Charger circuit with automatic shutdown. Automatic car charger. Bosch C3 - a simple model for passenger cars

A very simple charger circuit that uses only one transistor to detect the voltage to automatically disconnect the battery from the mains when it is fully charged.

Description of the car battery charger circuit

In the figure, we see a simple circuit where one transistor is turned on in its standard mode of operation.

The principle of operation of the circuit can be understood from the following points:

1. The battery charge is considered complete when the voltage at its terminals reaches 13.5 - 14 volts.
2. The shutdown threshold (13.5 - 14 volts) is set by the trimming resistor R2 with a fully charged battery connected. When the voltage at the battery terminals is about 14 volts, transistor T1 will turn on the relay and the charge circuit will be broken.

This automatic car charger is not only easy to make, but also smart enough to take care of the battery and charge it very efficiently.

Parts list:

• R1 \u003d 4.7 kOhm;
• R2 = 10K trim;
• T1 = ;
• Relay = 12V, 400 Ohm, SPDT;
• TR1 = secondary voltage 14 V, current 1/10 of the battery capacity;
• Diode bridge = for a current equal to the rated current of the transformer;
• Diodes D2 and D3 = 1N4007;
• C1 = 100uF/25V.

From the site administrator

The article is theoretical, in practice I didn't make this diagram.. I recommend to pay attention to such important points:

1. The battery is disconnected from the charger when the charging voltage reaches 13.5 - 14 volts. You need to set this voltage threshold (trimming resistor R2) with a fully charged battery connected. If there is no charged battery, then you need to set R2 to the lower (according to the diagram) position, that is, “put” the base of the transistor on the ground. Then connect the battery and plug in the charger. Next, you need to constantly monitor the charging voltage, when it reaches 13.5 - 14 volts, you need to set R2 to such a position that the relay opens its contacts.
2. When a voltage of 13.5 - 14 volts is reached at the battery terminals, the device is disconnected from the battery. Further, when the voltage drops to 11.4 volts, charging resumes again. The original article says that such hysteresis is provided by diodes in the emitter of the transistor.
3. In the scheme no charging current limit, therefore, I recommend using a transformer with a power of at least 150 watts in the manufacture of this charger, the secondary winding of which is designed for a current of at least 10 amperes. The diode bridge must also correspond to the specified current.

A car's battery sometimes needs to be recharged to keep it running. This is true in case of sudden temperature changes, increased consumption load in the on-board network (powerful audio systems, heated seats, etc.) or when using a car for short distance trips, when the battery does not have time to restore its volume from a regular generator.

Our review presents the best chargers available on the domestic market. The distribution of models in the rating is based on the characteristics of the devices, user reviews and the estimated opinions of experts in the field of automotive electronics.

The best automatic chargers

A feature of this category of devices is the automatic adjustment of the current, the value of which changes in accordance with the level of battery charge. This method prevents the "boiling" of the electrolyte and ensures a long battery life.

3 ORION PW150

Best price
Country Russia
Average price: 1225 rubles.
Rating (2019): 4.5

The simplest and at the same time practical charger that works in automatic mode with lead-acid batteries. This is a model that is very different from competitors in the rating: the ascetic front panel contains only two indicators - no switches, no regulator knobs and a display that notifies the amount of charging current. There is a battery charge control light and, in essence, a process activity diode.

As for charging, the ORION PW150 is not able to pull out a battery discharged to zero, but can only help survive to those who are in actual "death". On this, his talents are exhausted, but simplicity still gains a modicum of popularity among users. The owners of the ORION PW150 charger, leaving reviews, generally evaluate this device on the positive side. Using it is extremely simple, you don’t need to control anything - the battery can be connected to it, even for a whole week, and at the same time you should not be afraid of overcharging and damaging the battery. Many motorists managed to extend the operational life of the battery for another season with its help. True, for this it was always necessary to put the battery on recharging at sub-zero temperatures.

2 Auto electrician T-1001AR

Prevents battery sulfation
Country Russia
Average price: 3300 rubles.
Rating (2019): 4.7

The charger supports a maximum current of 9 A and can recharge batteries up to 110 Ah for cars (12 V) or motorcycles (6 V). The reverse current keeps the plates from premature destruction and contributes to a more efficient recovery of the working capacity.

The owners, leaving reviews, reasonably consider the T-1001AR to be the best charger. The device can work with gel batteries and batteries with AGM technology. Regular use prevents sulfation of the battery plates (the most common cause of battery failure) and reduces the self-discharge current. In addition to displaying the battery status on the display, using the device, you can also check the operability of the generator and the relay-regulator.

1 QUATTRO ELEMENTI i-Charge 10

Good technical equipment
Country: Italy
Average price: 3990 rubles.
Rating (2019): 4.9

Not too compact expensive device for automatic recharging of high-end car batteries. Easily copes with the gradual "refueling" of batteries with a capacity of 100 Ah. The beginning of the charging process takes place at a nominal current value of 6.5 A. Gradually, processing the received data from the battery status terminals, the device itself selects the mode that is optimal for these conditions, either increasing or decreasing the ammeter readings.

Another important factor is the presence of a warning system about a malfunction, due to which it becomes much easier to control the work process. The owners, leaving their reviews, indicate in them that with the help of QUATTRO ELEMENTI i-Charge 10 they were able to extend the life of the regular battery and save themselves from problems with starting the engine in cold weather. The only thing missing from this device (according to the owners) is a forced charge system that allows you to "pick up dead" batteries.

The best manual chargers

Penetrating chargers for resuscitation of "tightly" dead batteries. They are distinguished by instantaneous and stable transmission of current of a certain strength to the terminals, which is perceived by the battery in small volumes. Gradually, the battery "comes to life" and begins to receive current in full portions.

The main disadvantage of such chargers is the need for constant monitoring - from an excess of energy, the electrolyte in the battery begins to boil, which often leads to an explosion of the battery itself and entails damage to property and health. They cost an order of magnitude cheaper than automatic counterparts, however, for security reasons (if there is no time to monitor the charge process), it is better to resort to buying an automatic device.

4 KOLNER KBCH 4

Best price
Country: Russia (produced in China)
Average price: 880 rubles.
Rating (2019): 4.5

A fairly simple, and yet reliable start-charger will help, if necessary, quickly start the car engine - the main thing is that there is a 220 V network or an alternator nearby. Actually, this instance does not demonstrate anything new - it meets the standard requirements for recharging 12-volt batteries, and does it quite conscientiously. Unlike many much more serious models, KOLNER KBCH 4 has an additional short circuit protection block, so erroneous connection of the terminals will not be fatal for the battery.

The charge is indicated by means of distinguishable LEDs, both at night and during the daytime. The only serious inconvenience of the device is the need for periodic monitoring - from excessive current saturation, the electrolyte can simply boil. However, user reviews positively assess the convenient case and the capabilities of the device. In addition, the “starter” KOLNER has one of the most affordable prices on the market, which attracts its new owners.

3 Sonar UZP-210

Optimum combination of performance
Country Russia
Average price: 4050 rubles.
Rating (2019): 4.9

A modern system with a switching voltage converter, dressed in an echo case from the 90s. The model is so practical that the first advantage can be called simple and clear manual control. The rest of the manipulations are simply superfluous: Sonar UZP-210 does everything by itself, in automatic mode. This is a clear example of combining two conceptually different ways of managing, which gives excellent results. There are two charging modes - with a maximum of 12 A or 6 A for different types of batteries. Charging proceeds according to the classic scenario of the automatic method: fast recharging, equalization of the current supply to the standard value, as the battery is saturated, the transition to buffer mode and voltage stabilization at the saturation level.

Advantages:

• impressive short-term starting current (200 A for one or two seconds);
• compactness;
• automatic charging with manual settings.

Flaws:

• not detected.

2 ZPU 135

The best transformer charger
Country Russia
Average price: 4200 rubles.
Rating (2019): 4.9

The most powerful starting-charging transformer device with a manual type of control, the potential of which can be enough to “breathe life” into an empty capacious battery. The maximum charge current reaches an impressive figure of 13 A, and the starting current, and even more so, is a one-time release of 140 A (for 10-15 seconds, for a simple estimate, it is able to instantly “boil” the electrolyte even in a battery with a capacity of 140 Ah (and 12 -ti, and 24-volt). Only a small number of consumers prefer to resort to home use of such a device - it has become much more widespread in the circles of auto repair shops, services and transport shops of private and public enterprises. The only drawback of the system is the lack of protection against the occurrence of a short circuits - when fixing the terminals, you should be especially careful.

Advantages:

• high rated power for start-up and normal charging;
• elementary management;
• attractive cost.

Flaws:

• the probability of a short circuit of the terminals and failure of the device.

1 FUBAG COLD START 300/12

The most efficient device
Country: Germany
Average price: 6050 rubles.
Rating (2019): 5.0

FUBAG COLD START 300/12 became the leader among the starters and chargers included in our rating. Despite the microprocessor automatic control of the device, it ended up in this category due to the ability to quickly reanimate a car battery and ensure reliable engine start in harsh winter conditions and with an acute shortage of time.

Owner reviews emphasize the ability to restore completely “dead” batteries after deep discharge using FUBAG COLD START. As a result of using the charger, the prospect of the battery being sent for recycling can be postponed for at least one more calendar season, and the purchase of a new power source for the car will not be necessary at all.

The best microprocessor-controlled chargers

Modern high-tech chargers, in addition to preventive recharging of batteries, allow you to restore deeply discharged batteries of various types of design. By adjusting the current and voltage according to a given algorithm, these devices increase the battery life, which confirms their high efficiency.

3 SMART-POWER SP-25N Professional

High quality device
Country: Philippines
Average price: 9990 rubles.
Rating (2019): 4.5

One of the representatives of a small cohort of chargers that work not only with 12-volt, but also with 24-volt batteries. Despite its unsightly dimensions, this is a fairly powerful device capable of charging electrolyte batteries on an industrial scale. If we follow the trend of purchases, it becomes clear that about 20% of consumers buy the device for personal use, while the rest are representatives of service centers, car repair and maintenance stations. However, the high build quality and the covered operating range significantly add to the price of the SMART-POWER SP-25N Professional, due to which budget users are eliminated already at the stage of a cursory choice.

Nevertheless, the successful owners are satisfied with the performance of the charger. Particular attention in the reviews is paid to the moisture resistance of the case and the presence of an information display that clearly reflects the ongoing charging processes. The build quality and reliability of component parts are highly appreciated - the device can work almost non-stop, taking short breaks only to connect to another battery. Battery recovery modes after deep discharge fully justify the cost of this equipment.

2 RedHotDot VOLTA G-260

Long service life
Country: Germany (made in Italy)
Average price: 14900 rubles.
Rating (2019): 4.8

The control panel of this charger is quite simple and clear, so it is almost impossible to make a mistake when choosing a battery mode. The device is made of high quality parts and has an excellent assembly, which ultimately determines its professional level of performance and durability.

Users using the RedHotDot VOLTA G-260 can service not only ordinary car batteries. It can charge motorcycle (6 V) batteries, as well as parallel-connected pairs of batteries (24 V) used in some luxury cars and heavy vehicles. In the reviews, the model is characterized positively - the owners like the full automation of the process, security systems that work in emergency situations (heating of the network, short circuit) and the presence of an operating mode for restoring the battery after a deep discharge.

1 Daewoo DW 800

The best ratio of price and quality
Country: South Korea
Average price: 4480 rubles.
Rating (2019): 5.0

One of the best microprocessor controlled chargers. Provides diagnostics of the state of the connected battery, independently selects the current strength and the magnitude of the supplied voltage, depending on the selected mode (smooth, express, winter and auto).

It has the most effective protection systems for short circuit, overheating of wiring and non-observance of polarity. In the reviews, the owners positively evaluate the presence and information content of the LCD display, diagnostic and desulfation modes. In addition, the device can work with five different types of batteries and, if used regularly to recharge a car battery, allows you to increase its life. In some cases, more than twice the normal battery life is known.

How to choose a good charger

To select the ideal charger in terms of performance and durability, there are a number of important criteria to consider:

1. Appointment. Devices are divided into three types:

• launchers, whose task is a one-time resuscitation of the battery to obtain a momentary result;
• chargers designed for long-term, but complete recharge of the battery;
• start-charging - a combination of the first two types of devices, serving as a universal device.

The choice depends on your personal preferences.

1. Charging method. This category has only two methods: auto, in which the voltage is adjusted by the device as the battery charge increases, and classic (manual), requiring periodic monitoring of the process by the user.
2. Supported voltage modes. A parameter that determines the typology of rechargeable batteries. So, some devices are designed to charge simple 6-volt batteries that are on motor vehicles, while others feed powerful 24-volt or more average 12-volt batteries.
3. Availability of additional functions. Some manufacturers tend to add distinctive features to their products, be it original LEDs, battery power modes (Boost, pulse charging, etc.) or equipping the device with a drive that can remember the results of charging sessions.

Charger with automatic shutdown (hereinafter - UZ-A device) is designed to charge 6 and 12-volt starter batteries installed on motorcycles and personal cars.

Before using the UZ-A device, it is necessary to study this manual, as well as the rules for the care and operation of the battery.

The UZ-A device is designed for operation in temperate climates at ambient temperatures from minus 10 °C to plus 40 °C and relative humidity up to 98% at 25 °C.

This device produces a charge in the presence of a voltage on the battery of at least 4 volts.

Technical details

• Mains voltage - 220 ± 22 V;
• Network frequency - 50 ± 05 Hz;
• Charge current setting range - 0.5 - 7.5 A;
• Automatic disconnection from the battery after - 10.5 ± 1 h;
• Power consumption, no more than -145 W;
• AC voltage for powering a portable car lamp 36 ± 2 V.

On the front panel are:

1. LED "NETWORK", signaling the inclusion of the device;
2. current indicator to control the charge current;
3. adjustment knob for setting the charge current;
4. LED signaling the end of the charge cycle.

A radiator for cooling the rectifier is placed on the back wall of the charger.

A socket for powering a portable lamp 36 V (electric soldering iron, etc.) and a fuse are installed on the radiator.

In the lower part of the case, the device has a niche in which the power cord and cables with "+" and "-" terminals are placed to connect the charger to the corresponding battery terminals.

Note. The principle of operation of the charger circuit with automatic shutdown is almost the same as the operation of the automatic charger circuit "Electronics" described above.

Rice. 1. The appearance of the charger with automatic shutdown "Electronics".

Checking the performance of the charger

In the conditions of sale of the charger in the store in the absence of a battery, as well as at the consumer's to check the performance of the charger, it is allowed to briefly use dry cell batteries with a total voltage of at least 4 V instead of the battery (it is most convenient to use a battery with a voltage of 4.5 V, it is allowed to use series-connected elements of 1.5 V each - at least 3 elements).

Perform the check as follows:

1. Set the adjustment knob to the leftmost position.
2. Connect the terminals of the charger to the battery terminals, observing the polarity: the “+” terminal of the device to the “+” of the battery, and the “-” terminal of the device to the “-” of the battery.
3. Connect the charger to the 220 V alternating current network, while the "NETWORK" LED on the front panel of the device will light up and, depending on the state of the electronic circuit, the LED may light up.
4. Turn the adjustment knob clockwise to make sure that the current changes (the current will gradually increase). This is a criterion for the health of the device. Note. In order to avoid premature failure of the test battery, it is recommended to test the current for no more than 5 + 10 seconds and set the current value to no more than 3 5 A.
5. After checking, remove the adjustment knob (counterclockwise until there is no indication of the charging current. Disconnect the charger from the mains and from the battery.

Safety Requirements

When operating the UZ-A device, it is not allowed:

• replacement of the fuse, as well as repair of the device in the on state;
• mechanical damage to the insulation of the power cord, wires of the output terminals, as well as the ingress of a chemically active medium (acids, oils, gasoline, etc.) onto it.

In the process of charging, the temperature of the device body is allowed to exceed the ambient temperature by no more than 60 °C.

Rice. 2. Schematic diagram of the charger with automatic shutdown Electronics.

Rice. 3. The circuit board of the charger with automatic shutdown "Electronics".

Rice. 4. The circuit board of the charger with automatic shutdown "Electronics.

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

It's in theory. In practice, car owners amend this orderly system. Or the equipment refuses to work in accordance with the set parameters.

For example:

1. Operating a battery that has reached its end of life. The battery does not hold a charge
2. Irregular travel. A long idle time of the car (especially during the "winter hibernation") leads to battery self-discharge
3. The car is used in the mode of short trips, with frequent muffling and starting the engine. The battery just can't get recharged.
4. Connecting additional equipment increases the load on the battery. Often leads to increased self-discharge current when the engine is 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 alternator or voltage regulator prevents the battery from charging normally. This problem includes frayed power wires and poor contact in the charge circuit.
8. And finally, you forgot to turn off the headlights, dimensions or music in the car. To completely discharge the battery overnight in the garage, sometimes it is enough to loosely close the door. Interior lighting consumes a lot of energy.

Any of the following causes an unpleasant situation: you have to go, and the battery is unable to crank the starter. The problem is solved by external recharge: that is, a charger.

In the tab there are four proven and reliable car charger circuits from the simplest to the most complex. Choose any 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 delay in opening the trinistor.

Diagram of a battery charger with self-shutoff after charging.

For charging batteries with a capacity of 45 amperes.

The scheme of a smart charger that will warn of incorrect connection.

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

This is a very simple set-top box to your existing charger. Which will control the voltage of the battery charge and, when the set level is reached, disconnect it from the charger, thereby preventing the battery from overcharging.
This device has absolutely no hard-to-find parts. The whole circuit is built on just one transistor. It has LED indicators showing the status: charging or battery is charged.

Who will benefit from this device?

Such a device will definitely come in handy for motorists. Those who have a non-automatic charger. This device will turn your ordinary charger into a fully automatic charger. You no longer have to constantly monitor the charging of your battery. All you need to do is put the battery on charge, and it will turn off automatically only after it is fully charged.

Diagram of an automatic charger

Here is the circuit diagram of the machine itself. In fact, this is a threshold relay that is triggered when a certain voltage is exceeded. The threshold is set by a variable resistor R2. For a fully charged car battery, it is usually -14.4 V.
You can download the diagram here -

Printed circuit board

How to make a printed circuit board is up to you. It is not complicated and therefore it can easily be thrown on a breadboard. Well, or you can get confused and make it on textolite with etching.

Setting

If all the details are serviceable, the setting of the machine comes down only to setting the threshold voltage with resistor R2. To do this, we connect the circuit to the charger, but do not connect the battery yet. We translate the resistor R2 to the lowest position according to the scheme. We set the output voltage on the charger to 14.4 V. Then slowly rotate the variable resistor until the relay works. Everything is set.
Let's play with the voltage to make sure that the set-top box reliably works at 14.4 V. After that, your automatic charger is ready to go.
In this video you can see in detail the process of the entire assembly, adjustment and testing in operation.