What to expect for all of us in a few years is difficult to predict, since technological progress is developing incredibly quickly, striding not by leaps and bounds, but rushing with incredible speed... Fantastic ideas are born in the minds of engineers, which after a short period of time become reality. Charging phones, eliminating any wires, is now quite possible. However, many users still cannot figure out how a wireless charger for a phone works, believing that such manipulations are on a par with fantastic deeds.
You can now charge your smartphone using a wireless device.
If you are tired of unraveling the cords every time you need to charge your smartphone, then it is really useful for you to consider an alternative form of energy transfer. In order to consciously approach such a process, eliminating any doubts, it is useful to understand what the principle of the direct operation of wireless charging is.
Having heard for the first time that there is a wireless charger for a phone, many smartphone owners begin to fantasize on their own, convincing themselves that the distribution of energy will occur at any distance. This is, of course, an incredible misconception. In no case should a wireless phone charger be compared to Wi-Fi.
Trying to figure out how wireless charging works, it will be useful to familiarize yourself with additional information, from which it will become clear that charging that excludes the use of wires is a type of magnetic induction charging.
If you decide to get a wireless charger, start actively using it, it won't hurt you to delve into the principle of wireless charging for your phone.
Wireless power transmission technology
Scientists are in active search innovative technologies, empowering users, focused on the constant use of modern gadgets. In particular, modern researchers are ready to declare that electricity can be successfully distributed using a laser, sound waves and many other physical phenomena. However, most of these technologies are still under active development.
Among them, there is one technology that is already actively used and with great success in commercial purposes. It was the transmission of electricity using electromagnetic induction that formed the basis of modern innovative developments, which made it possible to practically implement the principle of wireless charging for a phone.
At any technical sphere there are certain standards, which are important to consider when inventing or improving devices aimed at maintaining the performance of modern gadgets.
Seven years ago, the Wireless Power Consortium developed a standard focused on the transmission of electricity wirelessly. This standard is referred to as the Chinese word Qi.
Most smartphone manufacturers not only actively welcome such a unique standard focused on charging a gadget without using wires, but also apply the Qi standard in the production of their products.
For this reason, being at bus stations, railway stations, airports of economically developed countries of the world, a person gets the opportunity to charge his smartphone without burdening himself with looking for free sockets. In such crowded places, special charging stations are installed, allowing everyone in need to use wireless charging.
How wireless charging works
If you understand how wireless charging for a phone works, it becomes clear that to ensure contact between the receiving and emitting devices, they are equipped with special induction coils. Surely, no matter how hard you try to recharge your mobile phone old model, being in close proximity to such a dispensing station, you will not succeed, since the gadget was not directly equipped by the manufacturer with such coils.
The principle of wireless charging of the phone is the formation of a magnetic field. In particular, after connecting charging station the induction coils in the mains create a magnetic field. If a device that supports the Qi standard falls into this magnetic field, it begins to actively absorb electromagnetic waves, and then, using the built-in induction coil, convert them into energy, ensuring a confident charging process battery.
It's important to understand how to use wireless charging. You cannot assume that you can charge your smartphone while at a decent distance from the charging station. It is recommended to place a discharged gadget at a distance not exceeding five centimeters.
Even if you hoist your smartphone directly onto the wireless charger itself, the efficiency of such charging will be about 80%. Of course, those who are used to getting the most useful from the manipulations carried out will easily notice that charging the phone with a wire still has a higher efficiency.
By doing a hands-on experiment and calculating how much different charging times are when using traditional and alternative charging, it becomes clear that to fully charge the battery when using wireless technologies, you will have to count on an additional time of about one hour.
Qualitative characteristics of the device
If you have studied the question of how to use a wireless charger for your phone, it does not hurt at all to familiarize yourself with its advantages and disadvantages, its effect on human health. Armed with this knowledge, it will be much easier to make the final decision.
Advantages and disadvantages
The main advantage is that you no longer have to connect wires to the smartphone itself, which are often lost, twisted, fall into the clutches of pets, and therefore are seriously damaged.
Unfortunately, you won't be able to completely forget about the wires. Wires are excluded only in relation to the smartphone, but the charger itself is still connected to the outlet using wires and an electrical plug.
Another disadvantage that can cause disappointment for the purchaser is the sufficient duration of charging the mobile device.
If you decide to purchase such an innovative device, you will also have to tune in to the fact that the cost of wireless charging is several times higher than the wired counterpart.
Impact on health
Each working mechanism emits electromagnetic waves. A modern person who cares about his health is concerned about the question of how harmful such radiation is, whether the risk of pathological changes in the body is excluded when being in close proximity to a working wireless charger.
The anxiety is understandable, since from time to time articles appear in the media in which the reader's attention is drawn to the dangers provoked by modern technical means... However, experts assure that these are nothing more than myths, since the danger to human health is completely excluded.
IMPORTANT. The electromagnetic waves involved in the wireless charging process are accompanied by a low frequency, so any negative impact on a person is excluded.
The same waves pass through a person every day, but technical progress has nothing to do with this. Exactly such waves in strength and frequency are radiated by the sun.
In addition, it is important to understand that hardly anyone will constantly stand near the charger throughout the entire cycle of its operation. For this reason, engineers, doctors and other specialists confidently refute the myth about the harm of memory to human health.
Varieties of wireless chargers
Having familiarized themselves with the advantages and disadvantages of chargers that exclude the use of wires, many users have an active desire, despite the high cost, to still become its owner.
Currently, manufacturers are ready to offer several options for such devices, so before making a purchase, it is useful to understand their distinctive featuresto understand which model can rightfully be considered the best.
Popular charging
Samsung, accustomed to surprising consumers, has not ignored the issue of creating a wireless charger. As a result of the company's work on such technical problem Samsung Wireless Charging Pad
Many users welcome it because it allows charging a smartphone, which can be in any position relative to the top surface of the charging itself.
Samsung Wireless Charging Pad charges smartphones that support not only WPC but AW4P and PMA.
Another device, the PowerBot, is also very popular. It is welcomed by the consumer that:
- itself can be connected not only to the mains, but also to a laptop;
- has an acceptable cost;
- accompanied by a high level of reliability;
- the manufacturer guarantees a long operational period.
Another wireless device Nokia DT-910 provides fast charging smartphones. In addition, the manufacturer has endowed it with many additional and very useful functions, any person who becomes the owner of such a device can deal with them.
So, in the retail network, you can easily find, and if you wish, purchase a wireless charger of a certain type. Since there is no risk to health in the further use of such a product, if there is an appropriate amount, you can purchase such a device in order to subsequently allow yourself to expand the possibilities for recharging your smartphone.
Charger - a device for charging electric batteries with the energy of an external source; as a rule, from a 220 volt alternating current network.
The charger consists of:
- voltage converter (transformer, pulse power supply);
- rectifier;
- voltage stabilizer;
- devices for controlling the current strength or the charging process;
- ammeter or LED indicators.
Types of chargers:
- built-in;
- external.
Charger typesfor nickel-cadmium and nickel-metal hydride batteries:
1. Chargers of normal (slow) charge
2. Fast Chargers
3. Chargers high-speed charge
Normal (slow) charge chargers.
Use only nickel-cadmium batteries to charge. Chargers of this type, sometimes called night chargers, are the cheapest of all types of batteries. Normal charge current is 0.1 s, charge time is 14-16 hours, with such a small current and long charge time it is difficult to determine the end time of the charge For this reason battery readiness indicator in chargers for normal charging is usually absent.
If the charging current is set correctly, a fully charged battery is slightly warm to the touch and does not need to be immediately disconnected from the charger. The battery can remain in it for more than one day. However, it is best to unplug the charger immediately after charging.
Slow chargers should not be used to charge small batteries as they are designed to work with larger batteries. In this case, the battery will begin to heat up when it reaches 70% of its capacity.
And if an insufficiently powerful charger is used to charge a powerful battery, the battery will remain cold during charging and will never be fully charged. Then it will lose some of its capacity.
Fast Chargers.
They are used to charge both nickel-cadmium and nickel-metal hydride batteries. They are characterized as mid-range chargers in terms of charge speed and price. The batteries are charged in them within 3 - 6 hours with a current of about 0, ЗС. As a necessary element, these chargers have a circuit for controlling the achievement of a certain voltage by the batteries at the end of the charge and turning them off at that moment. Fast chargers provide better battery maintenance than slow chargers. They have now given way to high-speed chargers.
High-speed chargers.
They are used to charge both nickel-cadmium and nickel-metal hydride batteries. The main advantage of high speed chargers is shorter charging times. Although due more power voltage source and the need to use special monitoring and control units, such chargers have the highest prices. The charging time in chargers of this type depends on the charging current, the degree of discharge of the batteries, their capacity and type. With a charge current of 1C, a discharged nickel-cadmium battery is charged on average in less than one hour. If the battery is fully charged, some chargers go into recharge mode with a reduced charge current and turn off by a timer signal.
Charger operating rules
- place the charger on a flat surface before turning on the charger;
- Protect the charger from dust, dirt, food, liquids, overheating and hypothermia, as well as from direct sunlight;
- if the storage conditions of the charger change, which are accompanied by a sharp drop in temperature and humidity, condensation may form inside or outside it. Allow moisture to evaporate before using the device. This will help prevent damage to the charger.
- when moving the charger from a cold to a warmer environment or from a warm to a cold environment, do not turn on the power until the device temperature matches the ambient temperature;
- when disconnecting the cable from the network, grasp the special loop on the plug. Do not pull on the cable. When prying apart, keep the connectors straight to avoid bending the pins. Likewise, make sure the correct orientation and alignment of the connector parts before connecting the cable.
Storing the charger
The charger in the original packaging should be stored in ventilated rooms at an air temperature of + 1 ° to + 40 ° C, relative humidity up to 80%, in the absence of gases and alkalis in the air, acid vapors that cause corrosion.
A car battery is electric battery , designed to provide energy automotive systems (injector, control unit, starter and others). But it cannot work forever, so it must be recharged periodically. Chargers are used for recharging.
Charging device for car battery Is an indispensable item for any vehicle owner. Indeed, quite often it happens that the engine simply does not want to start, and the reason for this lies in a weak battery charge (and it is the battery that starts the engine). In this case, the charger comes in handy. A ready-made battery charger can be purchased at a specialized store or you can make it yourself.
1. The principle of the charger.
Battery charger car battery Is a specially designed device that is designed to recharge the battery in vehicles. The essence of the car battery charger is that it converts the voltage from a standard 220 V AC network into a DC voltage corresponding to the parameters of the car battery.
The car battery charger in the classic configuration consists of twomain elements:
1. Transformer.
2. Rectifier.
The charger generates 14.4 VDC (not 12 VDC). This voltage value is used so that the current can pass through the battery. For example, if the battery was not fully discharged, then the voltage on it will be 12 V. In this case, it will not be possible to recharge it with a device that also has 12 V at the output. Therefore, the voltage at the output of the charger should be slightly higher. And the optimal value is considered to be 14.4 V. It is even more undesirable to overestimate the charging voltage, since this will significantly reduce the battery life and may disable it.
The battery charging process starts when the device has been connected to the battery and to the mains. Because lead acid battery it is necessary to charge according to a special algorithm, then the charger produces a charge with stabilization of current and voltage. This process consists of many stages.
While the battery is being charged, its internal resistance increases and the charging current decreases. When the voltage on the battery approaches 12 V, and the charging current drops to 0 V, this means that the charging was successful and you can disconnect the charger.
It is customary to charge batteries with current, the value of which is 10% of its capacity... For example, if the battery capacity is 100 Ah, then the best value is charging current is 10 A, and the charging time will take 10 hours. The current can be increased to speed up the battery charge, but this is very dangerous and has a negative effect on the battery. In this case, you need to carefully monitor the temperature of the electrolyte and if it reaches 45 degrees Celsius, the charging current must be immediately reduced.
Adjustment of all parameters of the chargers is carried out using control elements (special regulators), which are located on the body of the devices themselves. Ensure good ventilation during charging in the room where it is being charged, as the electrolyte releases hydrogen, the accumulation of which is very dangerous. An explosion can occur from one spark. Also, when charging, remove the drain plugs from the battery. After all, the gas released by the electrolyte can accumulate under the battery cover and lead to ruptures of the case.
2. What kind of chargers are there?
Chargers can be classified according to several criteria. Depending on the method used for charging, chargers are:
1. Such that they produce direct current charging.
2. Such that charge from constant voltage.
3. Such that charge by the combined method.
DC charging must be carried out at a charge current of 1/10 of the battery capacity. Such charging is able to fully charge the battery, but the process will require control, because during it the electrolyte heats up and can boil, which causes a short circuit and fires the battery. Such charging should not last more than one day. DC charging is much safer, but it does not fully charge the battery.
Therefore, modern chargers use a combined charging method. With this method, charging is first performed from direct current, and then switches to charging from constant voltage in order to prevent overheating of the electrolyte. Depending on the features of work and design, chargers for car batteries are divided into two types:
1. Transformer. Devices with a transformer connected to the rectifier. Such devices are reliable and efficient, but they are very bulky (they have large dimensions and noticeable weight).
2. Impulse. The main element of such devices is a voltage converter operating on high frequencies... This is the same transformer, but much smaller and lighter than that of transformer chargers. It is for this reason that this type of charger has become very popular among motorists lately. In addition, most of the processes of impulse devices are automated, which greatly simplifies their control.
Depending on the purpose, chargers are two species:
1. Charging and pre-starting. Charges the car battery from an available power source.
2. Charging and starting.
They are able not only to charge the battery from the mains, but also to start the engine when it is discharged. Such devices are more versatile and can supply 100 volts or more if you need to quickly charge the battery without an additional source of electrical current. There is also a separate class of chargers - solar chargers. They make it possible to charge the battery without connecting to the mains. Charging takes place using a block solar batterythat stores energy from the sun. And the device itself is connected to the cigarette lighter or to the battery terminals. Such devices are very convenient to use if the battery is dead and there is no power supply nearby.
3. What to look for when choosing a charger?
Tips to consider when choosing a car battery charger:
1.
Before you go to the store to buy a charger, you need to thoroughly study the manual for your battery and operation. on-board network... In the store, you should study the characteristics of the chargers and only then choose the right model.
2. As for the manufacturing country, there is only one advice - it is better not to buy products from China, since counterfeit products are very often imported from this country. It is better to give preference to a domestic manufacturer.
3. It is worth choosing a charger with a current margin so that it does not function at the limit of its capabilities, which reduces its service life. You may also need to charge the battery in the future. larger capacityand you don't have to buy the charger again.
4. Better to choose automatic device with a combined charging method. It is easier and easier to operate with such a device (usually such devices have only one regulator), and in terms of functionality they are very reliable. They are perfect for beginners.
5. You should buy the device only from official dealers, because the state of all automotive electronics depends on its quality.
6. If you plan to actively operate the car in winter time, it is better to purchase a charger and starting device. In this case, you should also pay attention to the presence of the Boost function, which allows you to recharge the battery in a few minutes.
Now there are many models of chargers on the market, both from world leaders and more affordable options from less well-known manufacturers. Well-established battery charger manufacturers include Aiken, Telwin, Resanta, Caliber, Sorokin.
4. A simple circuit for making a charging.
If suddenly the battery in the car is discharged, and you do not have special chargers for it, then you can make them yourself using the parts available on the farm. To make your own charger you will need:
1. Transformer (lowers voltage from 220 V to 14-16 V).
2. Power plug (delivers current from the mains to the device).
3. Mains fuse (protects the circuit against short circuits).
4. Wire rheostat (regulates the strength of the charging current).
5. Ammeter (controls the amount of charging current).
6. Rectifier (converts alternating current to permanent).
7. Switch (turns on / off the device).
8. Light bulb (signals the appearance of voltage on the transformer winding).
9. Rheostat (regulates the current and voltage in the assembled electrical circuit).
10. Dielectric material (needed in order to make the device case and mount all the elements on it).
Stages of the charger manufacturing process:
1. If there is no ready-made rectifier device, then it must be made of diodes by assembling a rectifier bridge from them. The device must be mounted on a dielectric (plastic, plywood, textolite, etc.).
2. Mount the transformer at the base of the rectifier.
3. Solder the mains fuse to the mains plug and connect to the transformer.
4. Assemble the body of the device from dielectric material and make holes in it for cooling and free air circulation around the rectifier and transformer.
5. On the front wall of the housing, fix the light bulb, switch, rheostat and ammeter.
6. Equip the output wires from the rectifier with terminals with different diameters (so as not to reverse the polarity when connected to the battery).
7. Connect all the elements together by assembling the simplest electrical circuit.
After the charger is assembled, you can connect its plug to the electrical network, connect the terminals to the battery and set the required current for charging with a rheostat, monitoring its value with an ammeter.
Nowadays, every family has a large number of electronic devices... Phones, smartphones, flashlights, tablets, toys for children of all ages and many other household appliances require power from portable power sources: batteries or rechargeable batteries.
Power supplies are designed for long-term operation, but can quickly fail due to carelessness. To make the most of the manufacturer's resource inherent in them, we recommend that you familiarize yourself with the operating features of batteries of various designs, the rules for charging and safe handling.
The most impatient readers can go straight to the charging rules recommended by the factory. They are listed at the end. However, consistent reading of the material will allow you to better understand their features and correctly apply them in practice.
How the battery works and works
The entire wide range of battery products works on the same principle of energy conversion chemical processes into electric. A special design has been created for its flow.
Battery principles
A sealed vessel called a jar is filled with electrolyte. In it are placed two separated from each other plates of different metals, called electrodes. An electrical potential difference is formed on them, which is capable of performing useful work.
To increase the power of energy, cans with plates are made oversized or connected in parallel chains. To raise the output voltage, they are connected in series. Such designs are called rechargeable batteries.
Classification
By type of electrolyte, batteries are divided into:
- liquid;
- gel.
By design features liquid accumulators are divided into:
- acidic;
- alkaline;
- saline.
Constructions acid batteries are used relatively rarely. They can be found in budget models of flashlights, where they work in conjunction with a charger.
Batteries alkaline type, as a rule, have increased dimensions. Previously, they were used for lighting in portable lamps, but now such structures are not convenient for work and have ceased to be used.
IN mobile devicesah for home use popular battery models:
- lead acid (Pb + H 2 SO 4);
- nickel-cadmium (Ni-Cd);
- nickel-zinc (Ni-Zn);
- nickel metal hydride (Ni-Mh);
- lithium-ion (Li-ion);
- lithium polymer (Li-Pol)
Design features of various models
A typical device of a battery of accumulators, consisting of separate cans with a set of positive and negative plates inserted into them, the sequence of their arrangement can be observed on the example of an acid battery.
The designs of the cylindrical or "finger" models are a cutaway view for a lithium-ion battery, with explanatory text for each layer.
Battery appearance
The dimensions and shape of the current sources are created for their convenient location in the sockets of mobile devices, reliable power supply to consumers, and the possibility of fast charging.
Batteries can be in the form of a cylinder or a tablet, as shown in the photo for common nickel-cadmium devices, which are assembled into blocks with special jumpers.
When, according to the operating conditions, it is preferable to receive power from a single unit, then a common case is created. Separate finger elements are built into it, which, due to their parallel and serial connection, provide output characteristics for current and voltage.
This is the principle behind the creation of laptop batteries.
For small-sized mobile devices, batteries are created in the form of a small parallelepiped with rounded edges. On one of the end sides it has brass platforms mounted, which provide an electrical contact for the source and current consumers.
The principle of converting chemical energy into electrical energy of interest to us is explained by the picture.
A redox chemical reaction takes place between two adjacent substances with selected properties. It is accompanied by the release of electrons and ions, which, as you know, form electricity.
So that moving charges create electrical potentials, and not just generate heat in environment when mixing an oxidizing agent with a reducing agent, it is necessary to create conditions for this.
These purposes are served by:
- anode (positive charge) that carries out an oxidative reaction;
- reducing substance cathode;
- electrolyte, conducting current during the dissociation of the working medium into cations and anions.
The anode with the cathode are placed in distant vessels that are connected by a salt bridge. Anions and cations move along it, creating an internal battery circuit. The external circuit is formed by connecting a consumer to an input, for example, a voltmeter or other load.
At the anode and cathode, electrons and ions are constantly being transferred to the electrolyte and vice versa. In the inner chain, charges move through the salt bridge, and in the outer chain, current flows from the anode to the cathode.
This principle is the basis for charging and discharging all models of chemical current sources.
How Nickel Cadmium Battery Works
There are only two types of work:
- discharge;
- charge.
You can also distinguish the storage mode, but it is more correct to class it as a category that they try to limit as much as possible, although it cannot be completely avoided.
Discharge cycle
The energy accumulated on the electrodes, when a load is connected to them, creates an electric current in the external circuit.
Anode in nickel cadmium battery nickel oxides work with inclusions of graphite particles, which reduce the total electrical resistance. Spongy cadmium is used as the cathode.
During the discharge, active oxygen molecules are released from the composition of nickel oxides, which enter the electrolyte and further to cadmium, oxidizing it.
Charge cycle
It is customary to carry out it when the load is removed. Then you can use less power of the charger.
The polarity of the terminals of the charger and the battery must match, and the external power must exceed the internal one. Then, under the action of an external source, a current is formed inside the battery bank with a direction opposite to the discharge.
It reorients the course of chemical processes in the jar, enriches the anode with oxygen and reduces cadmium at the cathode.
How does a lithium-ion battery work
A carbon anode and a cathode of metal oxides containing lithium, for example, of the composition LiMn 2 O 4, are immersed in an organic electrolyte.
Positively charged Li + ions move in it. In this case, lithium itself does not go into a metallic state, but an exchange of its ions between the electrode plates is created. For this reason, batteries are called lithium-ion batteries.
Charge cycle
Lithium ions are removed (deintercalation process) from the lithium-containing cathode and incorporated into the anode (intercalation).
Discharge cycle
The movement of ions goes in the direction opposite to the charge, and the electrons from the anode move to the cathode and form an electric current.
If we compare the principles of operation of a battery of any design, then we can observe the general pattern of movement of ions between the electrodes along the internal circuit and electrons along the external circuit when creating charge and discharge circuits.
Battery performance
Working voltage
Its value is determined at the open terminals with a voltmeter at an optimal charge. In the process of work, it gradually decreases.
Battery capacity
A characteristic showing the amount of current in milliamperes or amperes that a battery can deliver over a period of time, expressed in hours.
Power
A parameter that takes into account the ability of the battery to perform work per unit of time.
How a mobile device battery charger works
Now all expensive electronic devices are supplied with their own power and charging devices.
Separate chargers are available to restore the performance of batteries used individually. They are accompanied by instructions and tables indicating the recommended duration of the technological cycle.
Such models usually provide a stabilized voltage to the terminals of the battery, which, during charging, gradually changes its electrical resistance, which affects the amount of current flowing. Therefore, these recommendations are of an average nature.
Forms of currents generated by chargers
To charge batteries, not only direct currents can be used, but also many other types that solve specific problems.
To ensure their flow, various electronic circuits, which supply the corresponding voltage to the battery terminals.
Schematic diagrams of chargers
In view of their variety, we will give as an example some typical solutions.
Constant current generation circuit
The transformer lowers the voltage. Its harmonic is rectified by a diode bridge and ripple is smoothed out by a high-capacity capacitor.
Constant currents are supplied to the battery output.
The scheme for creating pulsating currents
By removing the capacitor from the previous chain, we obtain voltage ripples at the battery terminals, which form currents of a similar shape.
Scheme for creating pulsating currents with a gap
Replacing diode bridge with a single diode we obtain the ripple of currents of increased frequency twice.
Service chargers
By complicating the internal electrical circuit various additional functions for chargers. 
In all calculations of the value of the charging current Ic in amperes, an empirical ratio is taken as the base value, measured as a percentage of the value of the capacitance C, expressed in ampere-hours.
However, for certain models, the manufacturer may indicate the charging current immediately in numerical terms in amperes, which does not comply with this rule. It is clear that he has good reasons for this.
Lead acid batteries
It is customary to use currents for charging, amounting to 10% or 0.1 of the capacity C. They are recorded as 1C.
For these batteries, the voltage on a single cell should not exceed 2.3 V, which should be taken into account when charging the battery in order not to exceed the critical value.
The accumulation of the capacity of acid batteries after reaching 90% of the nominal value is exponential. Therefore, further charging is performed with reduced currents with control of the voltage on the banks, which increases the duration of the process.
Lead-acid batteries need periodic control training cycle with full discharge and charge.
Alkaline batteries
For them, it is customary to maintain the charge current at 25% of the capacity or 0.25C.
Nickel-cadmium battery models
The optimum temperature for charging, as well as for work, is within + 10 ÷ 30 о С. At this temperature, oxygen is better absorbed at the cathode.
Cylindrical accumulators are mounted by tightly wound electrodes into a roll. This makes it possible to efficiently charge them with currents within a wide range of 0.1 ÷ 1C. The standard mode provides currents of 0.1C and a time of 16 hours. At each element, the voltage rises from one to 1.35 V.
If an overcharge control system is installed in the charger, then increased currents of constant form with a value of 0.2 ÷ 0.3C are used. This allows charging times to be reduced to 6 or 3 hours. Even an overcharge is admissible within 120 ÷ 140%.
A characteristic drawback of nickel-cadmium batteries is the "memory" effect or reversible loss of capacity, which manifests itself in violation of the charging technology, or rather, after the start of recharging a battery with an incompletely consumed capacity.
The accumulator “remembers” the limit of the remaining reserve and, upon subsequent discharge to the load, reduces its resource when it is reached. This feature is taken into account during operation, and for storage of Ni-Cd batteries, they are transferred to a full discharge mode.
Nickel Metal Hydride Battery Models
They were created to replace nickel-cadmium batteries, have no memory effect, and have increased capacity. But, when preparing for work after a month or more of storage, a full discharge cycle is required, followed by charging. After completing 3 ÷ 5 such cycles, you can increase the working capacity.
To store these batteries, their capacity is converted to 40% of the nominal value.
Charging is carried out using 0.1C technology for nickel-cadmium batteries, but with temperature control. Its excess over 50 О С is unacceptable. Strong heating occurs at the end of the cycle when the chemical reactions slow down.
For these reasons, dedicated chargers with built-in temperature sensors are being created for nickel-metal hydride batteries.
Nickel-zinc battery models
The voltage of one can is 1.6 V. The charging current is 0.25C. Charge time 12 hours. There is no memory effect. The recommended limit for reaching capacity when charging is 90% of the nominal.
Do not heat more than 40 ° C. Limited resource - three times shorter than that of nickel-cadmium batteries.
Li-ion battery models
Optimal charging in progress direct current in two stages with a value:
- 0.2 ÷ 1C with a voltage of 4 ÷ 4.2 V in the first 40 minutes;
- maintaining a constant voltage on the bank of 4.2 V until the end of the cycle.
Charging with 1C current for 2 ÷ 3 hours is permissible.
Lithium-ion battery life is reduced by:
- charging voltage greater than 4.2 V;
- recharge accompanying the accumulation of lithium at the cathode and the evolution of oxygen at the anode.
As a result, there is a rapid release of thermal energy, an increase in pressure in the casing, and depressurization.
In order to improve safety during operation, the manufacturers of these batteries apply one or more protection measures during charging:
- circuit for switching off the charging current when the temperature in the case reaches 90 ° C;
- overpressure sensor;
- charging voltage control system.
Since the lithium-ion battery works and charges inside expensive electronic devices, it should be charged with care, using only specialized chargers.
Features of charging by depth of discharge
Features of charging by temperature
The correct choice of these parameters can significantly extend the service life of lithium-ion batteries.
Lithium polymer battery models
All operating rules developed for lithium-ion models are suitable for them. But, since there is no liquid electrolyte in them, and a gel-like one is used, then when recharging or overheating, an explosion of the case is excluded, which can only swell.
Understanding the principles of how the battery and charging for mobile devices work will help extend the life of your gadgets, operate them reliably and safely.
To consolidate the material, we suggest watching the video of the owner of Admiral134 "How to use lithium-ion batteries correctly."
It is now convenient for you to ask a question in the comments and send this material to your friends on the social network.
I wonder what the Siemens charger (power supply) consists of and whether it is possible to repair it yourself in case of a breakdown.
First, the block needs to be disassembled. Judging by the seams on the case, this unit is not intended for disassembly, therefore, the thing is disposable and in the event of a breakdown, one can not pin high hopes.
I had to literally raskurochit the case of the charger, it consists of two tightly glued parts.
Inside is a primitive board and a few details. Interestingly, the board is not soldered to the 220V plug, but is attached to it with a pair of pins. In rare cases, these contacts can oxidize and lose contact, and you think that the block has broken. But the thickness of the wires going to the mobile phone connector pleased me pleasantly, you don't often find a normal wire in disposable devices, usually it's so thin that it's scary to even touch it).
There were several details on the back of the board, the circuit was not so simple, but still it is not so complicated that you would not be able to fix it yourself.
Below in the photo are the contacts of the inside of the case.
There is no step-down transformer in the charger circuit; an ordinary resistor plays its role. Then, as usual, a couple of rectifying diodes, a pair of capacitors for rectifying the current, then a choke and finally a zener diode with a capacitor complete the chain and output the reduced voltage to a wire with a connector to a mobile phone.
The connector has only two pins.
