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The simplest charger for a car battery. Making your own car battery charger is easy. Schemes of homemade simple chargers for a car battery

How does the battery charge? Is the circuit of this device complicated or not, in order to make the device with your own hands? Is it fundamentally different from what is used for mobile phones? We will try to answer all the questions posed further in the article.

General information

The battery plays a very important role in the functioning of devices, units and mechanisms that require electricity to operate. So, in vehicles it helps to start the car engine. And in mobile phones, batteries allow us to make calls.

Charging a battery, the circuit and principles of operation of this device are discussed even in a school physics course. But, alas, by the time they graduate, much of this knowledge is forgotten. Therefore, we hasten to remind you that the operation of a battery is based on the principle of a voltage difference (potential) between two plates, which are specially immersed in an electrolyte solution.

The first batteries were copper-zinc. But since then they have improved and modernized significantly.

How does a battery work?

The only visible element of any device is the case. It provides commonality and integrity to the design. It should be noted that the name “battery” can be fully applied to only one battery cell (they are also called banks), and for the same standard 12 V car battery there are only six of them.

Let's return to the body. Strict requirements are put forward to him. So, it should be:

  • resistant to aggressive chemicals;
  • able to withstand significant temperature fluctuations;
  • with good vibration resistance.

All these requirements are met by modern synthetic material - polypropylene. More detailed differences should only be highlighted when working with specific samples.

Principle of operation

We'll look at lead-acid batteries as an example.

When there is a load on the terminal, a chemical reaction begins to occur, which is accompanied by the release of electricity. Over time, the battery will drain. How is it restored? Is there a simple diagram?

Charging a battery is not difficult. It is necessary to carry out the reverse process - electricity is supplied to the terminals, chemical reactions occur again (pure lead is restored), which in the future will allow the use of the battery.

Also, during charging, the density of the electrolyte increases. Thus, the battery restores its original properties. The better the technology and materials used in manufacturing, the more charge/discharge cycles the battery can withstand.

What electrical circuits for charging batteries exist?

The classic device is made of a rectifier and transformer. If we consider the same car batteries with a voltage of 12 V, then the chargers for them have a constant current of approximately 14 V.

Why is this so? This voltage is necessary so that current can flow through a discharged car battery. If he himself has 12 V, then a device of the same power will not be able to help him, which is why they take higher values. But in everything you need to know when to stop: if you increase the voltage too much, it will have a detrimental effect on the service life of the device.

Therefore, if you want to make a device with your own hands, you need to look for suitable charging schemes for car batteries for cars. The same applies to other technology. If a charging circuit is needed, then a 4 V device is needed and no more.

Recovery process

Let's say you have a circuit for charging a battery from a generator, according to which the device was assembled. The battery is connected and the recovery process begins immediately. As it progresses, the devices will grow. The charging current will drop along with it.

When the voltage approaches the maximum possible value, this process practically does not occur at all. This indicates that the device has successfully charged and can be turned off.

It is necessary to ensure that the battery current is only 10% of its capacity. Moreover, it is not recommended to either exceed this indicator or reduce it. So, if you follow the first path, the electrolyte will begin to evaporate, which will significantly affect the maximum capacity and operating time of the battery. On the second path, the necessary processes will not occur at the required intensity, which is why the negative processes will continue, although to a somewhat lesser extent.

Charger

The described device can be purchased or assembled with your own hands. For the second option, we will need electrical circuits for charging batteries. The choice of technology by which it will be made should depend on which batteries are the target. You will need the following components:

  1. (designed on ballast capacitors and a transformer). The higher the indicator can be achieved, the greater the current will be. In general, this should be enough for charging to work. But the reliability of this device is very low. So, if the contacts are broken or something is mixed up, then both the transformer and the capacitors will fail.
  2. Protection in case of connecting the “wrong” poles. To do this, you can construct a relay. So, the conditional connection is based on a diode. If you confuse plus and minus, it will not pass current. And since there is a relay connected to it, it will be de-energized. Moreover, this circuit can be used with a device based on both thyristors and transistors. It must be connected to the break in the wires with which the charging itself is connected to the battery.
  3. Automation that battery charging should have. The circuit in this case must ensure that the device will work only when it is really needed. To do this, resistors change the response threshold of the control diode. 12 V batteries are considered to be fully rated when their voltage is within 12.8 V. Therefore, this indicator is desirable for this circuit.

Conclusion

So we looked at what battery charging is. The circuit of this device can be made on a single board, but it should be noted that this is quite complicated. That's why they are made multi-layered.

As part of the article, various circuit diagrams were presented to your attention, which make it clear how, in fact, batteries are charged. But you need to understand that these are only general images, and more detailed ones, with indications of the chemical reactions taking place, are special for each type of battery.

Battery problems are not that uncommon. To restore functionality, additional charging is necessary, but normal charging costs a lot of money, and it can be done from available “trash.” The most important thing is to find a transformer with the required characteristics, and making a charger for a car battery with your own hands takes just a couple of hours (if you have all the necessary parts).

The battery charging process must follow certain rules. Moreover, the charging process depends on the type of battery. Violations of these rules lead to a decrease in capacity and service life. Therefore, the parameters of a car battery charger are selected for each specific case. This opportunity is provided by a complex charger with adjustable parameters or purchased specifically for this battery. There is a more practical option - making a charger for a car battery with your own hands. To know what parameters should be, a little theory.

Types of battery chargers

Battery charging is the process of restoring used capacity. To do this, a voltage is supplied to the battery terminals that is slightly higher than the operating parameters of the battery. Can be served:

  • D.C. The charging time is at least 10 hours, during this entire time a fixed current is supplied, the voltage varies from 13.8-14.4 V at the beginning of the process to 12.8 V at the very end. With this type, the charge accumulates gradually and lasts longer. The disadvantage of this method is that it is necessary to control the process and turn off the charger in time, since when overcharging the electrolyte may boil, which will significantly reduce its working life.
  • Constant pressure. When charging with a constant voltage, the charger produces a voltage of 14.4 V all the time, and the current varies from large values ​​in the first hours of charging to very small values ​​in the last. Therefore, the battery will not be recharged (unless you leave it for several days). The positive aspect of this method is that the charging time is reduced (90-95% can be reached in 7-8 hours) and the battery being charged can be left unattended. But such an “emergency” charge recovery mode has a bad effect on service life. With frequent use of constant voltage, the battery discharges faster.

In general, if there is no need to rush, it is better to use DC charging. If you need to restore battery functionality in a short time, apply constant voltage. If we talk about what is the best charger to make for a car battery with your own hands, the answer is clear - one that supplies direct current. The schemes will be simple, consisting of accessible elements.

How to determine the necessary parameters when charging with direct current

It has been experimentally established that charge car lead acid batteries(most of them) required current that does not exceed 10% of the battery capacity. If the capacity of the battery being charged is 55 A/h, the maximum charge current will be 5.5 A; with a capacity of 70 A/h - 7 A, etc. In this case, you can set a slightly lower current. The charge will continue, but more slowly. It will accumulate even if the charge current is 0.1 A. It will just take a very long time to restore the capacity.

Since the calculations assume that the charge current is 10%, we obtain a minimum charge time of 10 hours. But this is when the battery is completely discharged, and this should not be allowed. Therefore, the actual charging time depends on the “depth” of the discharge. You can determine the depth of discharge by measuring the voltage on the battery before charging:


To calculate approximate battery charging time, you need to find out the difference between the maximum battery charge (12.8 V) and its current voltage. Multiplying the number by 10 we get the time in hours. For example, the voltage on the battery before charging is 11.9 V. We find the difference: 12.8 V - 11.9 V = 0.8 V. Multiplying this figure by 10, we find that the charging time will be about 8 hours. This is provided that we supply a current that is 10% of the battery capacity.

Charger circuits for car batteries

To charge batteries, a 220 V household network is usually used, which is converted to reduced voltage using a converter.

Simple circuits

The simplest and most effective way is to use a step-down transformer. It is he who lowers 220 V to the required 13-15 V. Such transformers can be found in old tube TVs (TS-180-2), computer power supplies, and found at flea market “ruins”.

But the output of the transformer produces an alternating voltage that must be rectified. They do this using:


The above diagrams also contain fuses (1 A) and measuring instruments. They make it possible to control the charging process. They can be excluded from the circuit, but you will have to periodically use a multimeter to monitor them. With voltage control this is still tolerable (just attach probes to the terminals), but it is difficult to control the current - in this mode the measuring device is connected to an open circuit. That is, you will have to turn off the power every time, put the multimeter in current measurement mode, and turn on the power. disassemble the measuring circuit in reverse order. Therefore, using at least a 10 A ammeter is very desirable.

The disadvantages of these schemes are obvious - there is no way to adjust the charging parameters. That is, when choosing an element base, choose the parameters so that the output current is the same 10% of the capacity of your battery (or a little less). You know the voltage - preferably within 13.2-14.4 V. What to do if the current turns out to be more than desired? Add a resistor to the circuit. It is placed at the positive output of the diode bridge in front of the ammeter. You select the resistance “locally”, focusing on the current; the power of the resistor is larger, since excess charge will be dissipated on them (10-20 W or so).

And one more thing: a do-it-yourself car battery charger made according to these schemes will most likely get very hot. Therefore, it is advisable to add a cooler. It can be inserted into the circuit after the diode bridge.

Adjustable circuits

As already mentioned, the disadvantage of all these circuits is the inability to regulate the current. The only option is to change the resistance. By the way, you can put a variable tuning resistor here. This will be the easiest way out. But manual current adjustment is more reliably implemented in a circuit with two transistors and a trimming resistor.

The charging current is changed by a variable resistor. It is located after the composite transistor VT1-VT2, so a small current flows through it. Therefore, the power can be about 0.5-1 W. Its rating depends on the selected transistors and is selected experimentally (1-4.7 kOhm).

Transformer with a power of 250-500 W, secondary winding 15-17 V. The diode bridge is assembled on diodes with an operating current of 5A and higher.

Transistor VT1 - P210, VT2 is selected from several options: germanium P13 - P17; silicon KT814, KT 816. To remove heat, install on a metal plate or radiator (at least 300 cm2).

Fuses: at the input PR1 - 1 A, at the output PR2 - 5 A. Also in the circuit there are signal lamps - the presence of a voltage of 220 V (HI1) and a charging current (HI2). Here you can install any 24 V lamps (including LEDs).

Video on the topic

DIY car battery charger is a popular topic for car enthusiasts. Transformers are taken from everywhere - from power supplies, microwave ovens... they even wind them themselves. The schemes being implemented are not the most complex. So even without electrical engineering skills you can do it yourself.

Hello uv. reader of the blog “My Radio Amateur Laboratory”.

In today's article we will talk about a long-used, but very useful circuit of a thyristor phase-pulse power regulator, which we will use as a charger for lead-acid batteries.

Let's start with the fact that the charger on the KU202 has a number of advantages:
— Ability to withstand charging current up to 10 amperes
— The charge current is pulsed, which, according to many radio amateurs, helps extend the life of the battery
— The circuit is assembled from non-scarce, inexpensive parts, which makes it very affordable in the price range
- And the last plus is the ease of repetition, which will make it possible to repeat it, both for a beginner in radio engineering, and simply for a car owner who has no knowledge of radio engineering at all, who needs high-quality and simple charging.

Over time, I tried a modified scheme with automatic battery shutdown, I recommend reading it
At one time, I assembled this circuit on my knee in 40 minutes, along with wiring the board and preparing the circuit components. Well, enough stories, let's look at the diagram.

Scheme of a thyristor charger on KU202

List of components used in the circuit
C1 = 0.47-1 µF 63V

R1 = 6.8k - 0.25W
R2 = 300 - 0.25 W
R3 = 3.3k - 0.25W
R4 = 110 - 0.25 W
R5 = 15k - 0.25W
R6 = 50 - 0.25W
R7 = 150 - 2W
FU1 = 10A
VD1 = current 10A, it is advisable to take a bridge with a reserve. Well, at 15-25A and the reverse voltage is not lower than 50V
VD2 = any pulse diode, reverse voltage not lower than 50V
VS1 = KU202, T-160, T-250
VT1 = KT361A, KT3107, KT502
VT2 = KT315A, KT3102, KT503

As mentioned earlier, the circuit is a thyristor phase-pulse power regulator with an electronic charging current regulator.
The thyristor electrode is controlled by a circuit using transistors VT1 and VT2. The control current passes through VD2, which is necessary to protect the circuit from reverse surges in the thyristor current.

Resistor R5 determines the battery charging current, which should be 1/10 of the battery capacity. For example, a battery with a capacity of 55A must be charged with a current of 5.5A. Therefore, it is advisable to place an ammeter at the output in front of the charger terminals to monitor the charging current.

Regarding the power supply, for this circuit we select a transformer with an alternating voltage of 18-22V, preferably in terms of power without reserve, because we use a thyristor in the control. If the voltage is higher, raise R7 to 200 Ohm.

We also do not forget that the diode bridge and the control thyristor must be installed on the radiators through heat-conducting paste. Also, if you use simple diodes such as D242-D245, KD203, remember that they must be isolated from the radiator housing.

We put a fuse at the output for the currents you need; if you do not plan to charge the battery with a current higher than 6A, then a 6.3A fuse will be enough for you.
Also, to protect your battery and charger, I recommend installing mine or, which, in addition to protection against polarity reversal, will protect the charger from connecting dead batteries with a voltage of less than 10.5V.
Well, in principle, we looked at the charger circuit for the KU202.

Printed circuit board of the thyristor charger on KU202

Assembled from Sergei

Good luck with your repetition and I look forward to your questions in the comments.

For safe, high-quality and reliable charging of any types of batteries, I recommend

In order not to miss the latest updates in the workshop, subscribe to updates in In contact with or Odnoklassniki, you can also subscribe to email updates in the column on the right

Don’t want to delve into the routine of radio electronics? I recommend paying attention to the proposals of our Chinese friends. For a very reasonable price you can purchase quite high-quality chargers

A simple charger with an LED charging indicator, green battery is charging, red battery is charged.

There is short circuit protection and reverse polarity protection. Perfect for charging Moto batteries with a capacity of up to 20A/h; a 9A/h battery will charge in 7 hours, 20A/h in 16 hours. The price for this charger is only 403 rubles, free delivery

This type of charger is capable of automatically charging almost any type of 12V car and motorcycle batteries up to 80A/H. It has a unique charging method in three stages: 1. Constant current charging, 2. Constant voltage charging, 3. Drop charging up to 100%.
There are two indicators on the front panel, the first indicates the voltage and charging percentage, the second indicates the charging current.
Quite a high-quality device for home needs, the price is just RUR 781.96, free delivery. At the time of writing these lines number of orders 1392, grade 4.8 out of 5. When ordering, do not forget to indicate Eurofork

Charger for a wide variety of 12-24V battery types with current up to 10A and peak current 12A. Able to charge Helium batteries and SA\SA. The charging technology is the same as the previous one in three stages. The charger is capable of charging both automatically and manually. The panel has an LCD indicator indicating voltage, charging current and charging percentage.

Analysis of more than 11 circuits for making a charger with your own hands at home, new circuits for 2017 and 2018, how to assemble a circuit diagram in an hour.

TEST:

To understand whether you have the necessary information about batteries and chargers for them, you should take a short test:
  1. What are the main reasons why a car battery discharges on the road?

A) The motorist got out of the vehicle and forgot to turn off the headlights.

B) The battery has become too hot due to exposure to sunlight.

  1. Can the battery fail if the car is not used for a long time (sitting in a garage without starting)?

A) If left idle for a long time, the battery will fail.

B) No, the battery will not deteriorate, it will only need to be charged and it will function again.

  1. What current source is used to recharge the battery?

A) There is only one option - a network with a voltage of 220 volts.

B) 180 Volt network.

  1. Is it necessary to remove the battery when connecting a homemade device?

A) It is advisable to remove the battery from its installed location, otherwise there is a risk of damaging the electronics due to high voltage.

B) It is not necessary to remove the battery from its installed location.

  1. If you confuse “minus” and “plus” when connecting a charger, will the battery fail?

A) Yes, if connected incorrectly, the equipment will burn out.

B) The charger simply will not turn on; you will need to move the necessary contacts to the correct places.

Answers:

  1. A) Headlights not turned off when stopping and sub-zero temperatures are the most common causes of battery discharge on the road.
  2. A) The battery fails if it is not recharged for a long time when the car is idle.
  3. A) For recharging, a mains voltage of 220 V is used.
  4. A) It is not advisable to charge the battery with a homemade device if it is not removed from the car.
  5. A) The terminals should not be mixed up, otherwise the homemade device will burn out.

Battery on vehicles require periodic charging. The reasons for the discharge can be different - from headlights that the owner forgot to turn off, to negative temperatures outside in winter. For recharge battery You will need a good charger. This device is available in large varieties in auto parts stores. But if there is no opportunity or desire to purchase, then memory You can do it yourself at home. There are also a large number of schemes - it is advisable to study them all in order to choose the most suitable option.

Definition: A car charger is designed to transmit electric current with a given voltage directly to Battery

Answers to 5 Frequently Asked Questions

  1. Will I need to take any additional measures before charging the battery in my car?– Yes, you will need to clean the terminals, since acid deposits appear on them during operation. Contacts It needs to be cleaned very well so that current flows to the battery without difficulty. Sometimes motorists use grease to treat terminals; this should also be removed.
  2. How to wipe charger terminals?— You can buy a specialized product in a store or prepare it yourself. Water and soda are used as a self-made solution. The components are mixed and stirred. This is an excellent option for treating all surfaces. When the acid comes into contact with soda, a reaction will occur and the motorist will definitely notice it. This area will need to be thoroughly wiped to get rid of all acids. If the terminals were previously treated with grease, it can be removed with any clean rag.
  3. If there are covers on the battery, do they need to be opened before charging?— If there are covers on the body, they must be removed.
  4. Why is it necessary to unscrew the battery caps?— This is necessary so that the gases formed during the charging process can freely exit the case.
  5. Is there a need to pay attention to the electrolyte level in the battery?- This is done without fail. If the level is lower than required, then you need to add distilled water inside the battery. Determining the level is not difficult - the plates must be completely covered with liquid.

It’s also important to know: 3 nuances about operation

The homemade product differs somewhat in its method of operation from the factory version. This is explained by the fact that the purchased unit has built-in functions, helping in work. They are difficult to install on a device assembled at home, and therefore you will have to adhere to several rules when operation.

  1. A self-assembled charger will not turn off when the battery is fully charged. That is why it is necessary to periodically monitor the equipment and connect it to multimeter– for charge control.
  2. You need to be very careful not to confuse “plus” and “minus”, otherwise Charger will burn.
  3. The equipment must be turned off when connecting to charger.

By following these simple rules, you will be able to recharge correctly battery and avoid unpleasant consequences.

Top 3 charger manufacturers

If you don’t have the desire or ability to assemble it yourself memory, then pay attention to the following manufacturers:

  1. Stack.
  2. Sonar.
  3. Hyundai.

How to avoid 2 mistakes when charging a battery

It is necessary to follow the basic rules in order to properly nourish battery by car.

  1. Direct to mains battery connection is prohibited. Chargers are intended for this purpose.
  2. Even device it is made with high quality and from good materials, you will still need to periodically monitor the process charging, so that troubles don't happen.

Following simple rules will ensure reliable operation of self-made equipment. It is much easier to monitor the unit than to spend money on components for repairs.

The simplest battery charger

Scheme of a 100% working 12 volt charger

Look at the picture for the diagram memory at 12 V. The equipment is intended for charging car batteries with a voltage of 14.5 Volts. The maximum current received during charging is 6 A. But the device is also suitable for other batteries - lithium-ion, since the voltage and output current can be adjusted. All the main components for assembling the device can be found on the Aliexpress website.

Required components:

  1. dc-dc buck converter.
  2. Ammeter.
  3. Diode bridge KVRS 5010.
  4. Hubs 2200 uF at 50 volts.
  5. transformer TS 180-2.
  6. Circuit breakers.
  7. Plug for connecting to the network.
  8. "Crocodiles" for connecting terminals.
  9. Radiator for diode bridge.

Transformer any one can be used at your own discretion. The main thing is that its power is not lower than 150 W (with a charging current of 6 A). It is necessary to install thick and short wires on the equipment. The diode bridge is fixed on a large radiator.

Look at the picture of the charger circuit Dawn 2. It is compiled according to the original Memory If you master this scheme, you will be able to independently create a high-quality copy that is no different from the original sample. Structurally, the device is a separate unit, closed with a housing to protect the electronics from moisture and exposure to bad weather conditions. It is necessary to connect a transformer and thyristors on the radiators to the base of the case. You will need a board that will stabilize the current charge and control the thyristors and terminals.

1 smart memory circuit

Look at the picture for a circuit diagram of a smart charger. The device is necessary for connection to lead-acid batteries with a capacity of 45 amperes per hour or more. This type of device is connected not only to batteries that are used daily, but also to those on duty or in reserve. This is a fairly budget version of the equipment. It does not provide indicator, and you can buy the cheapest microcontroller.

If you have the necessary experience, then you can assemble the transformer yourself. There is also no need to install audible warning signals - if battery connects incorrectly, the discharge lamp will light up to indicate an error. The equipment must be equipped with a switching power supply of 12 volts - 10 amperes.

1 industrial memory circuit


Look at the industrial diagram charger from Bars 8A equipment. Transformers are used with one 16-volt power winding, several vd-7 and vd-8 diodes are added. This is necessary in order to provide a bridge rectifier circuit from one winding.

1 inverter device diagram

Look at the picture for a diagram of an inverter charger. This device discharges the battery to 10.5 Volts before charging. The current is used with a value of C/20: “C” indicates the capacity of the installed battery. After that process the voltage rises to 14.5 Volts using a discharge-charge cycle. The ratio of charge and discharge is ten to one.

1 electrical circuit charger electronics

1 powerful memory circuit


Look at the picture at the diagram of a powerful charger for a car battery. The device is used for acidic battery, having high capacity. The device easily charges a car battery with a capacity of 120 A. The output voltage of the device is self-regulated. It ranges from 0 to 24 volts. Scheme It is notable for the fact that it has few components installed, but it does not require additional settings during operation.

Many could already see the Soviet Charger. It looks like a small metal box and may seem quite unreliable. But this is not true at all. The main difference between the Soviet model and modern models is reliability. The equipment has structural capacity. In the event that to the old device connect the electronic controller, then charger it will be possible to revive. But if you no longer have one at hand, but there is a desire to assemble it, you need to study the diagram.

To the features their equipment includes a powerful transformer and rectifier, with the help of which it is possible to quickly charge even a very discharged battery. Many modern devices will not be able to reproduce this effect.

Electron 3M

In an hour: 2 DIY charging concepts

Simple circuits

1 the simplest scheme for an automatic charger for a car battery

Under normal operating conditions, the vehicle's electrical system is self-sufficient. We are talking about energy supply - a combination of a generator, a voltage regulator, and a battery works synchronously and ensures uninterrupted power supply to all systems.

This is in theory. In practice, car owners make amendments to this harmonious system. Or the equipment refuses to work in accordance with the established parameters.

For example:

  1. Operating a battery that has exhausted its service life. The battery does not hold a charge
  2. Irregular trips. Prolonged downtime of the car (especially during hibernation) leads to self-discharge of the battery
  3. The car is used for short trips, with frequent stopping and starting of the engine. The battery simply does not have time to recharge
  4. Connecting additional equipment increases the load on the battery. Often leads to increased self-discharge current when the engine is turned off
  5. Extremely low temperature accelerates self-discharge
  6. A faulty fuel system leads to increased load: the car does not start immediately, you have to turn the starter for a long time
  7. A faulty generator or voltage regulator prevents the battery from charging properly. This problem includes worn power wires and poor contact in the charging circuit.
  8. And finally, you forgot to turn off the headlights, lights or music in the car. To completely discharge the battery overnight in the garage, sometimes it is enough to close the door loosely. Interior lighting consumes quite a lot of energy.

Any of the following reasons leads to an unpleasant situation: you need to drive, but the battery is unable to crank the starter. The problem is solved by external recharge: that is, a charger.

The tab contains four proven and reliable car charger circuits from simple to the most complex. Choose any one and it will work.

A simple 12V charger circuit.

Charger with adjustable charging current.

Adjustment from 0 to 10A is carried out by changing the opening delay of the SCR.

Circuit diagram of a battery charger with self-shutdown after charging.

For charging batteries with a capacity of 45 amps.

Scheme of a smart charger that will warn about incorrect connection.

It is absolutely easy to assemble it with your own hands. An example of a charger made from an uninterruptible power supply.