion of its capacity during storage.

And completely discharged ones after long-term storage will only have to be sent for recycling.

Rule 4. Charging must be done only with original devices

It is noteworthy that the charger itself is built into the design mobile device(phone, tablet, etc.).

In this case, the external adapter acts as a rectifier and voltage stabilizer.

The use of third-party “charging” can negatively affect their condition.

Rule 5. Overheating is detrimental to Li-Ion batteries

High temperatures have an extremely negative impact on the design of batteries. Low ones are also destructive, but to a much lesser extent.

This must be kept in mind when using lithium-ion batteries.

The battery must be protected from direct sunlight and used at a distance from heat sources.

The permissible temperature range is between -40 0 C and +50 0 C.

Rule 6. Charging batteries using a “frog”

Using uncertified chargers is unsafe. In particular, common Chinese-made “frogs” often ignite during charging.

Before using such a universal charger, you must check the maximum permissible values ​​indicated on the packaging.

So, attention must be paid to the maximum capacity.

If the limit is less than the battery capacity, then at best it will not be fully charged.

When the battery is connected, the corresponding indicator on the frog body should light up.

If this does not happen, it means the charge is critically low or the battery is faulty.

When the charger is connected to the network, the connection indicator should light up.

Another diode is responsible for achieving maximum charge, which is activated under appropriate conditions.

Tips for using Li-ion batteries

How to charge and maintain a lithium ion battery: 6 simple rules

How to charge and maintain a lithium-ion battery: 6 simple rules
How to charge and maintain a lithium-ion battery: 6 simple rules If you are interested in how to charge a lithium-ion battery, then you have come to the right place. Modern mobile devices

13.10.2018

Modern devices for working in offline mode equipped with batteries - most often these are lightweight, inexpensive and easy-to-use Li-Ion batteries. There are many tips on the Internet on how to properly charge a new li-Ion battery, the reliability of which is questionable.

Charging a lithium battery for the first time - common myths

When purchasing a new device or battery, the owner will certainly encounter the following myths:

1. the battery of a newly purchased gadget must be discharged to zero 2-3 times;
2. the first charge should last at least 16 hours;
3. Under no circumstances should you interrupt the first charging of the battery.

The first myth is associated with the device’s memory, supposedly it remembers the capacity from which charging began. In fact, this is only true for Ni-Cd batteries, but has nothing to do with the first charge of a lithium battery.

The situation is the same with charge duration - alkaline batteries cost at least 16 hours to charge. The duration of lithium charging depends on its capacity and discharge level - the charger will turn off the current supply when it reaches full charge.

Interrupting the first charge has no effect on the battery capacity. Figuratively, this can be compared to filling a bucket with water: it makes no difference whether you pour it at once or a couple of liters at a time. We wrote about what really affects the service life of a battery in the article Service life of lithium-ion batteries.

How to properly charge a new li-Ion battery

Devices of this type do not have a “memory effect,” which refers to the loss of capacity that occurs when charging an incompletely discharged battery. Nickel-cadmium and nickel-metal hydride batteries, which were used in already outdated push-button phones. Therefore, there are no special tips, confirmed by experts, on how to charge lithium-ion batteries for the first time. Completely discharging a li-Ion battery for the purpose of subsequent “pumping” is even harmful to it.

After all, the battery is designed by the manufacturer for a certain number of operating cycles. A new cycle begins when the zero mark is reached. That is, the more often he reaches full discharge, the faster it will lose capacity, losing the ability to store the required amount of energy. From here it becomes clear how to charge and discharge lithium-ion batteries for the first time and further in order to increase their service life - the discharge level should not exceed 10%.

In order for the battery to last for a long time, when charging for the first time you need to follow simple rules:

1. put the device on charge when it reaches 10-20% charge;
2. after the signal about full charge appears, do not rush to turn it off - you need to let it stand on the charge for another half hour (at this time charging occurs with a low current);
3. charge only with original charger;
4. charge in a room where the temperature is above +10°.

To ensure that the device is charging correctly, during the first charge you should periodically check the temperature of the charger, battery and all connectors and wires. Strong heating of at least one element indicates a malfunction. In general, the first charging of this type of battery does not have any differences from the others - you need to follow the general rules for charging batteries.

The charging and discharging processes of any battery occur in the form of a chemical reaction. However, charging lithium-ion batteries is an exception to the rule. Scientific research shows the energy of such batteries as the chaotic movement of ions. The statements of pundits deserve attention. If the science is to charge lithium-ion batteries correctly, then these devices should last forever.

Scientists see evidence of loss of useful battery capacity, confirmed by practice, in ions blocked by so-called traps.

Therefore, as is the case with other similar systems, lithium-ion devices are not immune to defects during their use in practice.

Chargers for Li-ion designs have some similarities to devices designed for lead-acid systems.

But the main differences between such chargers are seen in the supply of increased voltages to the cells. In addition, there are tighter current tolerances, plus the elimination of intermittent or floating charging when the battery is fully charged.

A relatively powerful power device that can be used as an energy storage device for alternative energy source designs
Cobalt-blended lithium-ion batteries are equipped with internal protective circuits, but this rarely prevents the battery from exploding when overcharged.

There are also developments of lithium-ion batteries, where the percentage of lithium has been increased. For them, the charge voltage can reach 4.30V/I and higher.

Well, increasing the voltage increases the capacity, but if the voltage goes beyond the specification, it can lead to destruction of the battery structure.

Therefore, for the most part, lithium-ion batteries are equipped with protective circuits, the purpose of which is to maintain the established standard.

Full or partial charge

However, practice shows: most powerful lithium-ion batteries can accept a higher voltage level, provided that it is supplied for a short time.

With this option, the charging efficiency is about 99%, and the cell remains cool during the entire charging time. True, some lithium-ion batteries still heat up by 4-5C when they reach a full charge.

This may be due to protection or due to high internal resistance. For such batteries, the charge should be stopped when the temperature rises above 10ºC at a moderate charge rate.

Lithium-ion batteries in the charger are being charged. The indicator shows the batteries are fully charged. Further process threatens to damage the batteries

Full charging of cobalt-blended systems occurs at a threshold voltage. In this case, the current drops by up to 3-5% of the nominal value.

The battery will show a full charge even when it reaches a certain capacity level that remains unchanged for a long time. The reason for this may be increased self-discharge of the battery.

Increasing charge current and charge saturation

It should be noted that increasing the charge current does not speed up the achievement of a full charge state. Lithium will reach peak voltage faster, but charging until the capacity is completely saturated takes longer. However, charging the battery at high current quickly increases the battery capacity to approximately 70%.

Lithium-ion batteries do not require a full charge, as is the case with lead-acid devices. Moreover, this charging option is undesirable for Li-ion. In fact, it is better to not fully charge the battery, because high voltage “stresses” the battery.

Selecting a lower voltage threshold or completely removing the saturation charge helps extend the life of the lithium-ion battery. True, this approach is accompanied by a decrease in the battery energy release time.

It should be noted here: household chargers, as a rule, operate at maximum power and do not support adjustment of the charging current (voltage).

Manufacturers of consumer lithium-ion battery chargers estimate a long service life of less than important factor than the costs of complicating circuit solutions.

Li-ion battery chargers

Some cheap household chargers often work using a simplified method. Charge a lithium-ion battery in one hour or less, without going to saturation charge.

The ready indicator on such devices lights up when the battery reaches the voltage threshold in the first stage. The state of charge is about 85%, which often satisfies many users.

This domestically produced charger is offered to work with different batteries, including lithium-ion batteries. The device has a voltage and current regulation system, which is already good

Professional chargers (expensive) are distinguished by the fact that they set the charging voltage threshold lower, thereby extending the life of the lithium-ion battery.

The table shows the calculated power when charging with such devices at different voltage thresholds, with and without saturation charge:

Charge voltage, V/per cell	Capacity at high voltage cut-off, %	Charging time, min	Capacity at full saturation, %
3.80	60	120	65
3.90	70	135	75
4.00	75	150	80
4.10	80	165	90
4.20	85	180	100

As soon as the lithium-ion battery begins to charge, there is a rapid increase in voltage. This behavior is comparable to lifting a load with a rubber band when there is a lag effect.

Capacity will eventually be gained when the battery is fully charged. This charge characteristic is typical for all batteries.

The higher the charging current, the brighter the rubber band effect. Low temperature or the presence of a cell with high internal resistance only enhances the effect.

The structure of a lithium-ion battery in its simplest form: 1- negative busbar made of copper; 2 — positive tire made of aluminum; 3 - cobalt oxide anode; 4- graphite cathode; 5 - electrolyte

Assessing the state of charge by reading the voltage of a charged battery is impractical. Measuring the open circuit (idle) voltage after the battery has been sitting for several hours is the best evaluation indicator.

As with other batteries, temperature affects idle speed in the same way it affects the active material of a lithium-ion battery. , laptops and other devices is estimated by counting coulombs.

Lithium-ion battery: saturation threshold

A lithium-ion battery cannot absorb excess charge. Therefore, when the battery is completely saturated, the charging current must be removed immediately.

A constant current charge can lead to metallization of lithium elements, which violates the principle of ensuring the safe operation of such batteries.

To minimize the formation of defects, you should disconnect the lithium-ion battery as quickly as possible when it reaches peak charge.

This battery will no longer take exactly as much charge as it should. Due to improper charging, it lost its main properties as an energy storage device.

As soon as the charge stops, the voltage of the lithium-ion battery begins to drop. The effect of reducing physical stress appears.

For some time, the open circuit voltage will be distributed between unevenly charged cells with a voltage of 3.70 V and 3.90 V.

Here, the process also attracts attention when a lithium-ion battery, which has received a fully saturated charge, begins to charge the neighboring one (if one is included in the circuit), which has not received a saturation charge.

When lithium-ion batteries need to be constantly kept on the charger in order to ensure their readiness, you should rely on chargers that have a short-term compensation charge function.

Charger with short-term compensation charge function turns on when the open circuit voltage drops to 4.05 V/I and turns off when the voltage reaches 4.20 V/I.

Chargers designed for hot-ready or standby operation often allow the battery voltage to drop to 4.00V/I and will only charge Li-Ion batteries to 4.05V/I rather than reaching the full 4.20V/I level.

This technique reduces physical voltage, which is inherently associated with technical voltage, and helps extend battery life.

Charging cobalt-free batteries

Traditional batteries have a nominal cell voltage of 3.60 volts. However, for devices that do not contain cobalt, the rating is different.

Thus, lithium phosphate batteries have a nominal value of 3.20 volts (charging voltage 3.65V). And new lithium titanate batteries (made in Russia) have a nominal cell voltage of 2.40V (charger voltage 2.85).

Lithium phosphate batteries are energy storage devices that do not contain cobalt in their structure. This fact somewhat changes the charging conditions for such batteries.

Traditional chargers are not suitable for such batteries, as they overload the battery with the risk of explosion. Conversely, a charging system for cobalt-free batteries will not provide sufficient charge to a traditional 3.60V lithium-ion battery.

Exceeded charge of lithium-ion battery

The lithium-ion battery operates safely within specified operating voltages. However, battery performance becomes unstable if it is charged above operating limits.

Long-term charging of a lithium-ion battery with a voltage above 4.30V, designed for an operating rating of 4.20V, is fraught with lithium metalization of the anode.

The cathode material, in turn, acquires the properties of an oxidizing agent, loses its stability, and releases carbon dioxide.

The pressure of the battery cell increases and if charging continues, the internal protection device will operate at a pressure between 1000 kPa and 3180 kPa.

If the pressure rise continues after this, the protective membrane opens at a pressure level of 3.450 kPa. In this state, the lithium-ion battery cell is on the verge of exploding and eventually does just that.

Structure: 1 - top cover; 2 - upper insulator; 3 - steel can; 4 - lower insulator; 5 — anode tab; 6 - cathode; 7 - separator; 8 - anode; 9 — cathode tab; 10 - vent; 11 - PTC; 12 — gasket

Triggering of the protection inside a lithium-ion battery is associated with an increase in the temperature of the internal contents. A fully charged battery has a higher internal temperature than a partially charged battery.

Therefore, lithium-ion batteries appear to be safer when charged at a low level. That is why the authorities of some countries require the use of Li-ion batteries in aircraft that are saturated with energy no more than 30% of their full capacity.

Battery internal temperature threshold at fully loaded is:

• 130-150°C (for lithium-cobalt);
• 170-180°C (for nickel-manganese-cobalt);
• 230-250°C (for lithium manganese).

It should be noted: lithium phosphate batteries have better temperature stability than lithium manganese batteries. Lithium-ion batteries are not the only ones that pose a danger in energy overload conditions.

For example, lead-nickel batteries are also prone to melting with subsequent fire if energy saturation is carried out in violation of the passport regime.

Therefore, using chargers that are perfectly matched to the battery is of paramount importance for all lithium-ion batteries.

Some conclusions from the analysis

Charging lithium-ion batteries has a simplified procedure compared to nickel systems. The charging circuit is straightforward, with voltage and current limits.

This circuit is much simpler than a circuit that analyzes complex voltage signatures that change as the battery is used.

The energy saturation process of lithium-ion batteries allows for interruptions; these batteries do not need to be fully saturated, as is the case with lead-acid batteries.

Controller circuit for low-power lithium-ion batteries. A simple solution and a minimum of details. But the circuit does not provide cycle conditions that maintain a long service life

The properties of lithium-ion batteries promise advantages in the operation of renewable energy sources (solar panels and wind turbines). As a rule, a wind generator rarely provides a full battery charge.

For lithium-ion, the lack of steady-state charging requirements simplifies the charge controller design. A lithium-ion battery does not require a controller to equalize voltage and current, as is required by lead-acid batteries.

All household and most industrial lithium-ion chargers fully charge the battery. However, existing lithium-ion battery charging devices generally do not provide voltage regulation at the end of the cycle.

Detailed description of 18650 lithium-ion batteries, making a charging device with your own hands, nuances of application.

TEST:

To see if you have enough information about your lithium-ion battery:

1. What was the main disadvantage of the first 18650 battery models?

a) They exploded due to lithium metal inside - with frequent charging, accumulations appeared on the element, leading to an explosion.

b) The battery was too bulky and inconvenient.

1. What problem have the manufacturers of modern 18650 models not yet gotten rid of?

a) The battery often overheats.
b) The battery quickly loses charge when exposed to negative temperatures.

1. In what temperature range is it desirable to store the battery?

a) + 10 – + 25 – ideal indicators. The battery does not tolerate extremely cold or hot rooms.

b) Store the battery at low temperatures when not in use.

c) At a temperature of +30-45 degrees.

1. Why can't I buy a charger made in China?

a) The case is too unreliable.
b) Low quality parts, correct assembly technology is not always followed.

1. At what charge level is it advisable to store the battery?

a) The 18650 should be stored at a charge level that does not fall below 50%. A complete discharge cannot be performed.

b) Not lower than 10%.

Answers:

1. a) The main disadvantage of the first models is the risk of explosion. Lithium metal grew overgrown with frequent charging and a short circuit occurred, leading to an explosion of the battery.
2. b) Modern batteries do not tolerate low temperatures well - the charge drops very quickly.
3. a) + 10 – + 25 – ideal indicators. Do not place the battery in other conditions.
4. b) Chinese manufacturers often use low-quality parts when assembling devices, so they fail. The correct assembly technology is not always followed.
5. a) If you plan to keep the battery idle for a long time, then make sure that the charge on it does not fall below 50%, otherwise the battery will deteriorate.

Li-ion battery

Owners of lithium-ion batteries The 18650 faces the question of what current to charge it with. There are also difficulties with proper operation; people do not know exactly what such batteries are afraid of, or how to increase their operating time.

To assemble an electronic cigarette or flashlight yourself, you must study all aspects work with lithium-ion power supply.

Definition: Li-ion battery is an electric current battery that has become widespread among consumer electronics since 1991. It was this year that Sony Corporation presented the product to the wider market.

Answers to 5 Frequently Asked Questions

1. What are lithium-ion batteries used for?

- As a power source. Such batteries are often used for various mobile phones, video cameras, laptops, for recharging electric vehicles or modern electronic cigarettes.

1. Do the models have any disadvantages?

— The main drawback of the model was that the first developments literally exploded. This is explained by the fact that manufacturers placed an anode consisting of lithium metal inside. When it happens a large number of charges and discharges, formations appear on the anode, leading to the short circuit of the electrodes. As a result, a fire occurs, and then an explosion. On this moment this problem is solved.

1. How was the problem with explosions solved?

— To make the structure safer, scientists replaced the core with graphite, and got rid of the problem with explosions. But there were still difficulties with the cathode caused by the cobalt oxide design. If the operational characteristics were violated, the explosions were repeated. That is why it was necessary to ensure that the device was not overcharged. It was extremely inconvenient for users to constantly monitor the charge level and the developers had to modify the device again. Modern models are safe. When developers began using lithium ferrophosphate batteries, they managed to get rid of this problem. Modern devices are manufactured in such a way that overcharging and overheating are impossible.

1. Do modern models have disadvantages?

— The charge is lost if the battery is exposed to low temperatures.

1. If you don't use the battery for a long time, will it deteriorate?

– If you do not lower the rarefaction level below 50%, it will not deteriorate.

3 benefits of battery

Lithium-ion batteries have a number of positive aspects, which is why they gained popularity:

1. Extra large capacity battery
2. Small self-discharge
3. No special maintenance required.

Charging – 5 nuances

Charger

Look at the picture of the original charger device. The charger designed for lithium-ion batteries is very similar to the lead-acid type of battery. The difference is that lithium-ion battery available high voltage on each bank and serious voltage tolerance requirements.

This is interesting! The battery is called a “can” because of its similarity to the aluminum cans used for soft drinks.

"Banks"

Most Popular Items nutrition with this form - 18650. The battery received this name because of its dimensions: diameter - 18 mm, height - 65 mm. When charging lead-acid batteries batteries, Minor inaccuracies in voltage indications are allowed. Nose 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 of Chinese chargers designed for batteries 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 strictly controlled. When the value is 4.2 Volts, immediately stop charging. But in the event that it is built into the jar controller, then you don’t have to worry about it, because the device will do everything on its own.

Chargers 4.2 Volt

As charger For a lithium-ion battery, a voltage stabilizer is used, limiting the current at the very beginning of charging. It is necessary to use an extremely 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, absent current, or its value is very small - around 5-7 mA.

Oxidation

When a battery rod is placed in graphite, then the voltage should not exceed 4.1 V per element. If this rule is neglected, the energy density will increase greatly and oxidation processes of the device will begin. As a result, the battery will fail. To avoid oxidation, modern models are equipped with additives - graphite in its pure form there is no inside. But similar models can still be found by chance.

How to properly charge Li-ion batteries. Parallel connection of batteries.

Homemade charger at home (with your own hands) - 1 circuit

For charging 18650 purchase a universal charger and constantly use a multimeter to find out the necessary parameters. But such a device is quite expensive. Minimum price– 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 shutdown battery All the parts used for assembly can be found in any radio amateur's garage. If something is missing, you can buy it at the nearest radio store. You will have to spend a maximum of 300 rubles on components.

If diagram assembled correctly, there is no need additional settings— it will be immediately ready for use.

You need to use the following electrical diagram:

Scheme

The positive thing is that if you install stabilizer to the desired radiator, then the battery is charged without fear that the charger will catch fire. But this certainly cannot be said about Chinese chargers, which suffer from this unpleasant consequence.

Operating principle – 4 nuances

• to start battery must be charged using direct current, which is determined by the resistance of resistor R4;
• after battery receives a voltage of 4.2 Volts, the device switches to DC charging;
• when the current drops to minimum values, the LED will stop lighting;
• current recharging lithium-ion battery, should not exceed 10% of the capacity of the entire battery. Thus, the service life of the batteries increases. If resistor R4 has a value 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

1. If battery will need to be left unused for some time, it is advisable to store the batteries separately from the device that they will power. If a cell is fully charged, it will lose some of its charge over time. In the case when the element is charged very little, or is completely discharged, its performance may completely disappear. This is especially noticeable during periods of long hibernation.
2. Storage 18650 should be carried out at a charge level that does not fall below 50%. Under no circumstances should the cell be allowed to be fully charged or overcharged. This equipment has no memory effect. Charging must be done until the charge is completely exhausted. This will extend the battery life.
3. Battery Do not leave in too cold or hot areas. Suitable storage temperature is + 10 - + 25 degrees Celsius. If you place the battery in the cold, not only will the operating time decrease, but the chemical system will also deteriorate. Everyone has probably noticed that when using a mobile phone in winter, the charge batteries falls sharply.

How to avoid 4 mistakes when using and charging a lithium-ion battery

1. In the event that you decide to recharge the lithium-ion battery using a store charger, 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.
2. If you want to assemble it yourself device, then to charge the battery you need to use a current that is 10% of the battery capacity. The percentage may be higher, but not exceed 20%.
3. When using ion batteries, do not violate the rules of storage and operation, otherwise overheating, fire and explosion may occur.
4. If you follow all the rules operation, as well as the correct storage conditions, the battery life will be extended.

Top 3 Best Chargers for 18650 Battery

To ensure high-quality battery charging, you should purchase good devices, which is already loved by many users.

1. Nitecore Digicharger D4 – suitable for charging multiple batteries at once. Extremely easy to use.
2. Nitecore i2 is one of best options modern devices. Clear and easy to use.
3. Basen B21 is a universal device for different types batteries

Today for mobile, household appliances, tools use special batteries. They differ in performance characteristics. In order for the battery to work for a long time, without failures, you need to take into account the requirements of the manufacturers of the presented products.

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 are relatively low in cost. At the same time, they are undemanding to operating conditions. In this case, the user rarely has a question about how to properly charge a cylindrical Li-Ion 18650 battery or another type.

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. The “memory effect” occurs when the battery is not completely discharged. If there is a small amount of charge left in it, the battery's capacity will begin to decrease over time. This will lead to insufficient power supply for the equipment. In lithium-ion batteries, the “memory effect” is minimized.

Design

The design of a lithium-ion battery depends on the type of device for which it is intended. A mobile phone uses a battery called a “jar”. It has a rectangular shape and includes one structural element. Its nominal voltage is 3.7 V.

The presented type of battery for a laptop has a completely different design. There may be several individual battery cells in it (2-12 pieces). Each of them has a cylindrical shape. These are Li-Ion 18650 batteries. The manufacturer of the equipment indicates in detail how to charge them correctly. This design includes a special controller. It looks like a microcircuit. The controller controls the charging procedure and does not allow the battery's rated capacity to be exceeded.

Modern batteries for tablets and smartphones also provide a charge control function. This significantly extends the battery life. It is protected from various adverse factors.

Charging Features

When considering how to properly charge Li-Ion batteries of a phone, laptop and other equipment, you need to pay attention to the operating features of the presented device. It should be said that lithium-ion batteries do not tolerate deep discharge and overcharging. This is controlled by a special device that is added to the design (controller).

It is ideal to maintain the charge of the presented type of battery at a level of 20 to 80% of full capacity. The controller monitors this. However, experts do not recommend leaving the device connected to charging all the time. This significantly reduces battery life. In this case, the controller is subject to a constant load. Over time, its functionality may decrease because of this.

At the same time, the controller will also not allow deep discharge. It will simply turn off the battery at a certain moment. This protective function is extremely necessary. Otherwise, the user could accidentally overcharge or over-discharge the battery. Modern batteries also provide high-quality protection against overheating.

Battery operating 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 allow you to assess the need to monitor the level of discharge and charge of the device.

Lithium ions in a battery of this type move from one electrode to another. In this case it appears electricity. Electrodes can be made of different materials. This indicator has a lesser impact on the performance characteristics of the device.

Lithium ions grow on the crystal lattice of the electrodes. The latter, in turn, change their volume and composition. When the battery is charged or discharged, there are more ions on one of the electrodes. The higher the load on metal structural elements that lithium places, the shorter the service life of the device will be. Therefore, it is better not to allow a high percentage of ions to settle 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 solutions would be to use a charger. It is supplied complete with electronic equipment by every manufacturer.

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 take longer than when using the first method.

You can perform this procedure using the cigarette lighter in your car. One less popular way is charging a lithium-ion battery using a universal device. It is also called "frog". Most often, such devices are used to recharge smartphone batteries. The contacts of this device can be adjusted in width.

Charging a new battery

The new battery must be put into operation correctly. To do this, your 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 prevent the battery from draining too much. It is he who turns off the device when the battery loses capacity to a predetermined level.

Next, you need to connect the electrical equipment to the network using a standard charger. The procedure is performed until the indicator lights up green. You can leave the device online for a few more hours. This procedure is carried out several times. There is no need to specifically discharge your phone, tablet or laptop.

Normal charging

Knowing how to properly charge Li-Ion batteries can significantly extend the life of the battery. Experts recommend following the correct procedure for this process for a new battery. After this, it is not advisable to completely discharge the battery. When the indicator shows that the battery capacity is only 14-15% charged, it needs to be connected to the network.

At the same time, it is also not recommended to use devices other than the standard one to fill the battery capacity. It has the maximum acceptable current values ​​permissible for specific model batteries. Other options should only be used if absolutely necessary.

Calibration

There is one more nuance that you need to know when studying the question of how to properly charge Li-Ion batteries. Experts recommend periodically calibrating this device. It is held once every three months.

First, in normal mode, you need to discharge the electrical equipment before turning it off. Next it is connected to the network. Charging continues until the indicator turns green (battery is 100% charged). This procedure must be performed for proper operation controller.

When carrying out such a procedure, the battery circuit board determines the charging and discharging limits. This is necessary to ensure normal operation of the controller and avoid failures. In this case, a standard charger is used, which is supplied by the manufacturer with the phone, tablet or laptop.

Storage

In order for the battery to work as long and efficiently as possible, you also need to consider the question of how to properly charge a 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 to 50%. In this state it can be stored for quite a long time. However, the ambient temperature should be around 15 ºC. If it increases, the rate at which the battery loses its capacity will increase.

If the battery needs to be stored for a sufficiently long time, it must be completely discharged and charged once a month. The battery reaches 100% of its specified capacity. Then the device is discharged again and charged to 50%. If this procedure is carried out regularly, the battery can be stored for a very long time. After this, it will be fully usable.

By considering how to properly charge Li-Ion batteries, you can significantly extend the life of this type of battery.