In recent years, the autonomy of equipment and digital technology has become one of the decisive factors in choosing one or another product model. Batteries in the form of battery packs play a crucial role at this site. Their small size, coupled with high operating potential, significantly expand the capabilities of the target device. It remains only to choose the appropriate type of battery. And if LiOn elements were recently popular, today developers are increasingly looking at LiPo blocks. Batteries of this type have a wide range of advantages, although they are not without disadvantages.

General information about the element

LiPo devices belong to the modern group, which led to their some similarity with ionic counterparts. The fundamental difference lies in the type of electrolyte used. If a gel electrochemical composition is used in LiIon cells, a polymer with a lithium-containing mixture is used in LiPo. The concept of a polymer power supply is based on the property of this electrolyte to provide a semiconductor effect when coupled with lithium. As a result, the electrochemical qualities significantly increase the operating efficiency of the LiPo battery. A description of the general principle of operation of polymer cells will be incomplete without classification by the types of electrolytic solutions that are used in such batteries. In addition to gel-polymer devices, dry electrolytes and non-aqueous saline solutions are also isolated. In the first case, the basis is polyethylene oxide with lithium salts, and in the second case, non-aqueous salt mixtures sorbed in the matrix of polymers with small pores.

Characteristics

One of the main performance indicators of the battery is energy intensity. So, compared to NiCd batteries, this figure for LiPo is exceeded by 4-5 times. At the same time, the number of cycles reaches 600, and the reduction in capacity is 20%. The next characteristic is the amount of discharge current, which may vary depending on the type of element. It is expressed in amps, and the letter "C" indicates the brand of LiPo discharge. Batteries, the characteristics of which are indicated by this value as 3C 1 Ah, have a current value of 3 A. This is the highest value inherent in typical cells. However, there are also models 8-10C, which belong to the category of fast-discharge.

When it comes to the ability to operate batteries in different temperature conditions, LiPo batteries have the largest range. According to the manufacturers, it ranges from -20 to 40 ° C. However, it is still not recommended to abuse the use of devices with such batteries in extreme temperatures.

Charge Features

You can charge the cells from DC sources until the battery enters the stabilized voltage mode. In other words, when the replenishment reaches 80%, you can stop the process, but not before. A full charge gains its potential after 2 hours. During this time, in particular, standard 12V LiPo batteries with a capacity of 1500 mAh are charged. When choosing, it should be borne in mind that this task can be performed both with a conventional “computer” device and with a special device for lithium batteries. Obviously, the second option is preferable, if only for reasons of compatibility. Also, depending on the model of the charger, the user can be able to display the amount of charge, data on voltage and current strength. A set of these indicators gives you full control over the charging process.

Positive reviews

Polymer electrolytes do not offer many advantages over ion batteries, but they are obvious when compared with older generation batteries. In practice, owners of devices with such batteries notice stable voltage maintenance, modest dimensions and large capacity. Suffice it to say that compact single-cell batteries are capable of operating mobile devices for several days with intensive use. In addition, LiPo batteries are characterized by a reduced memory effect. This means that the owner will incur less operating costs during the charging cycles. An important positive feature for ordinary consumers is environmental safety. So far, manufacturers are not able to make batteries that are completely devoid of toxic substances, but polymer models are the least dangerous in this regard.

Negative Feedback

The complete replacement of lithium-ion batteries is still hampered by the shortcomings of the polymer electrolyte, which, among other things, are reflected in normal use. First of all, it is a problem of aging. Such batteries do not "live" for a long time, which is especially noticeable on the example of the same mobile devices. After 3-4 years, the owners note a decrease in capacity. That is, the element remains operational, but the duration of work on a single charge is gradually reduced. Sensitive for many users and the price factor. The fact is that LiPo batteries, due to the need to integrate additional protective circuits, add significantly to the cost. Even compared to lithium-ion models, they cost 10-15% more.

Conclusion

The prospect of development of LiPo batteries is still ambiguous. The advantages that polymer electrolyte cells can already boast of today are quite enough for a modern user of mobile devices. However, their potential is significantly limited and it is quite possible that ionic competitors will be replaced. Still, 6S LiPo batteries with an increased discharge current are capable of delivering unprecedentedly high semiconductor performance. Of course, this applies to the segment of compact devices designed for autonomous portable equipment. Also, hopes with the future development of this direction are supported by the resistance of the element to external influences - including temperature. In terms of mechanical strength, they can also compete with a magnesium battery, but if we take into account the preservation of working electrochemical properties, then the LiPo separation will be much higher.

Lithium polymer (LiPo) batteries
Instructions for use and safety

Read and follow these instructions carefully before using the elements. Incorrect use of cells may result in significant heat generation, fire, explosion, damage or loss of cell capacity.

General instructions

Lithium polymer batteries (LiPo batteries for short) require special care. This is true for charging and discharging as well as storage and other operations. The following special instructions must be observed:

Improper handling can result in explosions, fire, smoke emission and danger of poisoning. In addition, failure to follow instructions and cautions may result in loss of performance and other disadvantages.

The battery capacity decreases with each charge/discharge. Storage at too high or too low temperatures can also lead to a gradual decrease in their capacity. In the design of the model, batteries after 50 cycles, subject to charging and discharging instructions, still provide 50-80% of the capacity of a new battery, which is achieved due to high discharge currents and motor induction currents. Battery packs must not be connected in series or in parallel, as the capacities of the battery cells may be too different. Therefore, the battery packs supplied by us have been specially selected.

Special Instructions for Charging LiPo Batteries

To charge LiPo batteries, use only approved chargers with their associated charging cables. Any operation on the charger or charging cable can have serious consequences. When using a charging cable with a protection circuit, a mandatory and complete control over each individual element of the battery pack is carried out. The maximum charging capacity should be limited to 1.05 times the battery capacity.

P Example: For a 1800 mAh battery: The charging capacity is 1890 mAh.

To charge and discharge a LiPo battery, use only chargers and dischargers that are specifically designed to work with this type of battery. Make sure the correct number of cells is set, as well as the correct charge end voltage and discharge end voltage. When doing this, follow the instruction manual for your charger/discharger.

Additional Handling Instructions

The battery to be charged must be placed on a non-breakable, heat-resistant, non-conductive support during the charging process! Flammable and flammable items should also be kept away from the charging area.

LiPo batteries connected in series can only be charged together in a block if the voltage of the individual cells deviates by no more than 0.05 V. If the voltage deviation is more than 0.05 V, then the voltage should be equalized as accurately as possible by charging or discharging each battery cell.

Under these conditions, a LiPo battery can be charged with a maximum of 1C (the value of 1C corresponds to the capacity of one cell) of the charging current. Starting from max. voltage of 4.2 V per cell, you should continue charging at a constant voltage of 4.2 V until the charging current is less than 0.1-0.2 A.

Voltages above 4.25 V per cell should be avoided as otherwise it may be permanently damaged. To prevent overcharging, you should set the charge off value to 4.1-4.5V per cell, which will increase battery life.

After each charging process, it should be checked whether the permissible voltage of 4.2 V of individual cells is exceeded. Should be the same voltage. If the voltage of individual battery cells deviates by more than 0.05 V, then the voltage should be equalized by charging or discharging each cell individually. To prevent overcharging, after using the unit for a long time, they should be charged individually on a regular basis.

Always observe the correct polarity when charging the battery. If the polarity is reversed during charging, abnormal chemical reactions occur and the battery becomes unusable. This may result in cracking, smoke or fire. The allowable temperature range for charging and storing LiPo batteries is 0-50°C.

Storage: LiPo batteries should be stored charged at 20% of their nominal capacity. If the voltage of the battery cells drops below 3 V, then they must be recharged. Deep discharge and storage in a discharged state (cell voltage less than 3 V) make the battery unusable.

Special instructions for discharging a LiPo battery:

Discharging below 3 volts per cell causes permanent damage to them, so this situation must be avoided. If the individual cells differ in charge level, then the regulator shutdown due to low voltage will occur too late, as a result of which the individual cells may be too discharged.

The battery temperature during discharging should not rise above 70°C. Otherwise, you should take care of better cooling or reduce the discharge current.

battery shell

Film-laminated aluminum foil can be easily damaged by sharp objects such as needles, knives, nails, motor contacts, etc. Due to damage to the film, the battery becomes unusable. Therefore, the battery should be inserted into the model in such a way that the battery cannot be deformed even if the model falls or collides with other objects. If the battery is shorted, it may catch fire.

Temperatures above 70°C can also damage the case, making it leaky. This leads to the loss of electrolyte, the battery becomes unusable and must be disposed of.

mechanical shock

LiPo batteries do not have the same mechanical stability as batteries in metal cases. Therefore, avoid mechanical shocks that may be caused by falling, bumping, bending, etc. Never cut, tear, deform, or drill into the laminated aluminum foil, or bend or bend the LiPo battery. Do not put pressure on the battery or contacts.

Contact handling:

Contacts are not as strong as in other batteries. This applies especially to the aluminum positive contact. Contacts break off easily. Due to heat transfer, the outer terminals of the contacts must not be soldered directly.

Cell connection

Direct soldering of battery cells to each other is not allowed.

When soldering directly, high temperatures can damage battery components such as the separator or insulator. Connections to the battery may only be made industrially by means of spot welding. If the cable is missing or broken, professional repair is required by the manufacturer or distributor.

General Precautions When Using Batteries

Do not expose batteries to fire or incinerate them.

Keep water and other liquids away from the elements.

Do not overheat the elements. With strong heating (over 90 ° C), the insulator may melt, the structure of the element. This may result in significant heat generation, fire or explosion.

Batteries must not be exposed to microwaves or pressure. This can cause smoke, fire and more serious consequences.

Batteries should be stored and charged on a stand made of non-flammable, heat-resistant and non-conductive materials.

Observe the polarity when connecting the elements to the charger or consumer. Reverse polarity charging may cause fire or explosion.

Do not short-circuit cell or battery leads. Large short circuit currents inevitably lead to the release of a significant amount of heat, loss of electrolyte, gas formation, fire or explosion.

Protect the elements from shock and damage, do not drop them. Strong mechanical influences can disrupt the internal structure. Deformations can cause a short circuit, which can lead to significant heat generation, fire or explosion.

Be careful when soldering elements. Overheating of the terminals may cause the battery jacket to melt, which may result in significant heat generation, fire, or explosion.

Do not disassemble or modify the elements. Disassembling the battery can cause internal short circuits. This can result in gas, fire, explosions or other problems.

After use, disconnect the battery from the consumer to avoid deep discharge.

Keep away from children. If the battery is swallowed, contact a doctor or an ambulance immediately. Incorrect use is dangerous.

When charging batteries

Do not use chargers not approved by the manufacturer. Follow the charging modes recommended by the cell manufacturer. Failure to comply with the specified modes (temperature, voltage or current, incorrect functioning of the shutdown devices) can lead to the release of a significant amount of heat, fire or explosion.

Carry out charging under constant supervision. Never leave rechargeable batteries unattended.

Do not connect the battery directly to a power source (accumulator, power supply, etc.). High voltage causes excessive charging current, which can lead to significant heat generation, fire or explosion.

After the charging time specified by the manufacturer, stop the charging process, even if it is not completed.

The batteries built into the device must be removed from the device if they are not currently in use, unused devices must be turned off in a timely manner to prevent deep discharges. Keep the batteries charged in a timely manner. Deeply discharged LiPo batteries are defective and should not be used again.

Do not charge the battery near heat sources or in a car. Overheating may cause electrolyte leakage, excessive heat generation, fire or explosion.

Do not use or charge Lithium Polymer cells with dry cells or batteries of any other type or capacity. In such cases, a deep discharge or an overcharge of the cells is likely. These factors cause undesirable chemical reactions in the elements, which can lead to the release of a significant amount of heat, fire or explosion.

If you notice a change in the shape, color of the element, an unfamiliar smell, or if you find the element heating, immediately disconnect it from the consumer or charger and avoid using this element in the future.

If the cell seal is compromised (case integrity damage, electrolyte leakage, or odor found), immediately remove the cell from any source of open flame. The electrolyte is flammable.

The electrolytes contained in LiPo batteries or electrolyte vapors are harmful to health. Never allow direct contact with electrolytes.

If electrolyte comes into contact with the skin, eyes, or other parts of the body, wash immediately with plenty of clean water, then seek medical attention. If help is not provided in a timely manner, prolonged exposure to the electrolyte can cause serious harm.

Batteries that are damaged or worn out are classified as special waste and must be disposed of properly.

Airsoft guns

There have been a lot of questions about LiPo batteries lately. I decided to write an article about charging, using and selecting LiPo batteries.

For example, consider the battery ZIPPY Flightmax 1000mAh 2S1P 20C

Anything up to 1000 is the manufacturer's name or trademark.

1000mAh is the capacity of the battery.

2S1P– 2S is the number of batteries in the assembly. Each battery has a voltage of about 3.7 volts, so the voltage of such a battery is 7.4 volts. 1P is the number of builds. That is, if you take 2 identical batteries, connect them with electrical tape and solder the power wires in parallel (plus with plus, and minus with minus), then we will get a doubling of the capacity, such a battery is designated 1000 2S2P and actually equals 2000 2S1P in operation. Usually only single assemblies are used, so 1P is not spoken or written.

20C- the maximum discharge current, measured in battery capacities.

To calculate how many LiPo can deliver amps when loaded with an engine, you need to multiply the Capacitance by the number of C and divide by 1000 (since the capacitance is indicated in milliamps / hours). The maximum current of this battery will be 20 amps. For 2200 20С - 44 amperes, 1200 30С = 36 amperes and so on.

Charging LiPo batteries

LiPo batteries are charged at 1C (unless otherwise indicated on the battery itself, they have recently appeared with the ability to charge with a current of 2 and 5C). The standard charging current of the battery in question is 1 Amp. For a 2200 battery, it will be 2.2 amps, and so on.

The computerized charger balances the battery (equalizing the voltage on each cell of the battery) during charging. Although it is possible to charge 2S batteries without connecting a balance cable (white connector in the photo), I highly recommend always connect the balancing plug! 3S and large assemblies only charge with the balance wire connected! If you don't connect and one of the cans draws more than 4.4 volts, then an unforgettable fireworks display awaits you!

You can protect yourself and charge in special packages - they are non-combustible and are specifically designed to reduce harm in the event of a LiPo battery fire.

We continue the story about charging LiPo batteries.

Usually, about 90% of the capacity is quickly poured into the battery, and then recharging begins with balancing the cans. More charged and approached the limit are shunted and the charge goes to the remaining banks. That is why it can charge a pair of 3S batteries as one 6S.

The battery charges to 4.2 volts per cell (usually a few millivolts less).

Storage mode

On a “smart” charger, you can put LiPo into storage mode, while the battery will recharge / recharge up to 3.85V per cell. Fully charged batteries will die if stored for more than 2 months (maybe less). Verified by personal experience. They say that they are completely discharged too, but for a longer period.

I store batteries in a plastic case. It's comfortable. A friend keeps and wears in the field in the aforementioned packages. LiPo is an ordinary battery and if you do not close the contacts and do not break through it, then it will not bring any trouble during storage and transportation.

Operation LiPo

Discharging a LiPo battery below 3 volts per cell is not recommended - it can die. You can use sound indicators, but there is a chance that it will squeak at the most inopportune moment and you will be bombarded with balls from head to toe, like the last losharu! The sound buzzer is connected to the balancing connector and when it squeaks, it's time to change or take out the secondary.

When the motor draws more current than the battery can supply, LiPo tends to swell and die. So this must be strictly monitored! Use wattmeters for control.

During operation, there is one more nuance - our battery is 1000mAh 20C. The idea is to give 20A. Motors usually allow you to exceed the recommended currents by 20%, however, I exceeded by 80% 🙂

In reality, the batteries do not hold the maximum current output very well. For example, my 2200 20C gives a current of 44A in just 2-3 minutes, then there is a voltage drop, although according to calculations it is obliged to give at least 5 minutes.

So when choosing a LiPo battery, we look at the maximum current declared for the selected engine and add a reserve. So for a motor that eats 8-12A, our 1000mAh 20C is quite suitable, but for 16-18A I would choose either with a higher current output, for example 25-30C, or take a larger capacity, for example 1600 20C.

At the time of my active hobby for radio-controlled things, I used Turnigy 9x radio equipment, which I powered through a lithium-polymer battery with a low discharge current - unlike model batteries, which give out tens of amperes of current, low-discharge ones are used to power all sorts of low-power things.

In general, once I simply forgot to turn off the remote control and during the night the battery landed to an unacceptable voltage level:

A voltage of 3.63 volts is very, VERY low. For example, a similar model battery - it also consists of three consecutive "cans" - produces quite the correct voltage:

It would seem, what is the problem? We connect the battery to the charger and just charge. But all smart chargers are called “smart” for a reason: they simply refuse to charge deeply discharged batteries and display a “Low voltage” error:

But why-u-u-u-u-u?! Lay-lu-la-ah-ah...

The voltage of a lithium polymer battery is no joke!

Let's start with stress. There are three of them.

1. 4.2V- This top voltage on a fully charged bank (cell). For two cans - 8.4V. For three - 12.6V and beyond. When the upper voltage is reached, the charging process stops. You can’t go any higher - supercharged batteries bang and explode provocatively and with a spark, this is VERY dangerous and cannot be extinguished with water.
2. 3.7V- This Rated voltage at the bank. It is indicated on the battery. For two cans - 7.4V. For three - 11.1V and beyond. Remember that this is not the full charge voltage, but rather the average.
3. 3.0V- This minimum voltage at the bank. Someone takes the lower limit for 3.2V, but three volts per cell is generally a super minimum. You can't go below. Below will be bad. In my case, 3.6V for three banks is 1.2V for each, that is, much less than the superminimum limit.

Deep discharge is very, VERY bad.

There is a magical chemistry in the battery that allows it to be discharged and recharged again. A deep discharge breaks this chemistry and after a discharge, the battery either cannot be charged back at all, or it is impossible to charge back several specific cells, or it is impossible to reach its former capacity ... In general, there will be something “not right”. And what exactly will be - it is necessary to find out in each case. Therefore, it is necessary to charge a deeply discharged battery and find out everything.

And how to do this if the charger refuses flatly? Let's cheat.

Charging a deeply discharged battery with a smart charger

In an intelligent (adjustable) charger, the battery is connected twice: with a power connector (plus or minus) and balanced (the number of contacts depends on the number of cans). Through the power one, life is poured into the battery, and through the balanced one, the uniformity of the bay in each jar is controlled.

To fool the intellect of the charger, we connect the affected battery to the power connector, and the working one to the balanced one. And everything will be fine, but remember the important points.

1. Measure the voltage on each cell with a multimeter. Mentally number the pins of the balanced connector (for example, 1-2-3-4 for a three-jar) and check the voltage on each pair of pins (in my case 1-2, 2-3, 3-4). Write this data somewhere.
2. To cheat, you must use the SAME battery configuration. If the three-jar (3S) is affected, then use 3S to cheat too.
3. Set the minimum charge current, no more than 0.5A. I know, the standard charge current for my model battery is 5A, for the victim - 2.6A. But here you have to be patient and wait - safety is above all!
4. Regularly check the voltage with a multimeter on each bank during the charge process (as in step 1) - it should not be higher than 4.2V.
5. Stop the fake charging process when each cell reaches 3.0-3.2V. From now on, you can charge the battery as usual.

I have already said that after charging there may be “something not right”. Some bank may not accept a charge from you - you will calculate this by the fact that the voltage on it will not rise during the charge process. It was like that for me: the first two charged normally, and the third did not want to in any way. So the battery had to be disposed of, unfortunately. But if you don't have such a deep discharge, then you may be able to bring the battery back to life completely. Perhaps it will be discharged faster than before. But it's better than nothing.

These batteries rightfully deserve such reviews as "the most fastidious, dangerous, unreliable and short-lived", but despite all these shortcomings, the use of these batteries is growing rapidly, as they have an unsurpassed indicator of specific (per mass) energy, and are also capable of delivering large discharge currents. So for power electric motors, there is practically no alternative to these batteries yet.

We briefly list the basic rules for operating LiPo batteries, giving below detailed explanations of the reasons for those interested:

1.When charging LiPos, only charge them with a dedicated LiPo charger and only under supervision. In the event of any internal damage during charging, spontaneous combustion and fire may occur.

2.Never charge the battery without a balancer - a device that controls and equalizes the voltage on each "bank" in a series-connected battery. For devices like iMax B6, G.T.Power A6 and the like that have a built-in balancer and a choice of charge methods, always select Balance Charge mode instead of just LiPo Charge. The latter does not balance or control each of the cans.

3. For charging, use a current of no more than 1C if you are in the field, and about 0.5-0.7C at home. According to some reports, a slower charge will extend the life of the battery. Addendum: Some newer battery types like the Hyperion G3 allow charging currents up to 5C. In this case, such a charge can be recommended in the field, and at home - 2-3C will be enough, although 1C at home will not make it worse.

4.Never allow the battery to be deeply discharged, as She is irreversibly disabled.

5. If possible, do not bring the battery to full discharge - it is better to leave 10-20% of the capacity in it and charge it again than to kill it all at once.

6. If possible, try to use batteries with some margin for rated current. This will extend their service life. As mentioned above, LiPo batteries are very critical to the mode of operation. When charging them, the CC-CV method is used. That is, initially the battery is charged with some fixed current (CC), while the voltage on the battery banks increases. Upon reaching the voltage of 4.20 volts on each bank, the battery is already charged to about 95%, and the charger proceeds to the second phase of the CV charge algorithm (constant voltage, constant voltage). In this case, the current is gradually reduced so that the voltage on each bank does not exceed 4.20 volts. This value is determined by the chemistry of the LiPo battery. Exceeding it is permissible no more than up to 4.25 volts, and reaching a value of 4.30 and above is fraught with explosive spontaneous combustion.

The CV charge phase in the field is negligible: it adds only the last 5% of the capacity, but takes about a third to a half of the total charge time at a 1C charge. Therefore, you can stop charging when the battery reaches the maximum voltage value, saving time.

When discharging during operation, it is unacceptable to reduce the voltage on each of the cans below 3 volts. It is enough to put a LiPo battery up to 2.5 volts per jar once, and, as a rule, it can be thrown away. After such a discharge, the battery may "swell", it loses more than half of its capacity and ceases to give the rated discharge current. For some time, the battery loses its capacity, almost completely.

Hence the problem of operating LiPo is that during charging it is necessary to control the voltage on each of the cans so as not to disable it, and during the subsequent discharge, all the banks were discharged equally, but not below the permissible minimum. A conventional charger can control the voltage on the battery as a whole, but with a large spread of voltages on the banks, it is quite possible that one of them has another 4.05 volts, and the second has 4.30. Charging sees only a total of 8.35 and continues to charge the battery up to 8.40 (4.20 * 2). In this case, the voltage on the second bank exceeds 4.30, which most likely leads to a fire. When discharging an unbalanced battery, the same problem can overdischarge a single cell, despite the fact that the total voltage is even higher than 3 volts * number of cells.

To solve this problem, a special device called a balancer is used. In the process of charging, it monitors the voltage on each of the cans and aligns them with each other. In this case, the charger will turn off the charge in time, without damaging the battery. When a balanced battery is discharged on a model, all banks are also discharged more or less evenly, and when the total voltage drops to 3 volts per bank, the regulator cut-off should work, which will prevent the battery from failing. Many modern chargers already have a built-in balancer, which you should definitely use by connecting a separate battery balancing connector along with the power one and choosing the appropriate charge mode. For devices that do not have a built-in balancer, you must purchase a separate external device.

The LiPo charge current must not exceed the battery capacity, i.e. the maximum charge current is 1C. For example, to charge a battery with a capacity of 2200 mAh, the charge current should not exceed 2.2 A. At the same time, the charge current should not be set less than 0.5C. Some chargers (Duratrax ICE) have a non-switchable timer to charge LiPo batteries for 3 hours. By setting a small current, the charger may not fully charge the battery, but turn off by a timer. There are chargers that have this timer adjustable, but it doesn't make much sense to use it for LiPo charging.

There is no point in forcibly discharging or cycling a lithium battery, since these batteries have no memory effect and must be stored in a charged state (the most optimal storage mode is 60% charge). The battery discharge current can be any, but not more than its nominal value indicated on the label, also in units of capacity C. For example, 20C on a 1000 mAh battery means that the maximum continuous discharge current is 20 * 1000 = 20000 mA = 20 A. It should be noted that that if you do not use the battery to the limit of its capabilities, then it will live a much larger number of cycles. For example, for one of the branded expensive LiPos with a rated current of 30C, the following typical data are given: when charging and discharging with currents of 1C, the manufacturer guarantees 500 cycles without significant loss of capacity. When charging with a current of 1C, but discharging with a maximum allowable current of 30C, the number of cycles will be only 50 (it will drop 10 times). This gives a good example of why it is desirable to have a battery current headroom.

In the process of charging or discharging, do not allow the battery to heat up more than 60 degrees. The place where the battery is installed on the model must be well ventilated and even ventilated. Do not wrap the battery with heat-insulating materials (foam rubber, polystyrene). If the battery does become warm, allow it to cool before using (charging or discharging).

Example of charging LiPo GE 2200 25C 22V

As an illustration of what has been said below, a typical graph of the charge of a lithium-polymer assembly of two series-connected GE 2200 25C 11.1V batteries after use is shown. The graph was obtained using an Infinity 960SR charger with an external LCB12s balancer connected to a computer.

The red line shows the charge current, the blue line shows the voltage on the battery, the colored lines show 6 voltage graphs on each of the cans of the resulting assembly.

The graph shows the following:

1. Initially, the current is set to 0.5C (1.1A), and this current charges the battery to approximately 95% of its capacity (DC phase, CC). In this case, the voltage on the battery gradually increases from about 19.8 volts to 25.2.

2. The current dip at the 10th minute of charging is caused by the charger measuring the internal resistance of the battery (an important parameter for assessing the condition of the battery).

3. After the battery reached its maximum voltage (4.2 volts per cell or 25.2 for the entire battery), the current began to decrease, and the voltage became constant (constant voltage phase, CV).

4. It is clearly seen that at the first 10% of the capacity, the voltage spread of the cans is maximum. This is one of the reasons why it is not recommended to discharge the battery by 100% - it is in the last 10% that a rapid drop in voltage occurs on banks with a large spread, and it is at this moment that the battery can be damaged.

5. It can be seen that in the first 10 minutes of the charge, the balancer almost completely equalized the voltages on the banks. Current fluctuations at the 50th minute are caused by a small spread in the parameters of the cans - again the work for the balancer, which inevitably affects the charge current supported by the device.

6. The charge is performed until the current drops to a value equal to 1/10 of the initial one. A gentle charge mode was set with a current of 1.1A, and the shutdown occurred when the current dropped below 0.11A. The values ​​of the capacity, current and voltage obtained by the battery at the end of the charge are displayed numerically. From the graph, we can conclude that a particular battery has the declared capacity (in this case, at a nominal value of 2200 mAh, it received 2190 mAh after operation. In addition, the balance of the battery cans is almost perfect, which directly indicates the quality of this brand and a particular battery, in particular.