This Charger i made for charging car batteries, output voltage 14.5 volts, maximum charging current 6 A. But it can also charge other batteries, such as lithium-ion, since the output voltage and output current can be adjusted within wide limits. The main components of the charger were purchased on the Aliexpress website.
These are the components:
Still need electrolytic capacitor 2200 uF at 50 V, a transformer for the TS-180-2 charger (see how to solder the TS-180-2 transformer), wires, a power plug, fuses, a radiator for a diode bridge, crocodiles. The transformer can be used with another one, with a capacity of at least 150 W (for a charging current of 6 A), the secondary winding must be rated for a current of 10 A and produce a voltage of 15 - 20 volts. Diode bridge can be recruited from individual diodes designed for a current of at least 10A, for example, D242A.
The wires in the charger should be thick and short. The diode bridge needs to be fixed to a large radiator. It is necessary to increase the heatsinks of the DC-DC converter, or use a fan for cooling.
Assembling the charger
Connect the cord with mains plug and a fuse to the primary winding of the ТС-180-2 transformer, install the diode bridge on the radiator, connect the diode bridge and the secondary winding of the transformer. Solder a capacitor to the positive and negative terminals of the diode bridge.
Connect the transformer to a 220 volt network and measure the voltages with a multimeter. I got the following results:
- AC voltage at the terminals of the secondary winding 14.3 volts (network voltage 228 volts).
- DC voltage after diode bridge and capacitor 18.4 volts (no load).
Referring to the diagram, connect a buck converter and a voltammeter to the DC-DC diode bridge.
Setting the output voltage and charging current
The DC-DC converter board has two trimming resistors, one allows you to set the maximum output voltage, the other can set the maximum charging current.
Connect the charger to the mains (nothing is connected to the output wires), the indicator will show the voltage at the output of the device, and the current equal to zero... Set the voltage potentiometer to 5 volts. Close the output wires together, set the current with the current potentiometer short circuit 6 A. Then remove the short circuit by disconnecting the output wires and using the voltage potentiometer, set the output to 14.5 volts.
This charger is not afraid of a short circuit at the output, but if the polarity is reversed, it may fail. To protect against polarity reversal, a powerful Schottky diode can be installed in the break of the positive wire going to the battery. Such diodes have a low voltage drop at direct inclusion... With this protection, if the polarity is reversed when connecting the battery, no current will flow. True, this diode will need to be installed on a radiator, since a large current will flow through it when charging.
Suitable diode assemblies used in computer power supplies. In such an assembly there are two Schottky diodes with a common cathode, they will need to be paralleled. For our charger, diodes with a current of at least 15 A.
It should be borne in mind that in such assemblies, the cathode is connected to the case, therefore, these diodes must be installed on the radiator through an insulating gasket.
It is necessary to adjust the upper voltage limit again, taking into account the voltage drop across the protection diodes. To do this, use the voltage potentiometer on the DC-DC converter board to set 14.5 volts measured with a multimeter directly at the output terminals of the charger.
How to charge the battery
Wipe the battery with a cloth soaked in baking soda solution, then dry. Unscrew the plugs and check the electrolyte level, if necessary add distilled water. The plugs must be turned out during charging. Debris and dirt must not get inside the battery. The room in which the battery is being charged must be well ventilated.
Connect the battery to the charger and turn on the device to the mains. During charging, the voltage will gradually rise to 14.5 volts, the current will decrease over time. The battery can be conditionally considered charged when the charging current drops to 0.6 - 0.7 A.
There are a lot of people in Lately ask to write an article or shoot a video review about the most simple charger for car battery... I decided to write an article and shoot a video so that there are no questions related to charging car batteries.
At the same time, users are asked to bring the design of the simple option... Of course on hastily you can make a charger for a car, but without galvanic isolation from a 220 Volt network, it is very dangerous and it is not advisable to always charge the battery with such a charge (we will have a quick look at the general collection of chargers in a hurry in the next article).
The cheapest power supply is definitely an electronic transformer. Now in stores such a block for 60-80 watts costs only one dollar. 60 watts is quite a lot of power, this turns out to be somewhere around 4-5 amperes of current at a voltage of 14 volts - it is quite possible to charge the battery!
The electronic transformer has no protection, so do not short the output wires, otherwise it will be bad (in best case cotton, at worst - shrapnel injury with serious consequences).
- The second drawback is that the unit does not turn on without an output load.
- The third drawback is the variable output voltage - 15 kHz
- The fourth drawback is the output voltage of 8-10 volts, which is not enough to charge the car battery.
You can fix these jambs in half an hour. To begin with, we will add short-circuit protection and a system for turning on the unit without an output load, and also increase the output voltage to 14 Volts.
We need a 3-10 Ohm wirewound resistor, the higher the rating, the lower the protection operation current, I advise you to use a 3-6 Ohm resistor.
We take a 0.8mm wire, fold it into 4 cores and wind a new winding on the transformer frame. The winding consists of 12-14 turns.
After that, we wind a separate winding in the same direction - only 3 turns with a 0.8mm wire (the wire is not critical -0.4-0.8mm).
We look at the transformer board and find the OS transformer ( Feedback). It is in the form of a small ring and consists of 3 independent windings - 2 of them are the base windings of transistors, 3 turns each winding. The third winding - the OS winding, consists of only one turn. We solder this winding and replace it with a jumper. Then, on the same ring, we wind 2 turns of 0.8mm wire and connect the OS resistor in series, we make the connection according to the photo.
Everything is ready - such a revision implemented protection against short-circuit at the output, increased the output voltage of the unit and the unit now turns on without an output load. It remains to add a diode rectifier and a smoothing capacitor after the rectifier. It is advisable to assemble a full-fledged diode bridge from KD213 diodes, but of course, any other pulse diodes with a current of at least 4-5 A, preferably 10 Amperes or more, can be used.
Electrolyte for 1000 uF (470-2200 uF can be, but you can remove it altogether)
The output voltage is about 14.5 volts. We connect the unit to a 220 Volt network and measure the voltage. Then we connect the battery for charging BUT! necessarily through an ammeter. If the current is more than 4 Amperes, then in series to one of the power buses (plus or minus) we connect a 5-10 watt resistor with a resistance of 0.5-2.2 Ohm - the resistor must be selected until we get a charge current of about 4A (3, 5-4A). This is necessary so that the unit does not overload and fail.
There are some safety tips at the end.
Always connect the electronic transformer to a 220 Volt network in series through a 220 Volt 40-100 watt incandescent lamp, so explosions can be avoided if improperly installed.
Do not short circuit the output wires electronic transformer... During the tests, do not touch the device board when the transformer is connected to a 220 Volt network. Be extremely careful during trials to avoid tragic consequences.
In the video clip he told in detail about the alteration, if anyone is too lazy to read the article, but still interesting, then watch the video - until we meet again on the pages of the site - AKA KASYAN
Homemade charging can come in handy if your battery runs out and you don't have a normal electrical appliance at hand. Making it yourself is quite simple, you just need to have a few basic elements of the chain. Next, we will take a closer look at the homemade device, as well as instructions on how to make a do-it-yourself battery charger.
Homemade device
So, to assemble the charger, we need the following elements:
- Power transformer. A part from an old TV is ideal. Usually transformers TS-180-2 are installed, so we will consider it in the article.
- Glass fiber plate.
- D242A diodes - 4 pcs., You can use products of other markings, but they must be rated for a current of more than 10 A.
- Radiators for a diode - 4 pcs., An area of 25 cm 2 (and preferably 32 cm 2).
- Dismountable electrical plug.
- Copper wires with a cross section of not less than 2.5 mm 2
- Fuse 10 A and 0.5 A.
- Soldering iron.
Having prepared all the materials, you can proceed to the very process of assembling the car charger.
Assembly technology
To make a do-it-yourself car battery charger, you must follow the step-by-step instructions:
- Create a schema homemade charging for battery. In our case, it will look like this:
- We remove the secondary windings of the TV transformer (the primary must be left) and connect them in series in the circuit. As a result, they should get 12.8 V at the output, because the voltages of the secondary windings are 6.4 V and 4.7 V.
- Via copper wire we connect pins 9 and 9 'together.
- On a fiberglass plate, we assemble a diode bridge from diodes and radiators (as shown in the photo).
- Conclusions 10 and 10 'are connected to the diode bridge.
- We connect in series the primary windings of the TS-180-2 television transformer.
- Install a jumper between pins 1 and 1 '.
- We attach the power cord with a plug to pins 2 and 2 'using a soldering iron.
- We connect a 0.5 A fuse to the primary circuit, and a 10-amp fuse, respectively, to the secondary.
- We limit the charging current by connecting a 12-volt light bulb to the gap neutral conductor, in series with the battery itself. The power should vary between 21-60 watts.
An illustrative example of a finished product
Operating rules
The disadvantage of a homemade 12V battery charger is that after full charge The battery does not automatically turn off the device. That is why you will have to periodically glance at the scoreboard in order to turn it off in time. Another important nuance- it is strictly forbidden to check the charger "for a spark".
Among additional measures precautions should be highlighted as follows:
- when connecting the terminals, make sure not to confuse "+" and "-", otherwise a simple homemade battery charger will fail;
- connection to the terminals must be carried out only in the off position;
- the multimeter must have a scale of more than 10 A.
Long-term use of the car leads to the fact that the generator stops charging the battery. As a result, the car will no longer start. To revive the car you need a charger. In addition, lead acid batteries have increased sensitivity to temperatures. Therefore, problems may arise with their work if the temperature outside the window is subzero.
A charger for a car is not particularly complicated. To collect it, you do not need to have any highly specialized knowledge, perseverance and ingenuity are enough. Of course, you need certain parts, but they can be easily purchased on the radio market for almost nothing.
Varieties of car chargers
Science does not stand still. Technology is developing at an incredible speed, it is not surprising that transformer chargers are gradually disappearing from the market, and pulsed and automatic chargers are replacing them.
The impulse car charger is compact in size. His easy to use, and unlike transformer type apparatus of this class provide a full battery charge... The charging process takes place in two stages: first, when constant voltage, then at current. The design consists of the same type of circuits.
The automatic car charger is extremely easy to use. In fact, this is a multifunctional diagnostic center, which is extremely difficult to assemble on your own.
The most advanced devices of this class will notify you with a signal when wrong connection poles. Moreover, the power supply will not even start. The diagnostic functions of the device cannot be ignored. He is able to measure the capacity of the battery and even the charge level.
V electrical diagrams there is a timer. Therefore, the automatic car charger allows charging different types:
- full,
- fast,
- restorative.
As soon as the automatic car charger finishes charging, a sound signal, and the supply of current will automatically stop.
Three ways to make your own car charger
How to charge from a computer unit
Old computers are not uncommon. Someone leaves them out of a sense of nostalgia, while others expect to use serviceable components somewhere. If you don't have an old desktop computer at home, that's okay. Second-hand the power supply unit can be purchased for 200-300 rubles.
Power supplies from stationary computers ideal for making any chargers. As a controller, a TL494 microcircuit or a similar KA7500 is used here.
The power supply for the charger must be 150 W or more. All wires from sources -5, -12, +5, +12 V are soldered. Also done with resistor R1. It needs to be replaced with a trimmer. In this case, the value of the latter should be 27 ohms.
The scheme of operation of a charger for a car from a power supply is extremely simple. The voltage from the bus marked in +12 V is transmitted to the upper terminal. In this case, conclusions 14 and 15 are simply cut due to their uselessness.
Important! The only conclusion that needs to be left is the sixteenth. It is adjacent to the main wire. But at the same time it must be turned off.
On the rear wall of the power supply, install a potentiometer-regulator R10. It is also necessary to pass two cords: one for connecting the terminals, the other for the power supply. Additionally, you need to prepare a block of resistors. It will allow for adjustment.
To make the above-described unit, you will need two current-sense resistors. Your best bet is to use 5W8R2J. Power of 5 W is sufficient. The resistance of the unit will be equal to 0.1 ohm, and the total power is 10 watts.
For tuning, you need a trimmer resistor. It is attached to the same board. Part of the print track is removed first. This will eliminate the possibility of communication between the body and the main circuit, and also greatly enhance the safety of the car charger.
Before as solder pins 1, 14-16, they must first be tinned. Stranded thin wires are soldered. Full charge is determined by the open circuit voltage. Standard spacing is 13.8-14.2 V.
The full charge is set by a variable resistor. It is important that potentiometer R10 is in the middle position. To connect the output to the terminals, special clamps are installed at the ends. It is best to use the crocodile type.
The insulating tubes of the clamps must be made in different colors... Traditionally, red is a plus, blue is a minus. But you can choose any colors you like. It doesn't matter.
Important! Mixing up the wires will damage the device.
To save time and money when assembling a car charger, you can exclude a volt and ammeter from the design. The initial current can be set using potentiometer R10. The recommended value is 5.5 and 6.5 A.
Charger from adapter
The best option to create a car charger there will be a 12 volt adapter. But when choosing a voltage, you must first take into account the parameters of the battery.
The adapter wire must be cut at the end and exposed. About 5-7 centimeters for comfortable work will be sufficient. Wires with opposite charges must be laid at a distance of 40 centimeters from each other... A crocodile is put on at the end of each.
The clamps are connected to the battery in sequential order. Plus to plus, minus to minus. After that, all you need to do is turn on the adapter. This is one of the most simple schemes creating a charger for a car with your own hands.
Important! During the charging process, you need to ensure that the battery does not overheat. If this happens, the process must be interrupted immediately to avoid damage to the battery.
Everything ingenious is simple or a charger for a car from a light bulb and a diode
Everything you need to create this charger can be found at home. The main element of the design will be an ordinary light bulb. Moreover, its power should not be higher than 200 watts.
Important! How more power, the faster the battery will charge.
Some care must be taken when charging. Do not charge a small battery with a 200-watt bulb. Most likely this will lead to the fact that he just boils. There is simple formula calculation that will help you choose optimal power bulbs for your battery.
You will also need semiconductor diode that will conduct electricity in one direction only. It can be made from normal charging from the laptop. The final element of the design will be a wire with terminals and a plug.
It is very important to comply with safety rules when creating a car charger. First, always unplug the circuit before touching one of the components with your hand. Secondly, all contacts must be carefully isolated. There should be no exposed wires.
When assembling the circuit, all elements are connected in series: lamp, diode, battery. It is important to know the polarity of the diode in order to connect everything correctly. Use rubber gloves for added safety.
During circuit assembly Special attention pay attention to the diode. It usually has an arrow on it that looks at the plus. Since it only passes electricity in one direction, this is extremely important. A tester can be used to check the polarity of the terminals.
If everything is set up and connected correctly, the light will be on in half a channel. If there is no light, then you have done something wrong or the battery is completely discharged.
The charging process itself takes about 6-8 hours. After this time interval, the car charger must be disconnected from the mains in order to avoid overheating of the battery.
If you urgently need to recharge the battery, the process can be accelerated. The main thing is that the diode is powerful enough. You will also need a heater. All elements are connected in one chain. Efficiency similar method charging only 1%, but the speed is several times higher.
Outcomes
The simplest car charger can be assembled by hand in a few hours. Moreover, a set of necessary materials can be found in every home. More complex devices require more time to create, but they have increased reliability and good level security.
Now it makes no sense to assemble your own charger for car batteries: in stores huge selection ready-made devices, their prices are reasonable. However, let's not forget that it's nice to do something useful with your own hands, especially since a simple charger for a car battery can be easily assembled from improvised parts, and its price will be cheap.
The only thing worth warning about right away: circuits without precise adjustment of the current and voltage at the output, which do not have a cut-off current at the end of the charge, are suitable for charging only lead-acid batteries. For AGM and the use of similar chargers will damage the battery!
How to make the simplest transformer device
The circuit of this charger from a transformer is primitive, but functional and is assembled from available parts - the same way the factory chargers of the simplest type are designed.
At its core, it is a full-wave rectifier, hence the requirements for the transformer: since the output of such rectifiers has a voltage equal to rated voltage alternating current multiplied by the root of two, then at 10V on the transformer winding, we get 14.1V at the output of the charger. Any diode bridge is taken with a direct current of more than 5 amperes or assembled from four separate diodes, with the same current requirements, a measuring ammeter is also selected. The main thing is to place it on a radiator, which in the simplest case is an aluminum plate of at least 25 cm2 in area.
The primitiveness of such a device is not only a minus: due to the fact that it has neither regulation nor automatic shutdown, it can be used to "reanimate" sulfated batteries. But do not forget about the lack of protection against polarity reversal in this circuit.
The main problem is where to find a transformer of suitable power (at least 60 W) and with a given voltage. Can be used if a Soviet incandescent transformer comes along. However, its output windings have a voltage of 6.3V, so you have to connect two in series, rewinding one of them so that in total you get 10V at the output. An inexpensive transformer TP207-3 is suitable, in which the secondary windings are connected as follows:
At the same time, we unwind the winding between terminals 7-8.
Simple charger with electronic regulation
However, you can do without rewinding by supplementing the circuit with an electronic voltage stabilizer at the output. In addition, such a scheme will be more convenient in garage applications, since it will allow you to adjust the charge current when the supply voltage drops, it is also used for small car batteries, if necessary.
The role of the regulator here is played by the composite transistor KT837-KT814, variable resistor regulates the current at the output of the device. When assembling the charging, the 1N754A Zener diode can be replaced with the Soviet D814A.
Variable charger circuitry is simple to repeat and easy to surface mount without the need for etching printed circuit board... However, please note that field-effect transistors placed on a radiator, the heating of which will be noticeable. It is more convenient to use an old computer cooler by connecting its fan to the charger outputs. Resistor R1 must have a power of at least 5 W, it is easier to wind it from nichrome or fechral yourself or connect 10 one-watt resistors of 10 ohms in parallel. It is possible not to install it, but we must not forget that it protects the transistors in the event of a short circuit.
When choosing a transformer, be guided by the output voltage 12.6-16V, take either an incandescent transformer, connecting two windings in series, or select finished model with the correct voltage.
Video: The simplest battery charger
Alteration of the charger from the laptop
However, you can do without looking for a transformer if you have an unnecessary laptop charger at hand - with a simple alteration, we will get a compact and lightweight pulse unit power supply capable of charging car batteries. Since we need to get a voltage at the output of 14.1-14.3 V, no ready-made power supply will work, however, the conversion is simple.
Let's take a look at a section of a typical scheme, according to which devices of this kind are assembled:
In them, the maintenance of a stabilized voltage is carried out by a circuit from a TL431 microcircuit that controls an optocoupler (not shown in the diagram): as soon as the output voltage exceeds the value set by resistors R13 and R12, the microcircuit lights up the optocoupler LED, informs the PWM converter controller of a signal to reduce the duty cycle of the supplied to the impulse transformer. Hard? In fact, everything is easy to make with your own hands.
Opening the charger, we find not far from the TL431 output connector and two resistors connected to the Ref. It is more convenient to adjust the upper arm of the divider (in the diagram - resistor R13): by decreasing the resistance, we also reduce the voltage at the output of the charger, increasing it - we raise it. If we have a 12 V charger, we need a resistor with a high resistance, if a 19 V charger, then with a lower one.
Video: Charger for car batteries. Short circuit and reverse polarity protection. With your own hands
We solder the resistor and instead of it we install a trimmer, preset by the multimeter to the same resistance. Then, having connected the load (a light bulb from the headlight) to the output of the charger, we plug it into the network and smoothly rotate the trimmer slider, while simultaneously controlling the voltage. As soon as we get a voltage in the range of 14.1-14.3 V, disconnect the charger from the network, fix the trimming resistor engine with varnish (at least for nails) and assemble the case back. It will take no more time than you spent reading this article.
There are more complex circuits stabilization, and they can already be found in Chinese blocs... For example, here the TEA1761 microcircuit controls the optocoupler:
However, the principle of adjustment is the same: the resistance of the resistor soldered between the positive output of the power supply and the 6th leg of the microcircuit changes. In the above diagram, two paralleled resistors are used for this (thus, a resistance is obtained that comes out of the standard series). We also need to solder the trimmer instead of them and set the output to required voltage... Here's an example of one of these boards:
By dialing, you can understand that we are interested in a single resistor R32 (circled in red) on this board - we need to solder it.
On the Internet, there are often similar recommendations on how to make a homemade charger from computer unit nutrition. But keep in mind that they are all essentially reprints of old articles of the early 2000s, and similar recommendations for more or less modern blocks power supply are not applicable. It is no longer possible to simply raise the 12 V voltage to the required value in them, since other output voltages are also monitored, and they will inevitably "float away" with this setting, and the power supply protection will work. You can use laptop chargers that give out a single output voltage, they are much more convenient for rework.
