The battery is a device that tends to discharge over time. This process is characterized by a decrease in voltage without load (with the terminals removed). A dead battery is also called a “dead” battery. There are several ways to restore battery charge, which are described below.
How to properly charge a car battery and what devices and equipment are needed for this is of interest to every car enthusiast. This problem becomes especially relevant given the limited funds allocated for the maintenance of automotive equipment. The rules for carrying out this procedure ensure not only the safety of expensive devices, but also the safety of the car owner himself.
To charge the battery, a charger is required, but they differ in design and application. All types of such chargers have a similar operating principle, which is based on converting alternating current from a household electrical network into direct current.
The circuit of such devices can include variators - modules that change the voltage (12/24 Volts), time relays that turn off the power after a specified time, various indicators in the form of signal lamps or information liquid crystal displays and other components. To charge a regular car battery with a nominal voltage of 12 V, you need a charger that produces 16-17 V DC at the terminals.
The starter battery itself can be charged in various places where there is access to a household electrical outlet and a power outlet. When charging, the battery can not even be removed from the car or placed on a flat surface in the garage or even in the apartment. In this case, it is necessary to carefully follow safety regulations.
First of all, before charging, the battery should be cleaned of foreign contaminants, dust and dirt should be removed and the terminals should be carefully removed. After this, you need to check the case for mechanical damage, the electrolyte level, make sure that it is not leaking, and only then begin the process itself.
All operations with the battery must be carried out with chemical-resistant rubber gloves, since the electrolyte can severely damage the skin. If the battery design allows, the plugs are unscrewed from it. During the inspection, you should check the electrolyte level in all banks and its condition.
A normal electrolyte should be transparent and colorless. To do this, you can use a hydrometer flask. The presence of sediment, flakes, suspension in the solution, or a change in color and transparency indicates that not everything is in order with the battery. Most likely, there is a short circuit in the plates in the “dirty” jar. This battery cannot be charged.
If the electrolyte in all banks is clean and transparent, you can begin the charging process. The main rule when connecting the charger terminals is first they are connected to the battery, and only after that it can be connected to the power supply. This rule is very important!
There are three methods used to charge the battery:
— Charging using constant voltage;
— Charging using direct current;
— Combined charging method.
Constant voltage charging
The constant voltage charging mode of the battery connects the charge level and the voltage value during charging. If we are talking about charging a 12 V battery, then at a constant voltage of 14.3 V it will charge in approximately 48-50 hours. When the voltage increases to 16.6 V, the charging time decreases to 20-22 hours.
When connecting the charger to a completely discharged battery, the current in the circuit can reach 50 A. This can lead to failure of electrical devices that are in the circuit. Therefore, a module is included in the circuit of all chargers that limits the current to 20-25 amperes.
Electrochemical processes in the battery, which are activated when the charger is connected, are aimed at equalizing the voltage between it and the battery terminals. The current strength in the circuit will gradually decrease.
When the battery is fully charged, the current in the circuit drops to zero. Most devices provide a signal with an indicator lamp or LED. A fully charged battery should read 14.4 V across the terminals.
Charging at constant voltage is the “softest” method for equipment and safest for humans. When charging the battery in this way, it can be left unattended without fear of dangerous situations.
Constant current charging
Using the constant current method requires care and attention throughout the charging process. In this case, it will be necessary to constantly adjust the current strength during charging, checking the indicators of the devices at least every hour and carrying out the necessary manipulations. A standard 55 Ah battery will be charged in this way in approximately 10 hours at a charging current of 6 A.
When the nominal voltage reaches 14.4 V, the current is reduced to 3 A. As soon as the voltage at the terminals reaches 15 V, the current should be reduced by half more - to 1.5 A.
If the charging voltage does not change for one and a half to two hours, then the charging process can be completed. At the end of charging, the cans begin to “boil”, i.e. the electrolysis process is activated, which is an obvious disadvantage of this method along with the need for constant monitoring.
Combined charging
Industrial chargers that are currently offered on the market are based specifically on the combined charging method. At the beginning of the charging process, a current of constant strength is supplied, which makes it convenient to use in a household electrical network (since peak values leading to excessive load are not reached), and at the end of charging, the device maintains a constant voltage, which prevents the electrolyte from “boiling” .
Combined chargers, as a rule, are adapted for autonomous operation and do not require operation control. When the battery is fully charged, they can automatically turn off.
There are other ways to charge car batteries - forced, pulsed, pulsating or asymmetrical current, according to Woodbridge et al. However, in practice, chargers that use the principles described above are most often used.
The CT5 START/STOP charger is the result of the productive work of CTEK specialists, who have developed a model that allows for a simple way to charge starter batteries installed on vehicles equipped with a modern Start-Stop system.
All that is required from the user is to connect the charger to the battery and insert the plug into the outlet. Charging will start automatically. Without the need to select a mode, you can handle the task of servicing the battery quickly and easily and solve a number of problems related to battery operation.
Battery type Lead-acid batteries 12 V (incl. WET, MF, Ca/Ca, and GEL). Optimized for AGM and EFB Battery capacity From 14 to 110 Ah (charging) to 130 Ah (recharging) Charger type Fully automatic charger Charging voltage 14.55 V Charging current 3.8 A maximum Minimum residual voltage 2.0 V Power fluctuations current<1,5 Ач/месяц Утечка обратного тока - Класс защиты IP65 (брызгозащитное и пыленепроницаемое исполнение) Номинальное напряжение электросети 220-240 В перем. тока, 50-60 Гц Температура окружающей среды От -20°C до +50°C, выходная мощность автоматически понижается при высокой температуре Охлаждение Естественная конвекция Габаритные размеры 168 х 65 х 38 мм Вес 0,6 кг Гарантия 5 лет Длина питающего кабеля 140 Длина соединительного кабеля 150
If you are a private person, then you cannot buy a charger from us. Our company does not carry out retail sales to individuals. We work only with our dealers and legal entities. You can find our dealers on our website in the section Where can I buy. You can also make an application to one of our dealers.
GEL batteries and other types of lead-acid batteries charge perfectly with CTEK chargers. Gel batteries should be charged at a voltage of no more than 14.4 Volts. Depending on the model of the STACK charger, you charge in the "NORMAL" mode or select the "Car" mode. Please note that you cannot charge GEL batteries in the "RECOND" mode, because Gel batteries are extremely sensitive to increased voltage
The battery is considered discharged if the voltage in it drops below 10.5 Volts, while it can still work until the voltage in it reaches 7-8 Volts. Most CTEK charger models can restore a battery down to 2 volts. Model XS 0.8 restores batteries with a capacity of up to 32 Ah, discharged to 6 Volts. Information about the minimum residual voltage is displayed in the technical specifications of each model. CTEK chargers have an automatic pulse mode, and some have a “soft start” mode for restoring sulfated batteries. Keep in mind that some types of batteries that have been deeply discharged may be completely destroyed and must be replaced.
The relatively simple charger described below (see Figure 2.59) has wide limits for regulating the charging current-practically from zero to 10 A-and can be used to charge various starter batteries of 12 V batteries.
Figure 2.59. Schematic diagram of a charger for starter batteries.
The device is based on a triac regulator with a low-power diode bridge VD1 ÷ VD4 and resistors R3 and R5. After connecting the device to the network, with its half-cycle positive (plus on the top wire in the diagram), capacitor C2 begins to charge through resistor R3, diode VD1 and resistors R1 and R2 connected in series. With a negative half-cycle of the network, this capacitor becomes infected through the same resistors R2 and R1, diode VD2 and resistor R5. In both cases, the capacitor is charged to the same voltage, only the charging polarity changes. As soon as the voltage on the capacitor reaches the ignition threshold of the neon lamp HL1, it lights up and the capacitor is quickly discharged through the lamp and the control electrode of the triac VS1. In this case, the triac opens. At the end of the half-cycle, the triac closes. The described process is repeated in each half-cycle of the network.
It is well known that controlling a thyristor using a short pulse has the disadvantage that with an inductive or high-resistance active load, the anode current of the device may not have time to reach the holding current value during the action of the control pulse.
One of the measures to eliminate this drawback is to connect a resistor in parallel with the load. In the described charger, after turning on the triac VS1, its main current flows not only through the primary winding of transformer T1, but also through one of the resistors-R3 or R5, which, depending on the polarity of the half-cycle of the mains voltage, are alternately connected in parallel to the primary winding of the transformer with diodes VD4 and VD3, respectively.
The powerful resistor R6, which is the load of the rectifier VD5, VD6, also serves the same purpose. Resistor R6, in addition, generates discharge current pulses, which extend the battery life.
Setting up a charger for starter batteries
When setting up the device, first set the required charging current limit (no more than 10 A) with resistor R2. To do this, connect a battery to the output of the device through a 10 A ammeter, strictly observing the polarity. The slider of resistor R1 is moved to the highest position according to the diagram, resistor R2 to the lowest position, and the device is connected to the network. By moving the slider of resistor R2, the required value of the maximum charging current is set.
Final operation-calibrating the scale of resistor R1 in amperes using a standard ammeter. During the charging process, the current through the battery changes, decreasing by about 20% toward the end. Therefore, before charging, set the initial battery current slightly higher than the nominal value (by about 10%).
The end of charging is determined by the density of the electrolyte or with a voltmeter-The voltage of the disconnected battery should be within 13.8 ÷ 14.2 V.
Instead of resistor R6, you can install a 12 V incandescent lamp with a power of about 10 W, placing it outside the housing. It would indicate the connection of the charger to the battery and at the same time illuminate the workplace.
Charger parts for starter batteries
The main unit of the device is transformer T1. It can be made on the basis of the LATR-2M laboratory transformer by insulating its winding (it will be the primary) with three layers of varnished cloth and winding a secondary winding consisting of 80 turns of insulated copper wire with a cross-section of at least 3 mm 2, with a tap from the middle.
When making a transformer yourself, the following parameters are set: voltage on the secondary winding 20 V at a current of 10 A,
Capacitors C1 and C2-MBM or others for a voltage of at least 400 and 160 V, respectively.
Resistors R1 and R2 - SP 1-1 and SPZ-45, respectively.
Resistor R6 - PEV-10, it can be replaced with five parallel-connected MLT-2 resistors with a resistance of 110 Ohms.
Neon lamp HL1-IN-3, IN-ZA, it is advisable to use a lamp with electrodes of the same design and size-this will ensure symmetry of the current pulses through the primary winding of the transformer.
Diodes VD1 ÷ VD4 - D226, D226B or KD105B.
KD202A diodes can be replaced with any of this series, as well as with D242, D242A or others with an average forward current of at least 5 A. The diodes are placed on a duralumin heat-sinking plate with a useful surface area, dissipation of at least 120 cm 2.
The triac should also be mounted on a heat sink plate with approximately half the surface area.
Circuits carrying load current must be made with MGShV brand wire with a cross-section of 2.5 ÷ 3 mm 2.
The Italian company DECA is located in the oldest Republic of San Marino. The company specializes in two main areas: electric arc welding and chargers for starter and traction batteries.
DECA was founded in 1972 and has since 43 years as one of the leading manufacturers of two product groups - from hobby to industrial applications. All deca products comply with the RoHS Directive (Restriction of Hazardous Substances Directive), which limits the content of potentially harmful substances in electrical and electronic products.
Charging car batteries is a task of car electrical installation. But it is also true that every battery must be charged occasionally or periodically from an external device. The need for a charger is non-negotiable. The question is how to choose the most suitable one. A choice that largely depends on the type of battery and the saturation of the car with electronic systems. Charging a battery such as an AGM or GEL using a charger, often from an unknown, almost anonymous manufacturer, can easily damage the battery. Such a device, if connected to a battery in a vehicle's electrical system, can destroy electronic components and unintentionally costly repairs.
The performance of any vehicle depends critically on the condition of its starter battery. It is subjected to continuous testing, which, in the case of insufficient competence and irregular care, can shorten its service life, and the most unpleasant thing is failures when starting the engine. This happens mainly during the winter months and again, usually at the most inopportune times.
As cars become more sophisticated - more and more and all sorts of benefits, such as electric side windows, roof and side mirrors, heated seats, powerful sound systems, handbrake, more and more energy consumption in them. The car is becoming an increasingly self-sufficient consumer of electricity, which places high demands on the generator and battery.
When the engine is idling, the alternator is running at about a third or less of its rated power, so the battery needs to provide some of the electrical power it uses, including the daytime running lights. Especially when you are in an urban environment and cover a distance of about 10 km every day, and also when using the car rarely - for example, up to 200 km per month, the battery discharges quickly, which is easily recognized by the headlight, the starter makes it difficult to turn the flywheel when it fails. This can be easily anticipated and prevented by periodically checking the battery voltage.
When using a fully charged (100%) battery, a lead-acid battery produces 13.10 V - 13.20 V. At a 90% charge level, the voltage is 12.90 V, and at 75% its value drops to 12.45%. When the battery is charged (100%), the lead-acid battery produces 13.10 V - 13.20 V. At a charge level of 90%, the voltage is 12.90 V, and at 75% its value drops to 12.45%. When using a charged (100%) battery, the lead-acid battery shows 13.10 V - 13.20 V. At a charge level of 90%, the voltage is 12.90 V, and at 75% its value drops to 12.45%.
A voltage of 12.30 - 12.35 V is considered the lower limit for the need to charge the battery immediately. If this is not done, keeping the battery at a low charge level for longer, resulting in a deep discharge, will significantly improve the sulfation process of the plates. The mass of the plates produces large crystals of lead sulfite, which block the pores and prevent the penetration of the electrolyte. These crystals are durable and cannot be removed by standard battery charging. The result is a rapid reduction in its capacity and an urgent need for a new purchase. However, it is important to know that, unlike other failures such as plate corrosion, for example, sulfation is a reversible process,
All this strongly emphasizes the need to periodically check the condition of the battery and ensure that it is properly charged. The frequency of checks depends on the type, age and condition of the battery, driving mode and season.
When city traffic prevails and especially in winter, periodic charging of the battery is recommended. Some battery manufacturers recommend that the battery be tested every three months, regardless of how the vehicle is driven, and that desulphurization and equalization charging be performed every six months. In practice, this is done using a modern charger.
Periodic recharging of batteries is also mandatory during long-term storage without use (for example, in winter). Modern chargers also have the ability to maintain a maximum charge level on connected batteries for an extended period.
Modern lead-acid starting batteries have undergone a significant evolution, and although they have retained the principle of operation discovered back in 1859 by the French physicist Gaston Plante, they are very different from open-type batteries - with cells for distilling water, measuring the level and density of the electrolyte, and open bridges between cells, etc.
The main types of rechargeable batteries currently available on the market are:
– WET – sealed liquid electrolyte batteries, little or completely unsuitable (MF);
– AGM (absorbent glass mat) – valve regulated lead acid (VRLA) battery with electrolyte absorbed into a glass pad.
– GEL – sealed batteries (VRLA), in which the electrolyte is in the form of a gel.
– Pb-Ca – for these batteries, the antimony contained in the lead alloy of the plates is replaced by a calcium alloy, which reduces the evaporation of the electrolyte and the self-discharge of the battery.
Non-rechargeable batteries, especially AGM and GEL, charging voltage and maintenance should be lower than normal. This is due to the release of gas and loss of water during the charging process. Typically, rechargeable batteries require more care when charging them from an external source.
According to DIN-VDE-0510, the charging current voltage should not exceed 2.4-2.45 V per cell (range is 2.3 V - 2.45 V). for a 12 V battery do not exceed 14.4 - 14.7 V. These batteries are most often charged with voltage current:
– Standard battery – 14.4 V maximum (2.4 V per cell)
– Uncontrolled battery – no more than 13.8 V (2.3 V per cell). The process must be monitored and controlled by the charger. The same applies to the following types of batteries.
– Jelly electrolyte battery – no higher than 14.1 V (2.35 V per cell).
The task is further complicated because the choice of charging current voltage is a compromise caused by a number of factors. Generally speaking, when the charging current is in the range of 2.30V - 2.35V, battery life is extended and battery heating is minimal. At the same time, the process duration is extended and sulfation may occur if an equalization compensator is not applied at the end of the process. With a voltage range of 2.4V - 2.45V, the charging time is shorter, the higher the battery's constant capacity, the higher the likelihood of sulfonation. On the contrary, the likelihood of irreversible corrosion of the plates increases, gas release and water shortage increase. At higher ambient temperatures, the battery can be charged, which is especially dangerous for hermetically sealed batteries. This leads to an accelerated loss of active material from the plates, and the battery loses some of its capabilities. It should be added that voltage control for each cell is not possible individually.
It should be noted that there may be minimal variations depending on the source of information in the above data references for voltage values and data in other publications. For each specific model and brand, the recommended values are indicated by the manufacturer in the technical data sheet and warranty booklet of the battery.
DECA offers starter and traction battery chargers for all vehicles, agricultural and other vehicles powered by an internal combustion engine - motorcycles, cars, trucks, buses, construction and lifting machines, boats, etc. They are designed to meet the requirements for charging all currently used lead-acid batteries (WET, AGM, GEL), which are clearly indicated on the packaging and in the technical manual of each of them.
They are divided into four main groups:
– INVERTER SERVICE – The devices are designed for charging and maintaining rechargeable batteries for cars, motorcycles and other vehicles, including when they are not used for a long time.
– ELECTRONIC FULL POWER – Professional devices designed to quickly charge batteries and maintain their full capacity.
– ELECTRONIC START STOP – A simple and economical solution for refilling traditional and new types of batteries.
– TRADITIONAL PRO CHARGE – Traditional chargers, reliable and inexpensive, for charging liquid electrolytes (WET).
Along with the SM 1236 evo, these are the two latest models in the INVERTER MAINTENANCE series – microprocessor-controlled automatic chargers. Suitable for WET, AGM and GEL battery types. The devices are hermetically sealed and therefore also suitable for outdoor use. They are suitable for charging the battery without removing it from the car.
The difference between the two models lies in the capacity of the rechargeable batteries: the SM 1236 evo is designed for 1.2 Ah – 75 Ah batteries and the SM 1270 evo for 14 Ah – 150 Ah batteries.
In addition, the SM 1270 evo is also equipped with a Recond Battery function, which allows the recovery and then normal charging of heavily diluted batteries whose voltage has dropped to a point where most automatic chargers cannot operate.
A very valuable quality of both devices is their ability to test the battery - its charge level, its ability to supply sufficient starter current when the engine is cranked (while the engine is running), and the ability of the alternator to charge when necessary for battery voltage (with the engine running). ). The score is recorded by a tricolor LED illuminated in green, yellow or red. The green color values are in the range of the normal red color - the values are below the minimum (listed in the manual), and the battery must be immediately regenerated by switching the device's equalization mode (compensation adjustment). This mode is designed specifically for restoring a severely discharged (up to 35%) battery.
The red light turning on, especially in start mode, may also indicate that it has replaced the battery. The red light in the third test alerts you to the need to check and repair the battery charging system.
At the beginning of the article, we mentioned that modern “smart” chargers have little in common with the old selenium rectifiers that are now sold due to its low price and the lack of adequate technical information to correctly guide users.
An excellent illustration of this point is the modes that the SM 1270 evo charger applies when charging, restoring or maintaining a battery charge when not in use for a certain period of time. When the mains power is turned on, the device automatically checks the battery and selects the appropriate mode. Some of these modes can also be selected directly by clicking the Set button. The charging process is a sequence of eight cycles, as can be clearly seen from the diagram - the current-voltage characteristic of the charging current.
18369_2SHere is a brief description of each of these modes.
1. The device delivers a series of current pulses that help eliminate possible sulfonation on the surface of the plates.
2. By gradually increasing the voltage, the current is maintained at a constant level until the battery can “charge” the normal charging current.
3. Charging voltage and power are increased to the optimum value to reach about 80% of the battery capacity.
4. Charging continues until 100% of the battery capacity is reached - the voltage is maintained at the achieved level, and the current gradually decreases to almost zero.
5. The device tests the battery to determine whether it can maintain the achieved charge level.
6. Initial stage of the Equalize program.
7. The device maintains maximum battery performance (float mode) for 7 days.
8. In this mode (pulse), the device keeps the battery at 95-100% power mode for extended periods of time, charging current pulses if necessary.
In addition, you can select the mode marked with a snowflake, in which the supply voltage is 14.7 V (with normal 14.1-14.4 V). This mode is also suitable for AGM batteries. Also recommended for batteries operating at temperatures below 5°C. In feed mode, the device charges at a constant voltage of 13.5 V. It is also used to initially "revive" severely diluted batteries and then charge them in the usual way.
The device is protected against incorrect connection to the polarity of the terminals, as well as sparking. It also has an LCD indicator that detects open problems during charging and possible causes.
Sleek, elegant, intelligent and expansive, the SM 1270 evo is an excellent addition to the workshop for every car, motorcycle or powerboat owner who has the desire and ability to take care of the battery, as well as for professional use.
The following two chargers are designed for professional vehicle maintenance or larger garage applications.
Model FL 3713D
typical, with most features, representative of the FL family of the ELECTRONIC FULL POWER group. It is suitable for charging 6 V, 12 V and 24 V batteries with an average charging current of 7 A to 25 A. This makes it possible not only to service these three voltage-differentiated batteries, but also to simultaneously charge several in series or in parallel to each other - e.g. up to four 12-volt batteries. The device is suitable for charging lead-acid batteries from WET MF, GEL, AGM, Ca-Ca batteries.
It diagnoses and detects batteries that have undergone the sulfonation process. The sulfated battery recovery mode is used to restore them. It also has a Floating translate in mode, where the device connects one or more batteries for a long time in full working order.
An extremely valuable quality of the FL 3713D is that it is completely safe from the point of view of possible damage to electronic systems in the car (save function). It is non-sparking and fully protected against false polarity connections, short circuits and surge voltages. It can be connected directly to the vehicle's electrical system without having to be disconnected from the battery.
This is not the case with more common chargers, and there is always the risk of damage to the electronic components, requiring costly and completely redundant repairs - usually at shop or equipment expense. In a nutshell, preventing even one such incident will more than pay off the cost of the charger.
FL-2713DRS A diagram of the battery charging process shows that it has three cycles (phases) or different values of the current-voltage characteristic of the current supplied to the battery. The device initially checks the battery and if it doesn't find a problem, it switches to charging. The first phase operates with constant current and gradually increasing voltage up to 14.8 volts for a 12 volt battery. In the second, the voltage is maintained constant, depending on the state of charge, the power gradually decreases to zero. The third phase (floating) keeps the battery fully charged for a long time.
In desulfurization mode, the voltage applied to the battery increases (up to 16V on a 12V battery) and the process can last from 5 to 48 hours. Finally, you are prompted to indicate whether the restore was successful or not. This process is marked on the diagram with a green dotted line.
The device signals a variety of irregularities and malfunctions, such as reverse polarity cable connections, short circuit between terminals, thermal protection, battery failure and short circuit between plates, incorrectly selected battery capacity, etc.
Location The FL 3713D is located in a workshop or indoors.
Charger and starting station SC 80/900
Another new model in the ELECTRONIC FULL POWER group is the SC 80/900. Again, we have a professional device with the main purpose of charging 12V and 24V lead acid batteries. SC-80-900SSC-80900SIMG_5313SThe main difference between this and the FL 3713D model is that the SC 80/900 can also be used for fast starting engines whose battery cannot do this.
The station is designed for use with WET (Gel and No-Service), GEL, AGM and Ca-Ca batteries.
Its very valuable quality is effective protection against damage to the vehicle’s electronic systems during battery charging (high voltage) or Safe Charge & Boost. To perform this operation, it has a starter button with a cable the length of which allows a person to start the ignition by pressing the button to send a pulse of short circuit current to the starter.
The diagram shows the current-voltage characteristics when charging the battery. The boot process also involves three consecutive cycles. The device has a long battery maintenance mode in a fully charged state.
Low cost chargers
In addition to the highest-end smart devices, DECA also offers high-quality chargers designed for customers where low cost is a determining factor. These are models with optimal price and quality.
In this group there are three models from the MATIC series and five from the MACH series. 
MATIC 116 is an automatic electronically controlled charger designed for 12 V batteries with capacities from 5 to 90 Ah. Suitable for WET, WET MF, AGM, GEL and Ca-Ca batteries. The average charge current is 2.5 A.
There is electronic charge control, LED status indicators and faulty connection to battery poles, current or full charging, short circuit protection and non-polar connection. Its weight is 2 kg.
MACH 114 is a portable conventional charger with an ammeter that measures the instantaneous charging power that can be estimated to charge the battery. Suitable for charging batteries from 15 Ah to 60 Ah and 12 V. There is protection against short circuit and incorrect connection of the clamps to the battery terminals. The average charging current is 2.5A. It is suitable for WET and AGM batteries.
It is detached manually by pulling out the plug. The weight of the device is 1.3 kg.
The difference in prices for these two devices is only 23 leva, so in our opinion, when choosing between these two models, our preference will be given to the MATIC 116.
When working with devices that do not have microprocessor control with full control over charging - batteries and charging current parameters, it is useful to remember the classic rule that the current should not exceed 1/10 of the battery capacity. For example, a 60 AA battery is charged at a maximum current of 6 A for approximately 10-11 hours depending on the discharge rate. Data for batteries ranging from 10Ah to 120Ah are printed in tabular form on the boxes of these two devices. In general, slower charging with less current affects battery life. However, for deeply diluted batteries (below 8.0 V), the charging current should not exceed 1/20 of the battery capacity.
One more thing. Generally, rechargeable batteries are sold from the factory, and the practice is to install them in the vehicle without charging them first. According to Bosch, the minimum voltage of a new battery installed in a vehicle should be 12.5 V. However, service technicians recommend recharging a new rechargeable battery before installing it in the vehicle. Otherwise, their opinion is that it will run at about 80% of its rated power from the start.
For more information and to purchase DECA products, visit the Taev-Galving online store.
The simplest charger for car and motorcycle batteries usually consists of a step-down transformer and a full-wave rectifier connected to its secondary winding. A powerful rheostat is connected in series with the battery to set the required charging current. However, this design turns out to be very cumbersome and excessively energy-intensive, and other methods of regulating the charging current usually complicate it significantly.
In industrial chargers, KU202G thyristors are sometimes used to rectify the charging current and change its value. It should be noted here that the forward voltage on the switched-on thyristor with a high charging current can reach 1.5 V. Because of this, they become very hot, and according to the passport, the temperature of the thyristor body should not exceed +85°C. In such devices, it is necessary to take measures to limit and temperature stabilize the charging current, which leads to their further complexity and cost.
The relatively simple charger described below has wide limits for regulating the charging current - practically from zero to 10 A - and can be used to charge various starter batteries of 12 V batteries.
The device (see diagram) is based on a triac regulator, published in, with an additionally introduced low-power diode bridge VD1 - VD4 and resistors R3 and R5.
After connecting the device to the network at its positive half-cycle (plus on the top wire in the diagram), capacitor C2 begins to charge through resistor R3, diode VD1 and series-connected resistors R1 and R2. With a negative half-cycle of the network, this capacitor is charged through the same resistors R2 and R1, diode VD2 and resistor R5. In both cases, the capacitor is charged to the same voltage, only the charging polarity changes.
As soon as the voltage on the capacitor reaches the ignition threshold of the neon lamp HL1, it lights up and the capacitor is quickly discharged through the lamp and the control electrode of the triac VS1. In this case, the triac opens. At the end of the half-cycle, the triac closes. The described process is repeated in each half-cycle of the network.
It is well known, for example, that controlling a thyristor using a short pulse has the disadvantage that with an inductive or high-resistance active load, the anode current of the device may not have time to reach the value of the holding current during the action of the control pulse. One of the measures to eliminate this drawback is to connect a resistor in parallel with the load.
In the described charger, after turning on the triac VS1, its main current flows not only through the primary winding of transformer T1, but also through one of the resistors - R3 or R5, which, depending on the polarity of the half-cycle of the mains voltage, are alternately connected parallel to the primary winding of the transformer with diodes VD4 and VD3, respectively .
The powerful resistor R6, which is the load of the rectifier VD5, VD6, also serves the same purpose. Resistor R6 also generates discharge current pulses, which are said to extend battery life.
The main unit of the device is transformer T1. It can be made on the basis of a laboratory transformer LATR-2M by insulating its winding (it will be the primary) with three layers of varnish and winding a secondary winding consisting of 80 turns of insulated copper wire with a cross-section of at least 3 mm2, with a tap from the middle. The transformer and rectifier can also be borrowed from the power source published in. When making a transformer yourself, you can use the calculation method outlined in; in this case, they are set by a voltage on the secondary winding of 20 V at a current of 10 A.
Capacitors C1 and C2 - MBM or others for a voltage of at least 400 and 160 V, respectively. Resistors R1 and R2 are SP 1-1 and SPZ-45, respectively. Diodes VD1-VD4 -D226, D226B or KD105B. Neon lamp HL1 - IN-3, IN-ZA; It is very desirable to use a lamp with electrodes of the same design and size - this will ensure the symmetry of the current pulses through the primary winding of the transformer.
KD202A diodes can be replaced with any of this series, as well as with D242, D242A or others with an average direct tone of at least 5 A. The diode is placed on a duralumin heat-sinking plate with a useful surface area. dispersion of at least 120 cm2. The triac should also be mounted on a heat sink plate with approximately half the surface area. Resistor R6 - PEV-10; it can be replaced with five MLT-2 resistors connected in parallel with a resistance of 110 Ohms.
The device is assembled in a durable box made of insulating material (plywood, textolite, etc.). Ventilation holes should be drilled in its upper wall and bottom. The placement of parts in the box is arbitrary. Resistor R1 (“Charging current”) is mounted on the front panel, a small arrow is attached to the handle, and a scale is attached under it. Circuits carrying load current must be made with MGShV brand wire with a cross-section of 2.5...3 mm2.
When setting up the device, first set the required charging current limit (but not more than 10 A) with resistor R2. To do this, connect a battery to the output of the device through a 10 A ammeter, strictly observing the polarity. The resistor R1 is moved to. the highest position according to the diagram, resistor R2 - to the lowest position, and connect the device to the network. By moving the slider of resistor R2, the required value of the maximum charging current is set.
The final operation is to calibrate the scale of resistor R1 in amperes using a standard ammeter.
During the charging process, the current through the battery changes, decreasing by about 20% toward the end. Therefore, before charging, set the initial battery current slightly higher than the nominal value (by about 10%). The end of charging is measured by the density of the electrolyte or with a voltmeter - the voltage of the disconnected battery should be within 13.8...14.2 V.
Instead of resistor R6, you can install a 12 V incandescent lamp with a power of about 10 W, placing it outside the housing. It would indicate the connection of the charger to the battery and at the same time illuminate the workplace.
Literature
1. Energy electronics. Reference manual, ed. V.A. Labuntsova - 1987. pp. 280, 281, 426, 427.
2. Fomin V. Triac power regulator. - Radio, 1981. No. 7, p. 63.
3. Zdrok A. G. Rectifier devices for stabilizing voltage and battery charge - M.: Energoatomizdat, 1988.
4. Gvozditsky G. High-power power supply. - Radio, 1992. No. 4, pp. 43-44..
5. Nikolaev Yu. Homemade power supply? Nothing could be simpler. - Radio, 1992, No. 4. With. 53.54.
