Charge the li ion battery for the first time. Features of lithium-ion batteries. How to properly charge lithium-ion batteries

Lithium batteries are a galvanic pair in which lithium salts serve as the cathode. Independently, lithium-ion, lithium polymer dry cell or hybrid battery, Charger suits everyone. Products can be in the form of a cylinder, or hermetically sealed soft packaging, the charging method for them is general, corresponding to the peculiarities of the electrochemical reaction. How to charge a Li-ion battery?

There are several schemes for charging lithium batteries. The two-stage charging developed by SONY is more commonly used. Devices with pulse charging and step charging, as for acid batteries, are not used.

Charging any type of lithium ion or lithium polymer battery requires strict voltage compliance. One cell of a charged lithium battery should have no more than 4.2 V. The nominal voltage for them is 3.7 V.

Lithium batteries can be charged quickly, not fully? Yes. You can always recharge them. Battery operation by 40-80% capacity lengthens the battery shelf life.

Lithium battery two-stage charging circuit

CC / CV circuit principle - constant charging current / constant voltage. How to charge a lithium battery using this scheme?

The diagram before stage 1 of charging shows a pre-stage for restoring a deeply seated lithium battery, with a voltage at the terminals of at least 2.0 V. The first stage should restore 70-80% of the capacity. The charging current is chosen 0.2-0.5 C. You can accelerate charging, with a current of 0.5-1.0 C. (C is the capacity of lithium batteries, digital value). What should be the charging voltage at the first stage? Stable, 5 V. When the voltage at the battery terminals 4.2 is reached, this is a signal to go to the second stage.

Now the charger maintains a stable voltage at the terminals, and the charging current decreases as the capacity rises. When its value decreases to 0.05-0.01 C, charging will end, the device will turn off, preventing overcharging. The total recovery time for a lithium battery does not exceed 3 hours.

If the lithium-ion battery is discharged deeper than 3.0V, a "jolt" will be required. This consists in charging with low current until the terminals are 3.1 V. Then the usual circuit is used.

How charging parameters are controlled

Since lithium batteries operate in a narrow range of voltage variation at the terminals, they cannot be recharged above 4.2 V and discharged below 3 V. The charge controller is installed in the charger. But each battery or battery has its own breakers, PCB board or PCM protection modules. In the batteries, it is precisely the protection against one factor or another that is installed. In case of violation of the parameter, it must turn off the bank, break the circuit.

A controller is a device that must implement control functions - switch CC / CV modes, control the amount of energy in banks, turn off charging. In this case, the assembly works, heats up.

Homemade charging circuits used for lithium batteries

LM317 is a simple charger circuit with a charge indicator. From USB port not powered.
MAX1555, MAX1551- special for Li Batteries, install in phone to USB power adapter. There is a precharge function.
LP2951- stabilizer limits the current, forms a stable voltage of 4.08-4.26V.
MCP73831 is one of the simplest circuits, suitable for charging ionic and polymer devices.

If the battery consists of several cells, they are not always discharged evenly. When charging, you need a balancer that distributes the charge and ensures that all the cells in the battery are charged evenly. The balancer can be separate or built into the battery connection diagram. The battery protection device is called BMS. Knowing how to charge devices, understanding the circuits, you can do it yourself with a circuit of a protective device for a lithium battery.

How to charge a 12 volt lithium battery

Each lithium battery is a sealed product of a cylindrical, prismatic shape, for Li-pol in a soft package. They all have a voltage of 3.6-4.2 V and a different capacitance, measured in mA / h. If you collect 3 cans in series, you get a battery with a voltage at the terminals of 10.8 - 12.6 V. The capacity during sequential charging is measured by the weakest lithium battery in the bundle.

How to properly charge a 12 volt lithium 18650 or Pol battery, you need to know. To return the container to the device, it is necessary to use a charger with a controller. It is important to have in the PCM assembly for each can, protection against under- and overcharging. Another scheme of unprotected lithium-ion batteries is the installation of a PCB - a control board, preferably with balancers, for uniform charging of the cans.

On the charger, you must set the voltage under which the battery operates, 12.6 V. The number of cans and the charging current are set on the dashboard, equal to 0.2-0.5 C.

How to charge, we suggest watching a video, charging method for 2, 3 lithium 18650 batteries connected in series. A budget charger is used.

Charging options for lithium-ion lithium polymer batteries:

Charger purchased with the device.
Use a USB connector from electronic equipment - computer. Here you can get a current of 0.5 A, charging will take a long time.
From the cigarette lighter by purchasing an adapter with a set of ports. Choose the one that matches the 12 V battery specifications.
Universal charger "frog" with a dock for installing a gadget. How to charge? There is a charge indication panel.

Experts advise using a standard charger to charge lithium batteries, the rest - only in force majeure circumstances. However, you need to know how to charge a lithium battery without a standard charger.

How to charge a screwdriver lithium battery

A lithium battery screwdriver is almost always an upgrade. Whereas Ni-Cd cells had the same charging requirements, they are now the opposite. First of all, you need to purchase or assemble a charger, specifically for the power-hungry lithium batteries of a screwdriver with a form factor 18650. The charging scheme is used in two stages CC / CV.

Charging the lithium battery of a screwdriver is optimal when 20-50% of the capacity remains - one stick on the indicator. The more often you charge, the more stable the voltage at the terminals and the longer the life of the energy source. The more even the voltage at the terminals, the more cycles the screwdriver's lithium battery will withstand.

If there are 2 batteries in the screwdriver, remove one, charge to 50-60% and keep in reserve. But always charge the second one at the end of work, even by 10%. The best temperature for charging is + 15-25 0 C. At minus, the battery of the screwdriver will not charge, but it can work up to -10 0.

How to charge the lithium battery of a screwdriver with a charger depends on the scheme for collecting the battery from the cans. In any case, the voltage on the charger should be equal to that declared for the device, and the current strength should be 0.5 C at the first stage. On the second, the terminal voltage is stable, and the current falls, until the end of the process.

How much to charge the lithium battery

The charging time of the batteries is determined by the process of restoring the capacity. Distinguish between full and partial charges.

Capacity is measured in ampere-hours. This means, if you apply a charge that is numerically equal to the capacity, then in an hour the required voltage will be created at the terminals, and the energy reserve will be 70-80%. If capacitance is measured in C units, 1C-2C current should be applied during fast charging. Fast charging time is about an hour.

For a complete charging cycle of batteries from several cells connected in series, 2 stages are used - CC / CV. The SS stage lasts until a voltage equal to the operating voltage appears at the terminals, in volts. The second stage: at a stable voltage, a current is supplied to the jar, but with an increase in capacity, it tends to zero. Charging time takes about 3 hours, regardless of capacity.

Is it possible to charge a lithium battery with regular charging

Two different systems batteries - lithium and lead-acid require different approach to restore capacity. Lead-acid batteries are not as demanding on charging parameters as lithium ones. And the charge criteria are different.

For charging in the first stage, Li-ion, Li-pol requires constant current, in the second stage, constant voltage. If you do not control the parameters at the first stage, overcharging is possible. But if the battery has built-in protection - BMS - it can handle it. Therefore, you can even add some energy with a phone charger.

In a charger for lead-acid batteries, the main indicator is a stable voltage. For lithium chargers, a stable current is important in the first stage.

True, there are universal chargers that can be reconfigured to one or another charging mode. Here is the Russian development "Kulon".

Batteries

How to charge a li ion 18650 battery? How to properly operate such a battery. What are lithium-ion power supplies to be afraid of and how can such a battery extend its service life? Similar questions can arise in a wide variety of electronics industries.

And if you decide to assemble your first flashlight or electronic cigarette with your own hands, then you definitely need to familiarize yourself with the rules for working with such power sources.

Lithium- ion battery Is a type of electric current accumulator, which since 1991, after being presented to the market by SONY, has become widespread in modern household and electronic equipment. Such batteries are used as a power source in cell phones, laptops and camcorders as a power source for electronic cigarettes and electric vehicles.

The disadvantages of this type of battery start with the fact that the first generation lithium ion batteries were the explosion in the market. Not only literally, but also figuratively. These batteries exploded.

This was explained by the fact that a lithium metal anode was used inside. In the process of numerous charges and discharges of such a battery, spatial formations appeared at the anode, which led to the closure of the electrodes, and as a result, to a fire or explosion.

After this material was replaced with graphite, this problem was eliminated, but there could still be problems on the cathode, which was made of cobalt oxide. If the operating conditions were violated, or rather overcharging, the problem could recur. This was corrected with the beginning of the use of lithium-ferro-phosphate batteries.

All modern lithium-ion batteries prevent overheating and overcharging, but the problem of loss of charge at low temperatures remains.

Among the indisputable advantages of lithium-ion batteries, I would like to note the following:

high battery capacity;
low self-discharge;
no need for maintenance.

Original chargers

The charger for lithium-ion batteries is quite similar to the charger for lead acid batteries. The only difference is that the lithium-ion battery has very high voltages per cell and tighter voltage tolerance requirements.

Such a battery is called a can because of the external similarity with aluminum cans for drinks. The most common battery of this form is the 18650. The battery received this designation due to its dimensions: 18 millimeters in diameter and 65 millimeters in height.

While some inaccuracies in indicating the boundary voltages during charging are permissible for lead-acid batteries, the situation with lithium-ion cells is much more specific. During charging, when the voltage rises to 4.2 Volts, the voltage supply to the cell should stop. The margin of error is only 0.05 volts.

Chinese chargers that can be found on the market can rely on batteries based on different materials. Li-ion, without prejudice to its performance, can be charged with a current of 0.8 A. In this case, you need to very carefully monitor the voltage on the bank. It is advisable not to allow values above 4.2 Volts. If there is a controller in the assembly with the battery, then there is nothing to worry about, the controller will do everything for you.

The most ideal charger for lithium-ion batteries is a voltage regulator and current limiting device at the beginning of the charge.

Lithium needs to be charged with a stable voltage and current limiting at the beginning of the charge.

Homemade charger

To charge the 18650, you can buy a universal charger, and not be tormented by the question of how to check the necessary parameters with a multimeter. But such an acquisition will cost you a pretty penny.

The price for such a device will vary around $ 45. But you can still spend 2-3 hours and assemble the charger with your own hands. Moreover, this charger will be cheap, reliable and will automatically disconnect your battery.

The parts that we will use today to create our charger are available to every radio amateur. If a radio amateur with the necessary parts is not at hand, then on the radio market you can buy all the parts for no more than 2-4 dollars. The circuit, which is assembled correctly and neatly assembled, starts working immediately and does not need any additional debugging.

18650 battery charging circuit.

On top of that, by installing the stabilizer on a suitable radiator, you can safely charge your batteries without fear of overheating and catching fire. The same cannot be said about Chinese chargers.

The circuit works quite simply. First, the battery needs to be charged with constant current, which is determined by the resistance of the resistor R4. After the battery has a voltage of 4.2 Volts, charging begins constant voltage... When the charging current drops to very low values, the LED in the circuit will turn off.

The currents recommended for charging lithium-ion batteries should not exceed 10% of the battery capacity. This will extend the life of your battery. When the value of the resistor R4 is 11 Ohm, the current in the circuit will be 100 mA. If you use a 5 ohm resistance, then the charging current will already be 230 mA.

How to extend the life of your 18650

Disassembled battery.

If you have to leave your lithium-ion battery without work for a while, it is better to store the batteries separately from the device that they power. A fully charged cell will lose part of its charge over time.

An element that is very little charged, or discharged at all, can permanently lose its performance after a long hibernation. Storing the 18650 at a charge level of about 50 percent is optimal.

Do not allow the cell to be completely discharged and overcharged. Lithium-ion batteries have no memory effect at all. It is advisable to charge such batteries until the moment when their charge is completely dry. This can also prolong the battery life.

Lithium Ions do not like heat or cold. The optimal temperature conditions for these batteries will be in the range from +10 to +25 degrees Celsius.

Cold can not only reduce the operating time of an element, but also destroy its chemical system. I think each of us noticed how the charge level in a mobile phone quickly drops in the cold.

Conclusion

Summarizing all of the above, I would like to note that if you are going to charge a lithium-ion battery using a store-made charger, pay attention to the fact that it is not made in China. Very often, these chargers are assembled from cheap materials and are not always respected in them required technology which can lead to undesirable consequences in the form of fires.

If you want to assemble the device yourself, then you need to charge the lithium-ion battery with a current that will be 10% of the battery capacity. The maximum may be a figure of 20 percent, but this figure is already undesirable.

When using such batteries, it is worth following the rules of operation and storage in order to exclude the possibility of an explosion, for example, from overheating, or failure.

Compliance with the conditions and rules of operation will extend the life of the lithium-ion battery, and as a result - save you unnecessary financial costs. The battery is your helper. Take care of her!

Lithium batteries (Li-Io, Li-Po) are the most popular on this moment rechargeable sources of electrical energy. The lithium battery has a nominal voltage of 3.7 volts, which is indicated on the case. However, a 100% charged battery has a voltage of 4.2 V, and a discharged “to zero” - 2.5 V, there is no point in discharging the battery below 3 V, firstly, it deteriorates from this, and secondly, in the range from 3 to 2.5 Only a couple of percent of the energy is transferred to the battery. Thus, the operating voltage range is taken to be 3 - 4.2 Volts. You can watch my selection of tips for using and storing lithium batteries in this video.

There are two options for connecting batteries, serial and parallel.

With a series connection, the voltage on all batteries is summed up, when the load is connected, a current equal to the total current in the circuit flows from each battery, in general, the load resistance sets the discharge current. You must remember this from school. Now comes the fun part, the capacity. The capacity of the assembly with such a connection is good equal to the capacity of the battery with the smallest capacity. Let's assume that all batteries are 100% charged. Look, the discharge current is the same everywhere, and the battery with the smallest capacity will be discharged first, this is at least logical. And as soon as it is discharged, it will no longer be possible to load this assembly further. Yes, the rest of the batteries are still charged. But if we continue to remove the current, then our weak battery will start to over discharge and fail. That is, it is correct to assume that the capacity of a series-connected assembly is equal to the capacity of the smallest or most discharged battery. From here we conclude: firstly, you need to collect a serial battery from batteries of the same capacity, and secondly, before assembly, they must all be charged the same way, in other words, 100%. There is such a thing called BMS (Battery Monitoring System), it can monitor each battery in the battery, and as soon as one of them is discharged, it disconnects the entire battery from the load, this will be discussed below. Now with regard to charging such a battery. You need to charge it with a voltage equal to the sum of the maximum voltages on all batteries. For lithium, this is 4.2 volts. That is, we charge a battery of three with a voltage of 12.6 V. See what happens if the batteries are not the same. The battery with the smallest capacity will charge the fastest. But the rest are still not charged. And our poor battery will fry and recharge until the rest are charged. Overdischarge, I remind you, lithium also does not like very much and deteriorates. To avoid this, we recall the previous conclusion.

Let's move on to parallel connection. The capacity of such a battery is equal to the sum of the capacities of all the batteries included in it. The discharge current for each cell is equal to the total load current divided by the number of cells. That is, the more Akum in such an assembly, the more current it can deliver. An interesting thing happens with tension. If we collect batteries that have different voltages, that is, roughly speaking, charged to different percentages, then after connection they will begin to exchange energy until the voltage on all cells becomes the same. We conclude: before assembling the Akum, they must again be charged in the same way, otherwise, when connected, large currents will flow, and the discharged Akum will be damaged, and most likely it may even catch fire. In the process of discharging, the batteries also exchange energy, that is, if one of the cans has a lower capacity, the rest will not allow it to discharge faster than themselves, that is, batteries with different capacities can be used in parallel assembly. The only exception is work at high currents. On the different batteries under load, the voltage sags in different ways, and between the “strong” and “weak” Akum, the current will start to run, but we do not need this at all. And the same goes for charging. You can absolutely safely charge batteries of different capacities in parallel, that is, balancing is not needed, the assembly will balance itself.

In both cases considered, the charging current and the discharge current must be observed. The charging current for Li-Io should not exceed half the battery capacity in amperes (1000 mah battery - charge 0.5 A, battery 2 Ah, charge 1 A). The maximum discharge current is usually indicated in the datasheet (TTX) of the battery. For example: laptop 18650s and batteries from smartphones cannot be loaded with a current exceeding 2 battery capacities in Amperes (example: Akum for 2500 mah, which means that you need to take a maximum of 2.5 * 2 = 5 Amperes from it). But there are high-current batteries, where the discharge current is clearly indicated in the characteristics.

Features of charging batteries with Chinese modules

Standard commercially available charging and protection module for 20 rubles for lithium battery ( link to Aliexpress)
(positioned by the seller as a module for one 18650 cell) can and will charge any lithium battery regardless of shape, size and capacity to the correct voltage of 4.2 volts (voltage of a fully charged battery, to the eyeballs). Even if it's a huge 8000mah lithium package (of course, we are talking about one 3.6-3.7v cell). The module provides a charging current of 1 amp, this means that they can safely charge any battery with a capacity of 2000mah and above (2Ah, which means the charging current is half the capacity, 1A) and, accordingly, the charging time in hours will be equal to the battery capacity in amperes (in fact, a little more, one and a half to two hours for every 1000mah). By the way, the battery can be connected to the load already during charging.

Important! If you want to charge a battery with a smaller capacity (for example, one old 900mah can or a tiny 230mah lithium bag), then the charging current of 1A is a lot, it should be reduced. This is done by replacing the resistor R3 on the module according to the attached table. The resistor is optional smd, the most common one will do. Let me remind you that the charging current should be half of the battery capacity (or less, no big deal).

But if the seller says that this module is for one 18650 can, can they charge two cans? Or three? What if you need to assemble a capacious power bank from several batteries?
CAN! All lithium batteries can be connected in parallel (all pluses to pluses, all minuses to minuses), REGARDLESS OF CAPACITY. Batteries soldered in parallel maintain an operating voltage of 4.2v and their capacity is added. Even if you take one can at 3400mah and the second at 900, you get 4300. The batteries will work as a whole and will discharge in proportion to their capacity.
The voltage in a PARALLEL assembly is ALWAYS THE SAME ON ALL BATTERIES! And not a single battery can be physically discharged in an assembly earlier than others, the principle of communicating vessels works here. Those who argue the opposite and say that batteries with a lower capacity will discharge faster and die - they confuse it with SEQUENTIAL assembly, spit in their faces.
Important! Before connecting to each other, all batteries must have approximately the same voltage, so that at the moment of soldering, equalizing currents do not flow between them, they can be very large. Therefore, it is best to simply charge each battery separately before assembling. Of course, the charging time of the entire assembly will increase, since you are using the same 1A module. But you can parallelize two modules, getting a charging current of up to 2A (if your charger can give that much). To do this, connect with jumpers all the analogous terminals of the modules (except for Out- and B +, they are duplicated on the boards by other dimes, and will be connected anyway). Or you can buy a module ( link to Aliexpress), on which the microcircuits are already in parallel. This module is capable of charging with a current of 3 Amperes.

Sorry for the obvious, but people are still confused, so we have to discuss the difference between parallel and serial.
PARALLEL the connection (all pluses to pluses, all minuses to minuses) maintains the battery voltage of 4.2 volts, but increases the capacity by adding all the capacities together. All power banks use a parallel connection of several batteries. Such an assembly can still be charged from USB and the voltage rises to the output 5v with a step-up converter.
CONSECUTIVE the connection (each plus to minus of the subsequent battery) gives a multiple increase in the voltage of one charged 4.2v can (2s - 8.4v, 3s - 12.6v, and so on), but the capacity remains the same. If three 2000mah batteries are used, then the assembly capacity is 2000mah.
Important! It is believed that for sequential assembly it is sacred to use only batteries of the same capacity. In fact, this is not the case. You can use different ones, but then the battery capacity will be determined by the LOWEST capacity in the assembly. Add 3000 + 3000 + 800 - you get 800mah assembly. Then the specialists begin to crow, that then the less capacious battery will discharge faster and die. It doesn't matter! The main and truly sacred rule is that for consistent assembly it is always and absolutely necessary to use the BMS protection board for the required number of cans. It will determine the voltage on each cell and turn off the entire assembly if any discharges first. In the case of a bank for 800, it will be discharged, the BMS will disconnect the load from the battery, the discharge will stop and the residual charge of 2200mah on the remaining banks will no longer matter - you need to charge.

The BMS board, in contrast to the single charging module, IS NOT a CHARGER for sequential assembly. To charge you need configured source of the required voltage and current... Guyver made a video about this, so do not waste time, watch it, there it is about it as thoroughly as possible.

Can a daisy chain be charged by connecting multiple single charging modules?
In fact, with some assumptions, it is possible. For some homemade products, the scheme has proven itself using single modules, also connected in series, but EACH module needs its own SEPARATE POWER SUPPLY. If you charge 3s - take three phone chargers and connect each one to one module. When using one source - power short circuit, nothing works. Such a system also works as a protection for the assembly (but the modules are capable of delivering no more than 3 amperes) Or, simply charge the assembly in batches, connecting the module to each battery until it is fully charged.

Battery charge indicator

It is also an urgent problem - at least to know approximately how many percent of the charge remains on the battery so that it does not discharge at the most crucial moment.
For parallel assemblies at 4.2 volts, the most obvious solution would be to immediately purchase a ready-made powerbank board, which already has a display showing the percentage of charge. These percentages are not super-accurate, but they still help. The price of the issue is about 150-200 rubles, all are presented on Guyver's website. Even if you are collecting not a powerbank, but something else, this board is quite cheap and small to place it in a homemade product. Plus, it already has the function of charging and protecting batteries.
There are ready-made miniature indicators for one or several cans, 90-100r
Well, the cheapest and folk method is the use of an MT3608 step-up converter (30 rubles), tuned to 5-5.1v. Actually, if you make a power bank on any 5-volt converter, then you don't even need to buy anything. The revision consists in installing a red or green LED (other colors will work at a different output voltage, from 6V and above) through a 200-500 ohm current-limiting resistor between the output positive terminal (this will be a plus) and the input positive (for the LED it will turn out to be a minus). You are not mistaken, between two pluses! The fact is that when the converter is operating, a voltage difference is created between the pluses, +4.2 and + 5v give each other a voltage of 0.8v. When the battery is discharged, its voltage will drop, and the output from the converter is always stable, which means the difference will increase. And when the voltage on the bank is 3.2-3.4v, the difference will reach the required value to light the LED - it starts to show that it is time to charge.

How to measure the capacity of batteries?

We are already accustomed to the opinion that Aimax b6 is needed for measurement, but it costs money and is redundant for most radio amateurs. But there is a way to measure the capacity of a 1-2-3 can battery with sufficient accuracy and cheap - a simple USB tester.

Lithium-ion batteries are not picky, but for correct work they must be properly looked after. A few simple rules will help you significantly increase battery life. We will determine how to properly charge Li-Ion batteries so that they work for a long time.

A few simple rules for your battery

Use a lithium-ion battery as follows:

carry out a full discharge every three months
the rest of the time, do not fully discharge
keep partially charged
avoid overheating

Now about everything in order

Batteries of this type do not have a memory effect, so the owner can charge them without waiting for a complete discharge. Typically, the manufacturer calculates the service life as a number of discharge cycles. A high-quality battery can easily withstand 500-600 times. If you start charging the battery in a timely manner - more precisely, when its charge rate drops to 10-15 percent, then its service life will approximately double.

But there is an important fact - sometimes it is useful to discharge the battery completely. A full charge during the entire operating time can also cause harm.

Experts advise to discharge the battery completely once a quarter, and then charge it to the maximum and keep it connected to the network for ten hours.

Why are batteries stored charged?

If you are going to store the battery, then the best condition for it will be a charge level of 50 percent. A positive temperature is required, preferably about 20 degrees. If you leave the battery on the shelf for a long time, its capacity will gradually begin to drop. If you put off a completely discharged battery for a long time, then this situation is even worse, there is a high probability that then the device will not even start with it.

How long do batteries hold a charge?

Batteries are discharged very slowly, 5-7 percent of the charge is consumed per month. Manufacturers recommend using only original chargers. Use only quality items, buying fake Chinese ones may negatively affect the condition of the battery.

Features of correct charging

To make the battery last longer, do not start charging it immediately after arriving from frost. High temperature is also a dangerous enemy of such devices, they are not able to endure overheating. This is detrimental to their condition and dangerous to your health, there are often cases when the battery, warmed up under the influence of work and sunlight, caught fire. Samsung Galaxy Note 7 is the most striking example of such devices, a defect in the battery led to the recall and replacement of a larger batch of smartphones. Try to use the battery correctly, so you can significantly extend its life.

At this time, li-ion batteries and Li-pol (lithium polymer) are widely used.

The difference between them lies in the electrolyte. In the first version, helium is used as it, in the second - a polymer saturated with a solution containing lithium. Today, thanks to the popularity of cars powered by electric motors, the question of finding the ideal type of li ion battery, which is optimal for such vehicles, is an acute issue.

It consists, like other batteries, of an anode (porous carbon) and a cathode (lithium), separating them with a separator and a conductor - electrolyte. The discharge process is accompanied by the transfer of "anode" ions to the cathode through the separator and electrolyte. Their direction is reversed during charging (figure below).

Ions circulate in the process of discharging and charging the cell between oppositely charged electrodes.

Ionic batteries have a cathode made of different metals, which is their main difference. Manufacturers use different electrode materials to improve battery performance.

But it happens that the improvement of some characteristics leads to a sharp deterioration in others. For example, by optimizing the capacity required to extend the travel time, you can increase power, safety, and reduce the negative impact on the environment. At the same time, you can reduce the load current, increase the cost or size of the battery.

Get to know the main parameters different types lithium batteries (lithium-manganese, lithium - cobalt, lithium - phosphate and nickel-manganese - cobalt) can be found in the table:

Rules for Users of Electric Vehicles

The capacity of such batteries practically does not decrease during long-term storage. Li ion batteries are discharged by only 23% if stored at 60 degrees for 15 years. It is due to these properties that they are widely used in electric transport technologies.

For electric vehicles, lithium-ion batteries are suitable, which have a full-fledged control system built into the body.

For this reason, during operation, users forget about the basic rules that can extend their service life:

The battery must be fully charged immediately after purchasing it in the store, since the electrodes are charged by 50% during the production process. Therefore, the available capacity will decrease, i.e. operating time if there is no initial charge;
the battery must not be completely discharged in order to preserve its resource;
it is necessary to charge the battery after each trip, even if the charge still remains;
do not heat batteries as high temperatures contribute to the aging process. In order to use the resource as much as possible, it is necessary to operate at the optimum temperature, which is 20-25 degrees. Therefore, the battery cannot be stored near a heat source;
in cold weather, it is recommended to wrap the battery in a plastic bag with a vacuum seal in order to store it at 3-4 degrees, i.e. in a room not heated. The charge must be at least 50% of the full;
after the battery has been operated at negative temperatures, you cannot charge it without keeping it for some time at room temperature, that is, it needs to be warmed up;
you need to charge the battery using the supplied charger.

PU of these batteries are of several subspecies - lithium - LiFePO4 (iron - phosphate), using an iron phosphate cathode. Their characteristics make it possible to speak of batteries as the pinnacle of technologies used for the production of batteries.

Their main advantages are:

the number of charge-discharge cycles, which reaches 5000 until the capacity decreases by 20%;
long service life;
missing "memory effect";
wide temperature range with constant performance (300-700 degrees Celsius);
chemical stability and thermal, which increase safety.

Most commonly used batteries

Among the many, the most common are 18650 li-ion batteries produced by five companies: LG, Sony, Panasonic, Samsung, Sanyo, which have factories in Japan, China, Malaysia and South Korea. It was planned to use 18650 li-ion batteries in laptops. However, thanks to their successful format, they are used in radio-controlled models, electric vehicles, flashlights, etc.

Like any high-quality product, such batteries have a lot of fakes, therefore, in order to extend the life of the device, you only need to purchase batteries of well-known brands.

Protected and unprotected lithium-ion batteries

It is also important for lithium batteries whether they are protected or not. The working range of the former is 4.2-2.5V (used in devices designed to work with lithium-ion sources): LED lamps, low-power household appliances, etc.

Power tools, bicycles with electric motors, notebook computers, video and photographic equipment use unprotected batteries that are controlled by the controller.

What you need to know about lithium ion batteries?

First of all, the restrictions that must be observed during operation:

recharge voltage (maximum) cannot be higher than 4.35V;
its minimum value cannot go below the 2.3 V mark;
the discharge current should not more than double the capacity value. If the value of the latter is 2200mAH, the maximum current is 4400mA.

Functions performed by the controller

What is a li ion battery charge controller for? It serves several functions:

supplies a current that compensates for the self-discharge. Its value is less than the maximum charge current, but more than the self-discharge current;
implements an efficient charge / discharge cycle algorithm for a specific battery;
compensates for the difference in energy flows while charging and providing energy to the consumer. For example, when charging and powering a laptop;
measures the temperature in case of overheating or hypothermia, preventing damage to the battery.

The li ion battery charge controller is made either as a microcircuit built into the battery, or as a separate device.

It is better to use the included 18650 li ion battery charger to charge the batteries. The 18650 lithium battery charger usually has a charge level indication. Most often it is an LED, which indicates when the charge is in progress and its end.

On more advanced devices, you can track on the display the time remaining until the end of the charge, the current voltage. For a 18650 battery with a capacity of 2200mA, the charging time is 2 hours.

But, it is important to know what current to charge a li ion 18650 battery with. It should be half the nominal capacity, that is, if it is 2000 mAh, then the current is optimal - 1A. Charging the battery with a high current, it degrades quickly. When using low current, it will take longer.

Video: How to charge a Li ion battery charger with your own hands

Battery charger circuit

It looks like this:

The circuit is reliable and repeatable, and the included parts are inexpensive and readily available. To increase the battery life, competent charging of li ion batteries is required: by the end of charging, the voltage should decrease.

After its completion, i.e. when the current reaches the zero point, charging of the li ion battery should stop. The circuit above satisfies these requirements: a discharged battery connected to the charger (VD3 lights up) uses a current of 300mA.

The ongoing process is indicated by a lit LED VD1, a current gradually decreasing to 30 mA, indicating that the battery is charging. The end of the process is signaled by the lit LED VD2.

The circuit uses an operational amplifier LM358N (you can replace it with an analogue of KR1040UD1 or KR574UD2, which has a different pinout), as well as a VT1 S8550 transistor 9 LEDs of yellow, red and green colors (1.5V).

Can the battery be reanimated?

After a couple of years of active use, batteries lose their capacity catastrophically, creating problems when using your favorite device. Is it possible and how to restore a li ion battery while the user is looking for a replacement?

Recovery of a li ion battery is possible for a while in several ways.

If the battery is swollen, i.e. has ceased to hold a charge, which means that gases have accumulated inside.

Then proceed as follows:

the battery case is carefully disconnected from the sensor;
separate the electronic sensor;
find a cap with control electronics under it and pierce it carefully with a needle;
then, find a heavy flat object, in area larger than the area of the battery, which will be used as a press (do not use a vice and similar devices);
put the battery on a horizontal plane, and press down with a press, remembering that the battery can be damaged by applying excessive force. If it is not enough, the result may not be achieved. This is the most crucial moment;
it remains to drip epoxy onto the hole and solder the sensor.

There are other ways, which you can read about on the Internet.

You can find a charger on the website http://18650.in.ua/chargers/.

Video: Li-ion batteries, tips for using li-ion batteries