Ferrari

Is it possible to charge a charged car battery? Do I need to charge a new car battery after purchase and in what cases? What to look for when buying a new battery

During engine operation, the rechargeable battery (), regardless of the type (maintained or maintenance-free battery), is recharged from the car generator. To control the battery charge, a device called a relay regulator is installed on the generator.

The very operation of a car in winter often involves short trips, turning on a large number of energy-intensive equipment (heated mirrors, windows, seats, etc.) The load on the battery increases significantly. At the same time, the battery simply does not have time to charge from the generator and compensate for the losses spent on launches. Taking into account the above, it is optimal to fully charge the battery with a charger to 100% at least once a year before the onset of cold weather.

Let us add that in case of problems with starting the engine due to engine malfunctions (problems with fuel equipment, etc.), the owner has to turn the starter much longer and more intensely. In such cases, you will need to charge the battery with an external charger much more often.

Charging the battery with a charger

To know how to charge a maintenance-free car battery with a charger, as well as charge a maintenance-free battery, you must follow certain rules. The charger (charger, external charger VZU, jump charger) is actually a capacitor charger.

A car battery is a source of constant current. When connecting the battery, it is imperative to observe the polarity. For this purpose, the connection locations for the positive and negative terminals are indicated by the positive and negative signs (“+” and “–”) on the battery. The terminals on the charger have similar markings, which allows you to correctly connect the battery to the charger. In other words, the “plus” of the battery is connected to the “+” terminal of the charger, the “minus” on the battery is connected to the “-” output of the charger.

Please note that accidentally reversing the polarity will cause the battery to discharge instead of charging. It is also necessary to take into account that a deep discharge (the battery is completely drained) can in some cases damage the battery, as a result of which it may not be possible to charge such a battery using a charger.

It is also necessary to take into account that before connecting to the charger, the battery must be removed from the car and thoroughly cleaned of possible contaminants. Acid stains can be easily removed with a damp cloth, which is moistened in a solution with soda. To prepare the solution, 15-20 grams of soda per 150-200 grams of water is enough. The presence of acid will be indicated by foaming of the specified solution when applied to the battery case.

As for serviceable batteries, the plugs on the “cans” for filling acid should be unscrewed. The fact is that during charging, gases are formed in the battery, which must be provided with a free exit. You should also check the electrolyte level. If the level drops below normal, distilled water is added.

What voltage to charge a car battery with?

Let's start with the fact that charging a battery involves supplying it with such a current that the battery does not have enough for a full charge. Based on this statement, you can answer the questions with what current to charge the car battery, as well as how long to charge the car battery with a charger.

If a battery with a capacity of 50 Amp-hours is 50% charged, then at the initial stage the charging current should be set to 25 A, after which this current should be dynamically reduced. By the time the battery is fully charged, the current supply should stop. This principle of operation underlies automatic chargers, with which a car battery is charged on average in 4-6 hours. The only disadvantage of such memory devices is their high cost.

It is also worth highlighting semi-automatic type chargers and solutions that require completely manual configuration. The latter are the most affordable and widely available on sale. Taking into account that the battery is usually 50% discharged, you can calculate how long to charge a maintenance-free car battery, and also understand how long it takes to charge a maintenance-free car battery.

The basis for calculating the battery charging time is the battery capacity. Knowing this parameter, the charging time is calculated quite simply. If the battery has a capacity of 50 Ah, then to fully charge it is necessary to apply a current of no more than 30 Ah to such a battery. The charger is set to 3A, which will require ten hours to fully charge the battery with the charger.

To be 100% sure that the battery is fully charged, after 10 hours you can set the charger current to 0.5 A, and then continue charging the battery for another 5-10 hours. This charging method does not pose a danger to car batteries, which have a large capacity. The downside is the need to charge the battery for about a day.

To save time and quickly charge the battery, you can set the charger to 8 A, and then charge it for about 3 hours. After this period, the charging current is reduced to 6 A and the battery is charged with this current for another 1 hour. As a result, it will take 4 hours to charge. Note that this charging mode is not optimal, since it is advisable to charge the battery with a small current of up to 3 A.

Charging with a high current can lead to overcharging and excessive heating of the battery, resulting in a significantly reduced battery life. We also note that the use of battery charging methods, which are aimed at minimizing the negative process of plate sulfation, in practice does not have noticeable positive results.

Proper operation of the battery depending on its type (maintained and unmaintained), avoidance of deep discharge and timely charging using a charger allow the acid battery to operate properly for 3-7 years.

How to assess the condition and charge of a car battery

Proper charging and a number of conditions that must be observed during operation of a car battery can ensure normal engine starting even in extremely low temperatures. The main indicator of the condition of the battery is the degree of its charge. Next we will answer how to find out if the car battery is charged.

Let's start with the fact that some battery models have a special color indicator on the battery itself, which indicates whether the battery is charged or discharged. It is worth noting that this indicator is a very approximate indicator, by which only the need for recharging can be determined with a certain degree of probability. In other words, the charge indicator may indicate that the battery is charged, but the starting current at low temperatures is not enough.

Another way to determine the battery charge level is to measure the voltage at the battery terminals. This method also allows a very rough assessment of the state and degree of charge. To measure, the battery will need to be removed from the car or disconnected from the charger, after which you need to wait an additional 7 hours. The outside air temperature is not of fundamental importance.

12.8 V - 100% charge;
12.6 V-75% charge;
12.2 V-50% charge;
12.0 V-25% charge;
A voltage drop of less than 11.8 V indicates a complete discharge of the battery.

You can also check the battery charge level without waiting. To do this, the voltage at the battery terminals must be measured by the load using so-called load forks. This method is more accurate and reliable. The specified plug is a voltmeter; a resistance is connected parallel to the voltmeter terminals. The resistance value is 0.018-0.020 Ohm for a battery with a capacity of 40-60 Ampere-hours.

The plug must be connected to the corresponding outputs on the battery, after which after 6-8 seconds. record the readings displayed by the voltmeter. Next, you can estimate the degree of charge of the battery by voltage using a load plug:

10.5 V - 100% charge;
9.9 V - 75% charge;
9.3 V - 50% charge;
8.7 V - 25% charge;
An indicator of less than 8.18 V means the battery is completely discharged;

You can also take measurements in the absence of a load plug without removing the battery from the car. The battery must be connected to the vehicle's on-board network. Then you will need to put a load on the battery by turning on the headlights and high beam headlights (for cars with standard halogen lamps). The headlight bulbs have a power of 50 W, the load is about 10 A. The voltage of a normally charged battery in this case should be about 11.2 V.

The next way to check the battery charge is to measure the voltage at the battery terminals at the moment when the internal combustion engine is started. These measurements can be considered reliable only if the starter is working normally.

At the time of start-up, the voltage reading should not be below 9.5 V. A voltage drop below this mark means that the battery is heavily discharged. In this case, it needs to be charged using a charger. This test method also allows you to identify starter problems. A known good and 100% charged battery is installed on the car, after which a measurement is made. If the voltage at the battery terminals at the time of starting drops below 9.5 V, then problems with the starter are obvious.

Finally, we add that measurements using different methods involve recording fluctuations in fractions of a volt. For this reason, increased demands are placed on the voltmeter. The accuracy of the device is extremely important, since the slightest error of even one or two percent will lead to an error in measuring the state of charge of the battery by 10 -20%. For measurements, it is recommended to use instruments with minimal error.

How to charge a completely dead car battery

A common cause of deep battery discharge is simple inattention. Often it is enough to leave the car with the lights or headlights, interior lighting or radio on for 6-12 hours, after which the battery is completely discharged. For this reason, many car owners are interested in the question of whether it is possible to restore a completely discharged battery.

As you know, completely discharging a battery greatly affects the battery life, especially when it comes to a maintenance-free battery. Manufacturers of car batteries indicate that even one full discharge is enough to cause the battery to fail. In practice, relatively new batteries can be restored at least 1 or 2 times after they are completely discharged without significant loss of performance properties.

First, you need to determine how much the battery is discharged using one of the above methods. You can also immediately charge the battery. Next, the completely discharged battery must be charged in the mode recommended by the battery manufacturer. The standard is to supply a charge current value at 0.1 of the total battery capacity.

A fully charged battery is charged with this current for at least 14-16 hours. For example, consider charging a battery with a capacity of 60 Amp-hours. In this case, the charge current should be on average from 3 A (slower) to 6 A (faster). A completely discharged car battery should be properly charged with the smallest current, and for as long as possible (about a day).

When the voltage at the battery terminals does not increase any more for 60 minutes. (assuming the same charging current is supplied), then the battery is fully charged. Maintenance-free batteries, when fully charged, assume a voltage value of 16.2±0.1 V. It should be borne in mind that this voltage value is standard, but it also depends on the battery capacity, charging current, electrolyte density in the battery, etc. Any voltmeter is suitable for measurement, regardless of the instrument’s error, since it is necessary to measure a constant, not an exact voltage.

How to charge a car battery if there is no charger

The easiest way to charge the battery is to start the car using the “lighting” method from another car, after which you need to drive the car for about 20-30 minutes. For charging efficiency from the generator, either dynamic driving in high gears or driving in low gears is assumed.

The main condition is to maintain crankshaft speed at around 2900-3200 rpm. At the specified speed, the generator will provide the necessary current, which will allow you to recharge the battery. Note that this method is only suitable if the battery is partially, not deeply, discharged. Also, after the trip you will still need to fully charge the battery.

Quite often, car enthusiasts are interested in what else can be used to charge a car battery, besides a charger. Most often, chargers that charge mobile phones, tablets, laptops and other gadgets are supposed to be used as a replacement. Let us immediately note that these solutions do not allow you to charge a car battery without a series of manipulations.

The fact is that the main condition for supplying current from the charger to the battery is that there must be a voltage at the output of the charger that will be greater than the voltage at the battery outputs. In other words, if the battery output voltage is 12 V, the charger output voltage should be 14 V. As for various devices, their battery voltage often does not exceed 7.0 V. Now imagine that you have a gadget charger at hand that has the required voltage of 12 Q. The problem will still be present since the resistance of the car battery is measured in whole Ohms.

It turns out that connecting charging from a mobile device to the battery outputs will actually constitute a short circuit of the terminals of the charging power supply. The protection will be triggered in the unit, as a result of which such a charger will not supply current to the battery. In the absence of protection, there is a high probability of failure of the power supply from a significant load.

It is worth adding that the car battery should also not be charged from various power supplies that have a suitable output voltage, but they are structurally unable to adjust the amount of current supplied. Only a special charger for a car battery is a device that has at its output the required voltage and current to charge the battery. In parallel with this, it is possible to control a constant current value.

Homemade charger for a car battery

Now let's move from theory to practice. Let's start with the fact that you can make a battery charger from a power supply from a third-party device with your own hands.

Please note that these actions pose a certain danger and are performed entirely at your own peril and risk. The administration of the resource does not bear any responsibility, the information is presented for informational purposes only!

There are several ways to make a charger. Let's take a quick look at the most common ones:

Making a charger from a source that has a voltage of about 13-14 V at its output, and is also capable of providing a current of more than 1 Ampere. A laptop power supply is suitable for this task.
Charging from a regular household electrical outlet of 220 Volts. To do this, you will need a semiconductor diode and an incandescent lamp, which are connected in series in a circuit.

It should be borne in mind that the use of such solutions means charging the battery using a current source. As a result, constant monitoring of the time and moment of the end of the battery charge is required. This control is carried out using regular voltage measurements at the battery terminals or counting the time for which the battery is charged.

Remember, overcharging the battery leads to an increase in the temperature inside the battery and the active release of hydrogen and oxygen. Boiling of the electrolyte in the battery “banks” causes the formation of an explosive mixture. If an electrical spark or other ignition source occurs, the battery may explode. Such an explosion can cause fires, burns and injuries!

Now let’s focus on the most common method of making a charger for a car battery yourself. We are talking about charging a laptop from the power supply. To complete the task, certain knowledge, skills and experience in the field of assembling simple electrical circuits are required. Otherwise, the best solution would be to contact a specialist, purchase a ready-made charger, or replace the battery with a new one.

The manufacturing scheme of the charger itself is quite simple. A ballast lamp is connected to the power supply, and the outputs of the homemade charger are connected to the battery outputs. A lamp with a small rating will be required as a “ballast”.

If you try to connect the power supply to the battery without using a ballast light bulb in the electrical circuit, then you can quickly damage both the power supply itself and the battery.

You should select the right lamp step by step, starting with the minimum ratings. To begin with, you can connect a low-power turn signal lamp, then a more powerful turn signal lamp, etc. Each lamp should be tested separately by connecting it in a circuit. If the light is on, then you can proceed to connecting an analogue with more power. This method will help not damage the power supply. Finally, let’s add that the battery charge from such a homemade device will be indicated by the burning of the ballast lamp. In other words, if the battery is charging, then the lamp will light, even if very dimly.

The new battery must be fully charged and operational, that is, it requires immediate installation on the car to begin further use. Before purchasing, it is necessary to check the battery according to a number of parameters:

hull integrity;
voltage measurement at the outputs;
checking electrolyte density;
date of manufacture of the battery;

At the initial stage, it is necessary to remove the protective film and inspect the case for cracks, drips and other defects. If the slightest deviation from the norm is detected, it is recommended to replace the battery.

Then the voltage is measured at the terminals of the new battery. You can measure voltage with a voltmeter, but the accuracy of the device does not matter. The voltage should not be below 12 Volts. A voltage reading of 10.8 Volts indicates that the battery is completely discharged. This indicator is unacceptable for a new battery.

The density of the electrolyte is measured using a special fork. Also, the density parameter indirectly indicates the battery charge level. The final stage of testing is determining the release date of the battery. Batteries that were produced 6 months ago. You should not purchase back or more from the day of the planned purchase. The fact is that a ready-to-use battery has a tendency to self-discharge. For this reason, for long-term storage the battery must be prepared in advance, but in this case the battery can no longer be considered a new finished product.

It turns out that the answer to the question of whether a new car battery needs to be charged will be negative. There is no need to charge a new battery. If the battery you plan to purchase is discharged, then it may simply be old, used, or have a manufacturing defect.

What is the problem?

Or why charge the battery without removing it from the car? Monitoring forums, autoblogs, stories from friends and acquaintances and, perhaps, even personal experience, allows us to identify the following pattern: when the battery is disconnected, all settings and settings of the on-board computer, multimedia system and other devices connected to the network are lost. Of course, you want to avoid lengthy reconfigurations of all electronics, which are abundant in a modern car.

In the opposite situation, there is a risk of equipment failure. On the one hand, the loss does not seem critical if we are talking about a radio or a clock; on the other hand, new cars can be equipped with rather expensive electronic devices, the performance of which, in addition, can be fundamental for the normal functioning of all car systems.

Consequences of battery disconnection

There is no strictly defined range of consequences of disconnecting the battery when it is necessary to charge it. Actually, even in car models that are very similar in functionality, when removing the terminals, you can find completely different results. The most common occurrences are:

resetting the on-board climate control settings in the cabin;
blocking the standard radio.

Of course, such problems do not pose great threats. To unlock the media, you just need to enter the code, and the electrical adaptation settings themselves will be restored after a couple of tens of kilometers. However, less common, but no less unpleasant consequences of briefly disconnecting the battery from the car circuit also occur:

climate system settings failure;
deleting RAM memory;
failures in the system of modern speaker systems, which may lead to the need to reinstall the software.

Obviously, after a car owner encounters at least one of the described (or undescribed) problems, he has a desire to eliminate them in the future. Therefore, the question of whether a battery connected in a circuit can be charged becomes relevant and quite logical.

So, is it possible to charge without removing the terminals?

The simplest and shortest answer to this question may be “you can”! However, due to the complexity of the system, of course, there are many “BUTs”!

Having delved into the literature and notes of car enthusiasts, you can easily find both supporters and opponents of this approach. The pros and cons are distributed in the same way as the answers to the question whether it is possible to remove the battery terminals while the car engine is running. An analysis of forums and reviews from car enthusiasts on the topic can be briefly described as follows: against isolated evidence of unpleasant consequences, dozens of reviews that everything went well. So, there are few victims, however, their presence indicates a risk.

Charging the battery, which is carried out without removing the terminals, is fraught with high voltage entering the vehicle network. In principle, devices should normally tolerate surges up to 15.7 V. However, as practice shows, anything can happen. Therefore, to minimize the likelihood of electronics failure, it is recommended to use a charger that has safe current output parameters. Thus, if you are planning to charge a dead battery without disconnecting it from the network, you should carefully familiarize yourself with its characteristics. As a rule, in the documentation supplied with the car battery charger, the manufacturer notes whether it is safe (especially when used in automatic mode) for the car's electronics.

It is much less likely that problems will arise if a factory device is used. An attempt to charge a connected battery with a homemade device can lead to the described undesirable consequences with a much higher probability.

While charging is in progress, it is better to constantly monitor the operation of the charger. In addition, experts recommend adhering to certain rules when recharging:

The terminals should be connected in this order: first “plus”, then “minus”. You need to turn off the device in the reverse order.
Avoid contact between the charger wires and the surface of the battery, tubes and metal parts of the car.
The charger should be connected to the 220 V electrical network after the battery is connected, and disconnected after disconnecting the terminals.
Do not turn on any devices in the car during charging.
Do not leave the charging device unattended.
Ensure good ventilation of the room in which charging is carried out.

However, the procedure for recharging a car battery that has not been removed from the car does not differ from the standard one.

Summary

Thus, the answer to the question whether it is possible to charge the battery without removing it from the car is “you can”. But in some cases, if there are fluctuations in the car’s network caused by unstable operation of the charger, you can lose expensive devices connected to the car’s electrical circuit.

Many car enthusiasts, when buying a new battery, ask themselves: do they need to charge it?

If it is 95-100% charged, then there is no need for this, but do not rush to put a new battery on the car - it needs to be checked and, in some cases, properly charged. Before describing these cases, let's look at some practical tips for choosing a new battery.

We assume that you have chosen the battery size, capacity, polarity, manufacturer, and now the seller has placed the desired purchase in front of you. Where do we start? From inspection, of course.

Inspect and test the battery before purchasing

First you need to carefully examine it externally. It should not have any deep scratches, cracks, dents, etc. Check for electrolyte leakage. Sometimes during transportation the corners of the case are damaged and cracks form.

Check for protective caps or covers on the battery conductors. If they are not there, check their presence on similar batteries. The absence of caps and covers may indicate that the battery is stale or has already been in use (used as a replacement battery or involved in starting the car).

You need to carefully inspect the current terminals. They must be positioned strictly vertically in relation to the top cover. Sometimes sellers rent out batteries and, as a result of unqualified connection of the terminals or inept handling of keys, the down conductors are bent. Subsequently, problems may arise with the connection of current-carrying wires or with the integrity of the battery case in the area of the current terminals.

On a new battery, the current leads must have a smooth surface; no chips or scratches are allowed. If stripes are felt, then the current conductor has been crimped with a terminal and, accordingly, the battery is used and has already been used.

At all levels, until the battery reaches the buyer, checks are made with a load fork and a multimeter, and the presence of small indented points on the upper edges of the down conductors is allowed.

It is necessary to carefully inspect the filler plugs (if any). They should not show any obvious signs of opening.

The journey from the manufacturer to the store sometimes takes up to six months. Therefore, you should try to choose a battery with a shelf life of no more than six months. It is not recommended to buy older ones. The date of manufacture is engraved on the battery case.

Batteries from foreign manufacturers have their own markings, so don’t be lazy before going to the store, find on the Internet and print out the markings of specific models.

If you are offered to buy a battery that has had six months or more since its release, then it is better to refuse such a purchase. Save your nerves and money.

There are also such situations - you chose a new battery and went to remove your old one from the car. At this time, the seller checks the battery you have chosen, and it is discharged - 12.2 V. If the seller is unscrupulous, then he can quickly put it on charge for a couple of minutes, the voltage will rise, but the state of charge will not increase. The battery will be discharged, but the voltage will show close to normal - 12.7 V. After a short charge, it is simply in the “vigorous” mode.

Also, please note that in hypermarkets such as Auchan, batteries remain sealed without periodic recharging for more than five months. Naturally, without operation and periodic recharging, they lose capacity due to self-discharge. Accordingly, the more time has passed since the battery was released, the more discharged it is.

Battery testing

When purchasing, you should also ask the seller to test the battery using a load fork. We wrote about load forks

Additionally, to assess the condition of the battery, you can use a special tester, for example, OptiMate Test TS120N, from TecMate, retail price is approximately 3,300 rubles.

To test the battery, you need to connect a tester to it according to the wire markings: red to the “+” terminal of the battery, black to the “-” terminal of the battery.

If the red LED is on, the battery is low, the voltage is below 12.5 V.

The green LED is lit - a charged lead-acid battery with a voltage of 12.5-13.1 V.

If the green LED is blinking, there is a charged Lithium/LiFePO 4 battery with a voltage of 13.2-13.5V.

or BatteryBug BB-SBM12, its cost is approximately 1,700 rubles.

This tester only works when the battery is connected to the car, so it cannot be used in a store. This is of course a minus, but it will definitely come in handy on the farm.

For those who are interested in this tester -.

Honest sellers in specialized stores periodically subject the batteries they sell to preventative recharging, so fully charged batteries go on sale, so there is no need to charge them.

But you need to carry out preventative recharging in any case; this does not pose any harm to the battery.

It is better to charge new batteries with a simple automatic device at a constant voltage of no higher than 14.8 V, without any fanaticism, for example, with devices such as Kedr, Katun, Polyus A, Orion, Vympel.

There is no need to use any homemade, manual, Soviet antediluvian devices.

Do I need to charge a new battery?

Many car enthusiasts, when purchasing a new battery, ask themselves the question: do they need to charge the newly purchased battery?

Answer: if the battery is 95-100% charged, then there is no need for this, but if it is discharged, be sure to charge it.

How to understand that the battery is discharged?

The main indicator of charge when purchasing a new battery is its open circuit voltage, where 12.7 V equals 100% charge, and every -0.1 V equals a loss of 10% of the total charge.

For example, a voltage of 12.3 V indicates that the battery is 40% discharged, respectively, the charge is 60%.

If the voltage on the new battery is less than 12.5 V, it is recommended to charge it.

The charge can also be determined by the density of the electrolyte (if the cans can be reached). A density of 1.27 g/cm3 is equal to 100% charge, and a drop of 0.01 is equal to approximately 6% of the total discharge.

In general, according to unspoken rules, stores are recommended to sell only charged batteries with a voltage above 12.5 V.

Many people think it's a light bulb. In fact, this is a simple device consisting of a glass tube and several colored balls. Depending on the level and density of the electrolyte, one or another ball floats up and a different color is visible through the peephole.

You shouldn’t really trust such a system, because the battery consists of six cells, and the indicator is installed only in one, the middle one. And if in any of the other cans the level or density of the electrolyte for any reason does not correspond to the norm, the indicator will not show this.

What is a dry-charged battery and does it need to be charged after purchase?

So-called dry-charged batteries installed on cars, motorcycles, mopeds, scooters, etc. are widely used today.

In dry-charged batteries, the plates are molded and charged during manufacture, but no electrolyte was poured into them when sent to retail chains. After assembly, sealed plugs are inserted into the battery to prevent moisture and air from entering.

What is the advantage of dry-charged batteries? In this condition, the shelf life increases to 5 years.

However, if you buy a dry-charged battery, do not expect that it is ready for use.

What do you need to have to commission a battery and how to do it?

If the purchased battery comes with instructions, you must read it carefully and follow the recommendations!!!

Some types of imported batteries come with a special container with ready-made electrolyte.

If you purchased a battery without a supply of electrolyte, then you need to buy ready-made electrolyte in the required volume.

It is sold in various packaging with a density of 1.27-1.28 g/cm3. The volume of electrolyte should be greater than the volume of the battery. If the battery instructions do not indicate the volume of electrolyte, then it can be approximately calculated based on the geometric dimensions of the case. You may also need distilled water.

You will also need a hydrometer and a charger. You can read how to choose a charger in.

Before starting the process of putting a dry-charged battery into operation, it needs to be prepared: remove the sealing sticker, remove the plugs from the filler necks.

The process of filling electrolyte and subsequent charging can be viewed here

If you ask a similar question to anyone who has at least some idea about the car and the battery, you can get the most detailed advice. For some reason, many people think that this issue is so trivial that it’s even a shame not to know it. However, statistics show that more than half of the batteries do not withstand the service life declared by the Manufacturer and have to be replaced prematurely with new ones.

And the main reason is improper charging during the operational period. Let's figure out how to charge the battery, and do it CORRECTLY.

Let's make one point clear right away. It is believed that if the car's generator works without failures, and the car is used regularly, then this is quite enough to maintain the proper level of battery charge. This opinion is fundamentally wrong, and here's why. According to its technical characteristics, the generator is not able to provide 100% charging, that is, the battery will always be partially charged, which significantly reduces its service life.

Remove the battery from the car

Often, car enthusiasts neglect this and charge the battery without removing it from the car. But in vain, and here's why.

Firstly, the battery needs to be systematically inspected, from all sides, and not just from above. It is possible that the electrolyte will splash (corrosion of the “mounting” socket frame will appear), or a crack in the housing (the result of constant vibration and unreliable fixation at the location).

Secondly, the product must be cleaned of dirt and dust. The fact is that the “patina” formed on the case, between the terminals, is conductive, which means that the degree of self-discharge of the battery increases, which negatively affects its service life.

Therefore, before charging the battery, it should be serviced. It is good to collect accumulated dirt, which contains acid, with a swab dipped in a weak soda solution. If foaming occurs, this indicates that not all the acid has been removed from the surface of the housing.

By the way, the terminals also require periodic maintenance, since lead oxidizes, and, therefore, more current is required when starting the engine, which leads to increased battery discharge.

If, after all, the battery is charged at the installation site, then the suitable (mains) wires from its terminals must be removed.

Unscrew the caps on the cans

You should also not forget about the need for their maintenance. In the center of each there is a small through hole through which the products of gas formation that occur during operation are removed. If it is clogged with dirt, then the accumulated gas can simply rupture the housing.

In addition, you need to make sure that the electrolyte level is normal. If necessary, add water (distilled).

Connect the charger terminals

Here you need to pay attention to the polarity. The “positive” is connected to the “+” of the battery, the “negative” - to the “-”.

Charging process

This largely depends on the type of device. However, many car enthusiasts prefer to do it manually. The current is set to the maximum (depending on the nominal capacity of the battery), and as the voltage decreases it is added.

It should be noted right away that a lot depends on how the battery is used, to what extent it is discharged, and how often the owner charges it from an external device. The “quality” of the car’s generator also has an impact.

The charging mode with low currents is considered the most optimal. More on this below. It remains to add that it is necessary to systematically monitor this process. Sometimes a car enthusiast simply puts the battery on charge and leaves for a few hours. This risks the fact that the battery may charge earlier (and the recharging process will begin) or even “reset” the current to a minimum. Then you will have to increase it and wait until it is fully charged.

With what we now know, we can answer some common questions that new car enthusiasts have.

How do you know that the battery is fully charged?

The voltage at its terminals can be different (from 14.5 to 16.1 V). This depends on many components (electrolyte density, capacity and a number of others). The main criterion is the constancy of the output voltage at its terminals while the charging process continues for 1 hour. It is measured by any type of voltmeter, regardless of its accuracy class.

Is it possible to do exercises at negative air temperatures?

Yes, since an electrolyte with the proper density never freezes. Example - the car is used not only in summer, but also in winter, and, nevertheless, recharging from the generator is not interrupted.

When charging from an external source, do I need to disconnect the battery from the on-board network?

Necessarily. Quite often, the battery is charged without removing it from its installation location. But here you need to take into account that some electronic device can be connected to the network, even with the ignition and ground turned off. In modern car models there are so many different features of engineering solutions that it is impossible to foresee everything, especially since not all Manufacturers describe such nuances in detail in the documentation for the “car”. Therefore, it is better not to take risks and play it safe, otherwise the higher-than-expected “voltage” of the charger may damage something.

How often should the battery be recharged if it is removed from the car?

Many motorists do not operate their “iron horses” in winter. During this time, a prudent owner removes the battery and stores it separately, in a warm room. But any device characterized by such a parameter as electrical capacitance gradually self-discharges.

Naturally, the electrolyte begins to react to low temperatures, and in a discharged state, in a cold room, the jars can simply freeze. Such a battery can no longer be restored. By the way, this is why it is necessary to remove it for the winter and put it in a “warm” place. Recommendations for recharging frequency vary. To avoid mistakes, it should be done approximately once every 3 months (provided that the battery is stored at above-zero temperatures).

If the battery is not removed from the car and it is not used, then it needs to be charged more often - once every 1.5 - 2 months. This is explained by the fact that it is possible to increase the self-discharge current through the on-board network. And if the wires are removed from the terminals, but it’s cold in the garage, then at least once every 2 weeks. It's more reliable.

What current should I set and how long should I charge?

There is a criterion that applies to all types of batteries - the charging current is 10% of the nominal capacity of the product. The most common batteries are 45 A/h (for passenger cars). Therefore, the optimal charge current is 4.5 A. If the discharge is complete, then at least 12 - 15 hours. In other cases - until fully charged. How to determine is indicated above.

Since the degree of rarefaction cannot be determined “by eye”, if the battery is not completely discharged, experts recommend using the “gentle” mode, that is, setting the current to 2 times less than the calculated one (for example, instead of 4.5 A, set it to 2.5). Naturally, it will take more time to charge, but the service life of the product will also increase.

Sometimes, to reduce charging time, car enthusiasts specifically provide increased current. Yes, this way the battery will charge faster. But this does not take into account the fact that the chemical processes occurring in this case begin to occur more intensely, and this entails an increase in the temperature of the electrolyte. Overheating the battery significantly reduces its shelf life.

Experienced car enthusiasts prefer this “technology” - the current is about half an ampere, and let it “stand.” Although it takes longer, it is quite safe for the battery. In this case, charging is achieved at 100 percent.

It remains to add that if you do not allow the battery to systematically discharge to a critical minimum (10.5 V), then the product will reliably serve not only 5 guaranteed years, but also more. Normal electrolyte density within the normal range is 1.25 - 1.27; voltage at the terminals - depending on the type of battery.