In modern practice, there are still cars that do not have an on-board computer or a display with a battery charge indicator. Driving without an indicator may result in the engine stopping completely and making it impossible to start it in the future.
The battery charge indicator performs two functions: it shows the charging current of the battery from the generator and informatively the amount of battery charge. There are several ways to fix this problem in a car. One of them is the simplest, to make a device with your own hands indicating battery charging.
Available sources contain many proposals for manufacturing a digital current circuit for such a device. It has a fairly simple appearance. To do this, you need skills in soldering radio components and the desire to assemble the device with your own hands. Select LED, Zener diode, breadboard and resistors. The diagram of the battery charge indicator is shown in the figure below.
Principle of operation
The LED indicator, thanks to the presence of three LED colors, can show different phases of charging current. Start of charging. Working middle. Process end warning. This circuit gives us the ability to control the entire operating cycle of the battery.
It’s not difficult to solder the parts yourself, but first check with a tester. If all the parts are in good order, you can make the assembly according to the diagram. The tester's nickname is LED output. We determine the low voltage output from six to eleven volts.
This is a red LED. From eleven to thirteen volts - yellow. More than thirteen - there will be a green LED. The circuit has a simple set of parts and works reliably.
Interesting! The battery supplies a certain voltage to the LED. It lights up. This is how we determine the beginning and end of battery charging.
If you don’t have any components, then you need to look at similar diagrams on the Internet and modify the device yourself. The circuit will also reliably show the battery current charge indication.
For a car, it is important that the circuit does not work all the time, but only when the driver is behind the wheel. It is recommended that after finishing the work with your own hands, you mount the resulting device under the steering wheel and connect it to the ignition switch. In this case, the indicator will only work when the car ignition is turned on.
We see that after finishing the work, you can create a battery charge indicator that is convenient and necessary for reliable operation of the car with your own hands. The cost of such a product will not be high.
Important! The reliability of the indicator and the convenience of its placement make it possible to effectively eliminate the imperfections of designers and car manufacturers.
On the one hand, any device, be it a vehicle or a simple kitchen utensil, seems perfect and refined from a technical point of view. Does not require the intervention of human thought and competent hands.
On the other hand, there will always be competent “Kulibins” for whom this device seems imperfect and requires improvement and technical refinement.
Progressive technical progress is built on this. A seemingly simple, but at the same time vitally important visual indication of the process of charging a car battery, not designed by designers, found its simple development by simple admirers of the world of science and technology.
Not all cars have an indicator that displays the battery charge level. The car owner must independently monitor this indicator, periodically checking it with a voltmeter, having previously disconnected the battery from the car's electrical network. However, a simple electronic device will allow you to get approximate indicators without leaving the salon.
Selection of circuit and components
Finished design
Structurally, a homemade battery charge monitoring indicator consists of an electronic unit, on the body of which there are three LEDs: red, blue and green. The choice of color may be different - it is important that when activating one of them, the information received is correctly interpreted.
Due to the small size of the device, you can use a regular breadboard. The optimal device circuit is pre-selected. You can find several models, but the most common and therefore workable version of the battery charge indicator is shown in the figure.
Diagram of the board and its components
Before installing components, it is necessary to arrange them on the printed circuit board according to the diagram. Only after this can you cut it to the desired size. It is important that the indicator has minimal dimensions. If you plan to install it in a housing, you should take into account its internal dimensions.
This circuit is designed to monitor the operation of a car battery with a network voltage from 6 to 14 V. For other values of this parameter, the characteristics of the components must be changed. Their list is shown in the table.
A battery charge indicator is a necessary thing in the household of any motorist. The relevance of such a device increases many times over when, for some reason, a car refuses to start on a cold winter morning. In this situation, it’s worth deciding whether to call a friend to come and help you start from your battery, or whether the battery has died for a long time, having discharged below a critical level.
Why monitor your battery's condition?
A car battery consists of six batteries connected in series with a supply voltage of 2.1 - 2.16V. Normally, the battery should produce 13 - 13.5V. Significant discharge of the battery should not be allowed, since this reduces the density and, accordingly, increases the freezing temperature of the electrolyte.
The higher the battery wear, the less time it holds a charge. In the warm season, this is not critical, but in winter, side lights forgotten while turned on can completely “kill” the battery by the time it is returned, turning the contents into a piece of ice.
In the table you can see the freezing temperature of the electrolyte, depending on the degree of charge of the unit.
| Dependence of the freezing temperature of the electrolyte on the state of charge of the battery | ||||
|---|---|---|---|---|
| Electrolyte density, mg/cm. cube | Voltage, V (no load) | Voltage, V (with load 100 A) | Battery charge level, % | Electrolyte freezing temperature, gr. Celsius |
| 1110 | 11,7 | 8,4 | 0,0 | -7 |
| 1130 | 11,8 | 8,7 | 10,0 | -9 |
| 1140 | 11,9 | 8,8 | 20,0 | -11 |
| 1150 | 11,9 | 9,0 | 25,0 | -13 |
| 1160 | 12,0 | 9,1 | 30,0 | -14 |
| 1180 | 12,1 | 9,5 | 45,0 | -18 |
| 1190 | 12,2 | 9,6 | 50,0 | -24 |
| 1210 | 12,3 | 9,9 | 60,0 | -32 |
| 1220 | 12,4 | 10,1 | 70,0 | -37 |
| 1230 | 12,4 | 10,2 | 75,0 | -42 |
| 1240 | 12,5 | 10,3 | 80,0 | -46 |
| 1270 | 12,7 | 10,8 | 100,0 | -60 |
A drop in charge level below 70% is considered critical. All automotive electrical appliances consume current, not voltage. Without load, even a severely discharged battery can show normal voltage. But at a low level, during engine startup, a strong voltage drop will be noted, which is an alarming signal.
It is possible to notice an approaching disaster in a timely manner only if an indicator is installed directly in the cabin. If, while the car is running, it constantly signals about discharge, it’s time to go to the service station.
What indicators exist
Many batteries, especially maintenance-free ones, have a built-in sensor (hygrometer), the operating principle of which is based on measuring the density of the electrolyte.
This sensor monitors the condition of the electrolyte and the relative value of its indicators. It is not very convenient to climb under the hood of a car several times to check the condition of the electrolyte in different operating modes.
Electronic devices are much more convenient for monitoring the condition of the battery.
Types of battery charge indicators
Automotive stores sell many of these devices, differing in design and functionality. Factory devices are conventionally divided into several types.
By connection method:
- to the cigarette lighter socket;
- to the on-board network.
By signal display method:
- analog;
- digital.
The principle of operation is the same, determining the battery charge level and displaying information in a visual form.
Schematic diagram of the indicator How to make a battery charge indicator using LEDs?
There are dozens of different control schemes, but they produce identical results. It is possible to assemble such a device yourself from scrap materials. The choice of circuit and components depends solely on your capabilities, imagination and the assortment of the nearest radio store.
Here is a diagram to understand how the LED battery charge indicator works. This portable model can be assembled “on your knee” in a few minutes.
D809– a 9V zener diode limits the voltage on the LEDs, and the differentiator itself is assembled on three resistors. This LED indicator is triggered by current in the circuit. At a voltage of 14V and above, the current is sufficient to light up all the LEDs; at a voltage of 12-13.5V they light up VD2 And VD3, below 12V - VD1.
A more advanced option with a minimum of parts can be assembled using a budget voltage indicator - chip AN6884 (KA2284).
Circuit of LED battery charge level indicator on voltage comparator
The circuit operates on the principle of a comparator. VD1– a 7.6V zener diode, it serves as a reference voltage source. R1– voltage divider. During the initial setup, it is set to such a position that all LEDs light up at a voltage of 14V. The voltage supplied to inputs 8 and 9 is compared through a comparator, and the result is decoded into 5 levels, lighting the corresponding LEDs.
Battery charging controller
To monitor the condition of the battery while the charger is operating, we make a battery charge controller. The device circuit and components used are as accessible as possible, while at the same time providing complete control over the battery recharging process.
The operating principle of the controller is as follows: as long as the voltage on the battery is below the charging voltage, the green LED lights up. As soon as the voltage is equal, the transistor opens, lighting up the red LED. Changing the resistor in front of the base of the transistor changes the voltage level required to turn on the transistor.
This is a universal monitoring circuit that can be used for both high-power car batteries and miniature lithium batteries.
The quality of battery charging determines how successfully the car will start. Not many drivers monitor the battery charge level. The article discusses such a useful device as a car battery charge indicator: how it works, how it works, instructions and a video on how to make it yourself.
[Hide]
Characteristics of the battery charge level indicator
On modern cars with an on-board computer, the driver has the opportunity to obtain information about the level. Older models are equipped with analog voltmeters, but they do not reflect the true picture of the battery's condition. Battery voltage indicator (VIN) is an option to have operational information about the battery voltage.
Purpose and device
The IN is assigned two functions - to show how the battery is charged from the generator, and to inform about the amount of charge of the car battery. The easiest way is to assemble such a device with your own hands. The circuit of the homemade device is simple. Having purchased the necessary parts, it is easy to assemble the indicator with your own hands. This way you can save money, since the cost of the device is low (the author of the video is AKA KASYAN).
Operating principle
The charge level indicator has three LED lights of different colors. Usually these are: red, green and blue. Each color has its own informative meaning. Red color means low charge, which is critical. Blue color corresponds to operating mode. Green color indicates the battery is fully charged.
Varieties
IN can be placed on batteries in the form of a hydrometer or in the form of separate devices with an information display. Built-in IDs are usually placed on. They are equipped with a float indicator (hydrometer). It has a simple design.
Factory identification numbers are available:
- DC-12 V. The device is a construction set. With its help, you can monitor the charge of the battery and the performance of the relay regulator.
- For those who have a car equipped with a second battery, a useful device will be a panel with an indicator from TMC. This is an aluminum panel with a voltmeter placed on it and a switch from one battery to another.
- ID Signature Gold Style and Faria Euro Black Style - determine the battery charge level. But their cost is too high, so there is little demand for them.
Guide to making a device at home
The simplest and cheapest option is a self-made IN. Its purpose is to control how the battery operates when the voltage in the on-board network is within the range of 6-14V.
To prevent the device from working constantly, it should be connected through the ignition switch. In this case it will work when the key is inserted.
The following parts will be needed for the diagram:
- printed circuit board;
- resistors: 2 with a resistance of 1 kOhm, 1 with a resistance of 2 kOhm and 3 with a resistance of 220 Ohm;
- transistors: VS547 - 1 and VS557 - 1;
- Zener diodes: one for 9.1 V, one for 10 V;
- LED bulbs (RGB): red, blue, green.
For LEDs, using a tester, you need to determine and check the pins so that they match the color. The device is assembled according to the diagram.
The components are tried on the board and cut to the appropriate sizes. It is advisable to arrange the components so that they take up less space.
It is better to solder LEDs to wires rather than to a board, so that the indicators can be more conveniently placed on the dashboard.
Based on the manufactured device, it is impossible to determine specific battery voltage values; you can only navigate within what limits it is located:
- red lights up if the voltage is from 6 to 11 V;
- blue corresponds to voltage from 11 to 13 V;
- green means fully charged, meaning the voltage is greater than 13V.
The battery voltage indicator can be installed anywhere in the cabin. It is most convenient to place it at the bottom of the steering column: the LEDs will be clearly visible and will not interfere with control. In addition, the device can be easily connected to the ignition switch. After installation, the driver will always be able to know how charged his car’s battery is and charge his battery if necessary.
- 20.09.2014
A trigger is a device with two stable equilibrium states, designed for recording and storing information. A flip-flop is capable of storing 1 bit of data. The trigger symbol looks like a rectangle with the letter T written inside it. Input signals are connected to the left of the rectangle. Designations of signal inputs are written in an additional field on the left side of the rectangle. ...
- 23.11.2017
Thermocouple (thermoelectric converter) is a device used in industry, scientific research, medicine, and in automation systems. Mainly used for temperature measurement. The operating principle is based on the Seebeck effect or, in other words, the thermoelectric effect. There is a contact potential difference between the connected conductors; if the joints of conductors connected in a ring are at the same temperature, the sum of such differences ...
- 17.01.2019
The TEA5767 IC manufactured by NXP is used to design low-voltage FM radio tuners. The TEA5767 has internal circuits for selecting intermediate frequency and demodulating the received signal, which allows you to make do with a minimum set of external components. Technical parameters of TEA5767: Supply voltage from 2.5 to 5 V Current consumption at Up = 5 V 12.8 mA Sensitivity 2 ...
- 20.09.2014
The brand of ferromagnetic material, type and type of magnetic circuit are selected depending on the purpose of the component, operating frequency, requirements for electromagnetic interference, and so on. In accordance with GOST 20249-80, the magnetic cores of transformers and chokes operating at a frequency of 50 Hz are made of electrical steel grades 1511, 1521, 3411, 3412 with a thickness of 0.2...0.5 mm. Application of magnetic cores from...
