Every car owner should carry out diagnostics from time to time battery to save yourself from the problem of battery discharge. With a discharged battery, there is a possibility that starting car engine will be impossible, especially often such a problem arises in the cold season. What should be the voltage of the charged car battery and how to make a measurement with your own hands - we will tell you more about this below.
[Hide]
Normal battery voltage values
Battery charger
The most optimal indicator should be about 12.65 volts, it is allowed that the voltage is slightly less or less, by 0.5 V. If the charge value is less, this indicates insufficient charging of the device. For example, if the charge indicator is approximately 12.42 V, this indicates that the battery is approximately 80% charged. If the car battery voltage is 12.2 V, the charge level is 60%. In the event that this indicator is only 11.9 V, this indicates a critically low battery level, the use of such a battery may lead to the inability to start the motor.
Naturally, not so many car batteries can provide a voltage level of 12.65 V. As practice shows, on most devices the battery voltage value varies in the region of 12.2-12.4 V, which indicates a lack of charge. As for the maximum indicator, many manufacturers assure consumers that their batteries give out a charging voltage of 13-13.2 V. This is nothing more than a publicity stunt. It is of course possible to find batteries that provide around 13.2 volts, however this is rather an exception.
Do-it-yourself battery voltage measurement
If necessary, you can measure the voltage of a charged car battery at home. To diagnose this parameter, you need a multimeter or voltmeter.
The procedure for measuring and monitoring the charge of a partially or fully charged battery is as follows:
- First you need to remove the battery from seat car. Disconnect the terminals, if necessary, clean the device leads - if they are oxidized, the obtained values may be inaccurate. You should also clean the body of the device from dust and dirt. Dismantle the plate securing the battery, then remove it from its seat. Inspect the case carefully - there should be no cracks or other signs of damage on it, otherwise the inspection process will be impractical.
- Before starting the procedure, make sure that the level of the electrolyte solution in the jars is correct. To do this, unscrew each can and check the volume. If it can be seen that it is insufficient, that is, the liquid does not cover all the cans, distilled water should be added. Only then can you start measuring.
- First of all, the voltage level is measured without a load on the device, for this, connect the probes of a multimeter or voltmeter to the battery terminals, observing the polarity. That is, plus to plus, minus to minus. Switch on the tester and measure the value approximately 5 seconds after activation. As stated above, ideally the resulting reading should be approximately 12.6 volts. You can also test each individual jar - in this case, the tester should produce about 2.1 V.
- When the first stage of diagnostics is completed, you can proceed to the next one - now you should measure the same parameter, only under load. To implement this step, you will need to additionally enter a resistance, and its value must correspond to the battery capacity. The resistance should be approximately 0.01 ohm for batteries with a capacity of 100 Ah.
When resistance is set, the procedure is repeated in the same way. That is, the battery should be connected to the tester, and after 5 seconds the parameters are read. On average, under load, the voltage on the banks should be approximately 1.8 V, and the total charge level should be approximately 12.2-12.6 V (the author of the video on how to correctly measure the battery voltage - channel VAZ 2101-2107 REPAIR AND MAINTENANCE).
If during the diagnostics it turned out that the obtained values differ from the nominal ones, and the gap is large enough, then this indicates the need to solve the problem. If you continue to use vehicle with a partially discharged battery, this can lead to more serious problems later. If the values differ, you need to make sure that the tester used is completely functional, otherwise it may give incorrect results.
The test results do not correspond to the required ones - the actions of the car owner
So, if you are faced with a similar problem, then the most optimal way out of this situation would be to replenish the battery charge using charger... If you have the appropriate device, then you can do everything yourself at home.
There are several ways to recharge your device at home:
- Accelerated option. In most modern chargers that are sold in the car market today, this mode is called Boost. It should be noted that this method is more relevant if you urgently need to start the engine for a trip, and there is simply no time to recharge the device. The charging procedure makes it possible to replenish the battery capacity much faster as a result of using more high strength current.
Please note that this option cannot be used permanently, as this can lead to the destruction of the plates installed inside the structure, respectively, to a decrease in the service life of the device as a whole. The accelerated charging method can only be used in extreme, exceptional cases. - Another option is with constant voltage. This method of replenishing the capacity is based on maintaining a constant value of volts at the contacts. Most modern chargers use this option as automatic. Most experts recommend resorting to this method when the device's discharge level is not critical, that is, it corresponds to at least 12 volts.
It should be noted that this option is most often used among our compatriots. Its main advantage is that the car owner does not need to constantly monitor the process, in particular, when it comes to automatic chargers. Such devices allow you to automatically determine the state of charge of the device, and if the device replenishes its charge, the device itself will turn off the power. Also the advantage of this method is that it does not destroy the internal structure of the battery. - The next way is with direct current... As the name implies, this method is based on conducting and direct current through car battery... The charging procedure is carried out in several stages, at each of which there is a gradual decrease in the current. If you urgently need to start the engine and go somewhere, then this option will not work for you, since it is the longer of all the ones described above. Implementation this method more relevant if the battery is completely and deeply discharged - the direct current method will make it possible to more optimally replenish the battery's capacity without destroying its plates.
The only, but the most significant drawback is that the car owner will need to constantly monitor the implementation of this task, to measure the voltage. And when the procedure is completed, you will need to disconnect the battery from the power supply in time.
Many car owners are familiar with the situation when, even with a slight frost, the battery, which worked perfectly last winter, barely spins up the cooled engine. Often, problems with the battery begin to be felt already at 5–10 ° C below zero, so it is best to check the condition of the battery even before the onset of the first cold weather, because the battery is one of the important elements of a car's electrical equipment. Therefore, every car owner should definitely know how many volts the battery should show with a full charge.
Why does a car need a battery
The primary task of the battery is to start the motor, i.e. the rechargeable battery generates enough energy to start it. If necessary, the battery can play the role of an additional source of energy that helps the current generator to cope with the increased load that may arise in the electrical network in the case of simultaneous use of various electronic devices... If the generator is out of order, then thanks to the battery, the driver will be able to drive to the nearest station Maintenance... In some situations, the battery stabilizes the voltage in the vehicle's charging system.
Lifetime
It should be noted that often motorists judge the state of the battery by the number of years of its service, however, this is wrong. The lifespan is determined by the charge-discharge cycles of the battery and the conditions in which it was used. Each time a discharged battery is not charged for a long time, the number of cycles of its operation will decrease.
The deeper the depth of discharge and the longer the recharge time is not performed, the more cycles will be lost.
Only a charged battery can ensure the stable operation of the vehicle's electrical network. A battery with a maximum charge at a load of 3-5 A shows 12.6-12.9 V. This can be checked using a device that experts call a load plug. This device consists of a voltmeter to which two contacts, resistances and handles are attached.
The charge check is carried out as follows: in a car with the engine turned off, the headlights are lit, after which the voltage on the battery is measured. The measurement is best done after the vehicle has stood with the engine not turned on for 8 or more hours. You need to wait for the specified time so that everything chemical processes that occur in the battery while the vehicle is in motion have stopped.
If measurements are taken immediately after stopping the engine, then the load fork shows inaccurate data.
reference Information
- It is important to take into account that the measurement of the battery charge must be carried out in a warm room. This is explained by the fact that low temperature air reduces the battery charge.
- Directly charging the battery should be carried out in a well-ventilated place away from sources of fire. These precautions are mandatory because during the charging process, an explosive mixture is released into the atmosphere, the basis of which is oxygen and hydrogen.
- After charging, the battery case must be thoroughly cleaned of dirt particles and acid if it gets on its surface.
A battery that is serviced in a timely manner will last much longer. Periodic charging of the battery prevents premature loss of battery capacity.
The service life of the car battery is not calculated guaranteed by the manufacturer years, but the number of "discharge / charge" cycles. The more competently the operation and maintenance of the battery is organized, the less often you will have to buy a new one. The question of the voltage rating at the battery terminals worries many motorists.
What it should be in "static", everyone knows - about 12.6 V. This is the norm. And its value when the car engine is running? Will it change or not, and if so, in which direction? Here we will deal with this.
If there are no complaints about the battery, then checking the voltage at its terminals with the engine running allows you to diagnose the generator. That is, to determine how correctly the latter functions, and in general, whether it gives charge or not.
No specialist will give an unequivocal answer about the voltage level on the car battery. The main reason is that it is not known what operating mode of the engine is meant and the other consumers of electricity / energy are turned on (or not). These include (who forgot) - headlights, lights with turn signals, a stove and a number of others, depending on the car model. By the amount charging current(hence, the voltage on the battery) is partially influenced by the air temperature. Few people take this into account, but it is this factor that leads to some variation in the readings of the device.
Let's try to summarize all the data on the voltage values on the battery (in V):
A good battery () at the terminals should have at least 12.4. Voltage 12.5 - 13 is considered the norm. A lower value indicates a high degree of discharge. Another reason is a decrease in capacity due to the onset of sulfation of the plates, for example. And this is already a "bell" for the owner of the car. Moreover, at voltage = 12 and below, it is quite problematic to start a car, especially when cold weather sets in.
Engine running
The norm is a voltage of 13.5 - 14.
Exceeding the value (for example, up to 14.2) is a sign of a strong battery discharge (). In this case, the generator is forced to supply an increased current. This is the main reason. For cars equipped with various electronics, there is a second one. Cold room temperature sensors can correct the generator mode. The result is the same - overestimated voltage at the battery terminals.
What is it fraught with? If after 8 (± 2) minutes the voltage level returns to normal, then everything is in order. The car electronics worked. And if this does not happen, then the likely result is "boiling away" of the electrolyte and overcharging of the battery.
Low voltage on the battery with the engine running (less than 13) - evidence that the battery charge mode is not correct. What could be the reasons?
First, in the battery itself. Development of a resource, sulfation are the main problems that car owners most often face.
Secondly, either the generator is not working well, or there is a malfunction in the electric / circuit. For example, an increased leakage current with a decrease in the insulation resistance. As a rule, defects in the sheathing of wires, which lead to breakdown and short circuit.
Third, there is a problem with contacts. This should be checked immediately. Remove the terminals, inspect them and the battery terminals for oxidation. If necessary, clean and tighten the fasteners.
How to check the voltage on the battery - watch the video:
- It is impractical to use the capabilities of the on-board PC to measure the voltage on the battery. The result will differ from the true value due to the specifics of connecting the computer to the on-board network. Therefore, errors cannot be avoided. And the approximate data, given a certain range of parameters, will tell the owner of the car little.
- V normal work generator and good condition The battery can be verified as follows. Switch off all consumers and start the engine. The multimeter should show about 13.6 ± 1. Further, one by one, one of the electrical / network devices is turned on. For example, headlights, then low beam. Each of the electric devices "sets" the voltage by 0.2. But in total - not less than 12.8. Otherwise, the battery will run out rather quickly.
- Even if the battery meets all the requirements described, a comprehensive check should be carried out regularly. Good battery must "keep" the tension. If the car was not used, but, for example, after a few days the multimeter showed a value significantly lower than in the previous test, then the battery is already "at the limit". You need to be especially careful with her.
The author draws attention to the fact that all recommendations are rather approximate, generalized. But it is precisely such simple techniques that allow even inexperienced car owners to understand the state of the battery, whether the generator is working and how correctly the battery is being recharged. For a more detailed study of all component parts onboard power / network should be contacted by specialists.
A car battery consists of 6 cells connected in series. Each can has a full charge of 2.10-2.15V, so total stress summed up, is 12.6 - 12.8 V. What is the voltage of the battery after disconnecting the charger? When installing a battery in a car, the voltage after charging should be 12.4 V. This is normal. The battery of the car is starting, it is discharged during the period of starting the engine, in the process of movement it restores energy from the generator of the car. If the voltage in the battery drops to 12 V, the device requires charging from the mains. Big loss The charge in the banks is characterized as a deep discharge that destroys the battery.
The car, which is operated with the advantage of long mileage, has time to fully charge from the generator for the next start. But its charge will not be full. The state of charge of the battery can be determined by the voltage at the terminals. The smaller the value, the weaker the electrolyte concentration in the cans.
You can check the battery charge using a multimeter. The graduation should be set " alternating current»And measure the indicator at the terminals. The charge level can be determined by the density of the electrolyte.
The state of charge of a car battery is determined by the voltage as shown in the table.
To increase the capacity of the battery, you need to charge it with a special charger. This is a voltage converter, rectifier. Batteries are serviceable, maintenance-free, gel, AGM, lithium. Their charging voltage and current differ in voltage, time, cycle duration. There are universal chargers designed to switch modes for different models Battery, regulation of parameters.
Battery terminal voltage when charging
To charge the battery from the charger, select the constant current or voltage mode. Both are equally effective, but apply to different batteries. In the process of charging and operating the battery, it is necessary to measure the voltage at the terminals of the acid battery.
To charge a 12 V battery, you will need to set the constant voltage mode to 16-16.5 V. Using a current of 14.4 V, you can charge the battery 75-85%. At constant voltage the strength of the charging current is variable, it is limited only by the charger.
What charging voltage do I need to set? Proceeding from the achievement of a critical voltage, accompanied by "boiling" - the release of gas from the cans of a car battery. A battery is considered to be normally charged, with a voltage at the terminals from 12.6 to 14.5 V. on-board computer... Measurements with the engine running and with the battery disconnected are different.
The permissible charging voltage at the battery terminals when the engine is running varies 13.5 -14 V. The indicator shows the undercharge of the battery if the voltage is higher. It is necessary to repeat the measurement after 2 minutes, the battery may have been discharged at startup. If the charging voltage is low, the battery is losing its resource or problems come from car generator... You need to take measurements by turning off the on-board systems.
By measuring the charging voltage of the battery on an idle car, it is impossible to identify problems with the generator, however, the state of charge of the battery is well determined. A voltage of 12.5 - 14 V indicates no problems. If the indicator is low, you need to check:
- electrolyte state - the substance should be transparent, the level is normal;
- much depends on the battery charge level;
- determination of the possibility of recharging to the optimum voltage.
Testing will reveal problems with the battery, its performance.
Battery charging with constant resistance
Is it possible to charge a battery with a constant resistance? From the formula I = U * R, it is clear that if you set the resistance to a constant value, then the current or voltage will become variables. But inside the battery, resistance is a variable that affects the absorption of energy. The impedance is the sum of the polarization resistance, which changes and ohmic, which remains stable under the same conditions and for a particular battery.
The resistance is influenced by temperature, degree of discharge, electrolyte concentration, taken into account in the characteristics of the battery discharge curves. But if in the formula the resistance is a variable in time and in the state of the car battery, then current, voltage, or a combination of current and voltage can be constant during charging. To smooth out the magnitude of the charging current, a resistor is used - a ballast resistance.
What voltage to set when charging the battery
Voltage is a potential difference, and the current will flow in the direction where this value will be smaller. Therefore, the voltage of the charger is always selected to be higher than the charge level of the car battery. The greater the voltage difference, the faster and more fully the vehicle battery will gain capacity after charging.
During charging at constant voltage, the limit of the parameter set on the charger is lower than the characteristic at which gas evolution begins from the battery being serviced. What is the potential difference needed to charge a car battery? The maximum voltage used when charging the battery is 16, 5 V. What parameter should be, depends on the type of battery. The time and completeness of charging the battery depends on the voltage. The ratio of charging voltage, capacity recovery for a 12 V battery in 24 hours is as follows:
- The 14.4 V voltage can charge the battery up to 75-80%;
- Using a voltage of 15 V, the state of charge is 85 - 90%;
- With a voltage of 16 V, the battery is charged at 95 - 97%;
- With a maximum voltage of 16.3 -16.5 V, the batteries are fully charged.
When the battery voltage reaches 14.4 - 14.5, the charging end signal lights up on the charger.
It has been established that it is precisely this voltage of the car battery that does not generate gassing after and during charging. Therefore, in the real operation of cars, the generator through the voltage regulator limits the maximum voltage level to this value. In summer, this indicator is close to 100% capacity, in winter it corresponds to 13.9-14.3 V, with the motor running, which corresponds to 70-75% of the capacity.
Maximum battery charging voltage
We know, modern cars high class have on-board system operating at 16 V. What batteries are used in these batteries? In order to avoid gas evolution, the system must be closed.
This means that maintenance-free Ca / Ca batteries can withstand harsh environments. A special charging mode is used for them. The use of calcium instead of antimony allows the battery to be charged with increased voltage, while the electrolyte boils. Maintenance-free battery does not tolerate sudden voltage drops in on-board network... It is designed for cars with a good system electronic control voltage. Hybrid batteries made of low antimony and calcium plates are more tolerant to operating conditions.
Battery voltage at the end of charging
After the battery is fully charged, the charge will change slightly. Dissociation of the electrolyte occurs with filling of the pores of the current-carrying plates. The car battery installed in the engine compartment takes on the temperature the environment, and the capacity will change upward in heat or drops in sub-zero temperatures. Therefore, after charging, you can find out exactly what the voltage of the car battery is by installing it in place. Even while in the workshop, the voltage at the terminals changes. This is especially noticeable if the cycle has not been completely completed and the charging current has not dropped to 200 mA. In this case, a redistribution of the charge occurs, and additional feeding of the device with energy is possible.
But if, after charging the battery, the voltage drops on a running machine, this is a reason for revising the generator or replacing the battery.
Dependence of battery charging on voltage
Each type of battery is charged based on the characteristics of the type of construction used. Serviced, gel and lithium batteries have the lowest charging voltage. Reasons for boiling, destruction of the composition, fire hazard. If the serviced battery can be charged with the simplest charger, lithium and gel systems require compliance with a 2-stage combined mode of energy storage.
All systems are designed to prevent overcharging and are equipped with automatic shutdown power supply when the voltage is reached, which is required for the car battery. When charging, a gradual decrease in current strength occurs due to an increase in resistance, the voltage remains stable. After charging, the electrochemical reaction process continues, in the form of a slight self-discharge.
It is important that the charging voltage always exceeds the parameters required for operating the device. In order for the current to flow, a slope is needed, which is the voltage difference between the charger and the battery.
Video
We suggest looking at the advice of a specialist on how to properly charge and maintain a car battery, what voltage should be on the battery after charging.
Car owners will not hurt to find out what should be the voltage on the battery. Normal indicators allow us to talk about sufficient battery charging and its high operational capabilities. With reduced parameters of the power supply, problems may arise with and the functioning of auxiliary devices necessary for comfortable operation.
Basic measuring instruments
Before talking about what should be the voltage on the battery, you need to familiarize yourself with the basic devices designed to take readings. With their help, you can make the most accurate measurements in the normal state and under load.
- The multimeter is a universal device for working with various electrical circuits. Instruments can be analog or digital. However, as a rule, the latter are applied. The readings in this case are displayed on a special display of small dimensions.
- Load fork. In a simple version, it contains a voltmeter with the ability to measure resistance. The body is usually made of metal. It is located on a special handle. More complex devices may contain additional elements.
It is not recommended to use the load plug too often, as the condition of the battery may deteriorate from regular measurements. In the case of a multimeter, there are no restrictions.
Indicators in the normal state
First, you need to understand what should be the voltage on the car's battery without the load created by additional devices and the engine when starting. Ideally, the power supply should provide 12.6-12.8 volts. At lower rates, it is advisable not to operate the battery, since lead sulfate will form on the plates, which can lead to a decrease in capacity.
Indicators under load
It is also necessary to find out what should be the voltage on the battery when the engine is not running, but under load. In this case, the health of the power supply can be determined. Using load fork voltage in any case must be above 9 volts.
If the drawdown is too large, then first of all it is necessary to charge the battery and retest. The indicators will not increase when the battery life is exhausted.
Charge Chart
Immediately after measurements taken without load, the condition of the battery can be determined. Knowing what voltage the battery should give out when fully charged, it is quite easy to establish its capabilities in a specific situation. To do this, you can use the presented table.
Voltage in volts | Percentage charge level |
Measurements with the engine running
When the car engine is running, the indicators increase slightly. Typically, the battery voltage ranges from 13.5-14.0 volts. If the charge level is too low, the readings will increase as the generator will operate in boost mode.
Although it was given above what the battery voltage should be when the engine is running, it can be slightly higher for 10-15 minutes after starting. If during this time it does not recover, then there is a problem with the generator or electrical equipment.
After taking measurements, it may turn out that the voltage has not increased, but has dropped somewhat. In this case, the battery simply does not have time to charge normally. For verification, it is recommended to gradually start up electrical consumers, making measurements between switching on of devices. The indicators will decrease significantly (by 0.2-0.5 volts or more) if the generator is faulty.
Battery operating rules
Even if you clearly know what should be the voltage on the battery, with misuse it will not be possible to maintain it for a long time. Therefore, you should adhere to the special rules for operating the battery.
About recharging
The power source must be recharged at the right time, then the voltage will be optimal during operation. However, when holding such an event, certain requirements must be observed.
- Charging must be carried out at a positive air temperature.
- The filler plugs should be unscrewed and left directly in the holes before connecting to the mains.
- The device used must have a voltage of 16 volts.
- Do not tighten the plugs for 20 minutes after shutdown. Accumulated gases must completely leave the interior.
- The device is charged in a room with supply and exhaust ventilation.
As a conclusion
Information about what should be the voltage on the battery will help you easily identify problems with starting the engine and the functioning of various devices. If the indicators are normal, then the reasons should not be sought in the power supply system.
It is advisable to make measurements with the aforementioned devices. It is impossible to use the on-board PC for these purposes, since the error will be too high. This is primarily due to the peculiarities of connecting the device directly to the network.
The battery should be checked regularly. If the car has not been operated for several days, and the measuring device shows a significant decrease in voltage, then the power source has practically exhausted its resource.
