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Why the battery discharges quickly, how to find and eliminate the cause. Why does the car battery drain quickly? Why does the car battery not work?

The battery is a source of energy to power electrical equipment and start the car engine. A working battery retains its charge for 2-3 months.

However, there are times when the battery discharges much faster. This usually happens while the car is parked.

Why does my car battery drain?

It is difficult to determine the causes of battery discharge without special instruments. The culprit for voltage loss can be either the power supply equipment or the battery itself. The normal performance of the battery is influenced by several factors:

• battery wear;
• generator failure;
• climatic conditions;
• short circuit in the electrical equipment circuit.

The operating conditions of the vehicle also matter. When starting the engine, the starter consumes a lot of energy. It takes some time to restore the charge. With frequent trips over short distances, the generator may simply not have enough time to charge the battery.

Battery wear and problems

Checking the battery condition must be done with the engine off and no load (with the terminals disconnected). The density of the electrolyte is determined with a hydrometer; normal values ​​are considered to be 1.26 – 1.28 g/cc. Smaller numbers indicate an incomplete charge. When checking with a hydrometer, you should pay attention to the electrolyte level in each jar. Containers should be refilled with distilled water, observing safety precautions.

To check the battery with a tester, the device switch is set to the 20 V constant voltage control mode. The multimeter probes are connected to the positive and negative terminals of the battery. The charge level of the power supply is shown in the table:

Voltage, V

Tester readings of 11.8 V and below indicate that the battery is completely discharged. Its voltage is not enough to start the engine.

Regardless of the numbers on the display, the battery must be left at rest, and after some time the measurement must be taken again. If the next time the readings are significantly lower than the previous ones, the problem is in the battery. The power supply will require servicing or replacement. If the multimeter readings do not change within a few days, then the discharge is occurring for another reason.

Generator failure

The interaction of acid and alkali at low temperatures slows down, and in the cold the battery runs out much faster. In cold regions, it is recommended to increase the battery density to 1.28 - 1.30 g/cc. by adding electrolyte. True, such actions significantly reduce the service life.

"Shorty" in the electrical circuit

This problem is the most difficult to detect and fix. “Shorties” arise and appear periodically. This makes it difficult to detect and repair the breakdown. If the car is used frequently, the battery does not have time to discharge completely, and the owner of the vehicle is unaware of the presence of malfunctions for a long period.

Electrical equipment of vehicles consists of a single-wire positive circuit. The body, engine and all metal parts are a minus. When the positive and negative charge conductors come into contact, a short circuit occurs, causing the battery to die. Shorts can occur both in the wiring and in electrical appliances of the car.

The malfunction can be detected as follows. After turning off the ignition, remove the positive terminal and touch it to the positive terminal of the battery. If sparking occurs between the elements, it means there is a short circuit in the circuit. The next step is to look for current leakage.

How to determine the circuit in which a short circuit occurs

Any car has a current leak (alarm system, memory of the injection system controller, radio, clock, etc.). The acceptable value at which the battery will not discharge is 0.02 - 0.06 A. Before measuring current leakage, you must turn off all electrical appliances. It is important to remember to slam all doors and lock the limit switches under the hood. Leakage measurements are performed with the ignition off in the following order:

1. The tester switch is set to 10 Ampere measurement mode.
2. The negative wire is removed from the battery.
3. One probe of the device is connected to the removed wire.
4. The other probe of the tester is connected to the negative of the battery.

The polarity on the digital multimeter display does not matter.

Video - how to measure battery current leakage:

If the leakage current exceeds the permissible limit, you should look for the circuit in which the discharge occurs. To do this, all fuses are removed one by one and the device indicators are checked. If, after removing the next fuse, the numbers drop significantly, the problem must be looked for in that circuit.

Having figured out which devices a certain conductor protects, you need to disconnect them from consumption one by one. The fuse must be reinstalled. A decrease in the current leakage indicator on the display will indicate the problematic element.

Advice! To ensure a guaranteed result, it is advisable to check all fuses, since faults can be present in several circuits at the same time.

In order to permanently get rid of current leaks during parking, you need to install a ground switch in the negative wire circuit from the battery terminal to the body.

What to do if the battery is dead

If the power supply charge is not enough to start the engine, and the trip cannot be postponed, you can try to start the car in other ways.

The “lighting up” method (using the charge of a nearby vehicle) will allow you to start the engine from the starter. In order to “light” a neighbor you will need special wires.

If they are absent, you can borrow someone else’s battery for 5-10 minutes, and after starting the engine, return yours to its place. The described method will allow you to simultaneously check the functionality of the generator. The downside is that not everyone will want to remove the battery from their car.

Important! When removing/installing the battery with the engine running, it is important to prevent the positive terminal from coming into contact with metal elements of the car. Otherwise a short circuit will occur.

A vehicle with a low battery charge can be used. Towing will require another vehicle and a cable, or the physical assistance of several people. The engine is started in second/third gear when accelerating the car at 10-20 km/h. Old Soviet cars included a special crank handle (the so-called “crooked starter”), with which you can start the car without outside help.

When starting the engine unconventionally, it is necessary to temporarily refrain from using powerful electrical appliances (stoves, lights, etc.). A working generator will restore normal charge in 15 - 20 minutes of engine operation at medium speed.

The described methods of starting the engine are a necessary measure. Starting the engine from a pushrod can damage the vehicle. Therefore, at the first signs of battery discharge, you should immediately carry out a set of measures to inspect the power supply circuit and troubleshoot problems.

What it shows and what information the driver receives.

Read about choosing a battery for a car.

We suggest you remember the signals of the traffic controller so that there is no doubt about the correctness of your actions.

Video - checking current leaks in a car:

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Comments on the article:

Semyon

It is better to launch “from a pusher” in top gear. The starting speed is quite enough, and the risk of breaking the belts becomes less.

Anya

I have been driving for 5 years, and my driving experience is the same. My car is small, an old used Matiz. And during this time, my battery was discharged several times precisely from standing for a long time, and in the cold season. A couple of times they actually “lit it up” - a neighbor in the parking lot helped, he also had special wires, 2 times they pulled me on the cable from 2nd gear. Well, in winter, my husband had to remove the battery at night so that he wouldn’t have to charge it. True, it’s not inconvenient to carry it back and forth, but the battery is heavy, at least for me. And I haven’t learned how to install and remove the battery myself.

Sergey Mikhailovich

When I drove a classic, I often encountered the problem of the battery discharging or, so to speak, freezing in the cold season. I solved the problem by purchasing an additional external battery (the same as for phones, only 40,000A) with the ability to connect crocodiles. Very comfortably. And if you need to light someone up, no problem either.

Pavel Andreevich

We spent the night in the car on the way to Belarus, the ignition key was not taken out and it turned out that the lights had not turned off. In the morning we couldn’t start, the guy helped us and gave us a light. Since then I bought wires for lighting and take them with me.

Dmitriy

If you have to leave the battery in the car outside in winter, then in the morning it needs to be “excited”. I turn on the high beams for a few seconds.

Ivan Shevelev

When I bring it home when it’s cold, I use the same simple trick as turning on the headlights for a few minutes.

gena 56

Battery drain is very common. It happens especially quickly in winter. This is primarily due to the fact that the battery is running out of service life. This can also happen due to not turning off the lighting devices during long-term parking. The most common way to fix this problem is to recharge using another car, since now almost everyone has wires for lighting.

Fedor

Disconnecting the battery while the engine is running on modern cars is a very dangerous task. A power surge occurs, and only God knows that the fuse and brains will burn out at this moment.

Yuri

When lighting a cigarette, it is advisable to wait a little after connecting the terminals so that the discharged battery is recharged. It will be easier to start, otherwise a lot will be lost in the wires. And so the original battery will provide more current - losses will decrease.

Vasya

In order to “light” the battery, you can also use a power bank. Now there are plenty of them. They won’t help someone who has been killed “to zero”, but they can heal someone who is hooked.

Elena

It's good for you men to reason. Someone removed the battery in the cold and took it home. What should we do as women? Should I cover it with a fur coat?

Alexander

If the battery in a modern car is dead, it is not advisable to disconnect it. I solved this problem by purchasing a portable compact starting battery with a charger function for a car with a gasoline or diesel engine. In winter, it helps to start the engine without putting a load on the battery. This means the battery will last longer. I drove on the original battery for 6 years.

Anton

I solved the problem simply. I bought an inexpensive second battery and take it with me. If necessary, I swap them and recharge the discharged one. It may be an expensive pleasure, but it is independent, the engine starts in any situation.

Artem

In winter, I solved a possible problem with starting the engine in the morning using a carrying lamp. With my night shift job, I had this opportunity. With the lamp turned on, I placed it on the engine close to the battery and closed the hood. In the morning, like in the summer - half a turn.

Boris

I only encountered a discharged battery in the winter. In such cases, my algorithm is as simple as five kopecks, and as reliable as an AK-47: turn on the high beam headlights for 5-6 seconds; if it doesn’t help, then we get a Chinese igniter at a cost of 2 thousand, but unfortunately in frosts of -20 it doesn’t always cope, therefore the only remaining option is to look for an already “warmed-up” neighbor in the parking lot with the goal of either “lighting” or “dragging.” Have a nice trip!

Oleg

I'll tell you about my experience with a dead battery. At the end of last year I went abroad to visit my daughter for 4 months. First, I removed the battery from the car, fully charged it with a charger (automatic) and left it in the garage. Imagine my surprise when I arrived and put it on the car - it was completely discharged, the electrolyte was frozen! The battery is only 2 years old, manufacturer Tyumen. How could a fully charged battery discharge to the point of freezing? All the neighbors in the garage said unequivocally - throw it away and buy a new one. But I decided to experiment. First I warmed it up, then charged it for 2 days with a weak current - about 0.5 A. Then I carefully drained all the electrolyte (the density did not rise above 1.2). I filled it with a new one and again 0.5 A for 24 hours. Now I drive and start it without problems in 20-degree frost.

Nikolay

Let me disagree with the author of the article on some points. He writes that you can check the charging without a tester. “After starting the engine, you need to disconnect one of the terminals from the battery. If the car doesn’t stall, then the generator is working.” This is bad advice, in a modern car such actions can lead to the output of the ignition module or ignition coil, and the diode bridge of the generator will also not be sweet. There can be a leak without any “shorts”, simply either the cable has become frayed and comes into contact with the ground, or moisture has entered. My leak was caused by the memory of the Pioneer radio. With the engine turned off, with the doors closed (this is mandatory), I plugged an ammeter into the negative bus gap and saw a consumption of 85 mA, which is already enough. And after the hassle with the fuses, I decided to remove the removable panel of the radio and the current immediately dropped to 9 mA.

Egor

Boris, -20 is not such a cold as to require tricks with an igniter and similar tricks. Any serviceable car at this temperature starts without any problems. There are “southern” foreign cars, and their controller allows starting up to -25.
So, if you have problems starting at -20, you’ll have a straight shot at a car service center. This is a manifestation of some kind of car malfunction.

Farut

The battery holds up well almost all year round, but as soon as frost sets in (-20-35) and it doesn’t last through the night, I’ve already done everything, nothing helps. Can anyone tell me what to do?

Egor

But my alarm constantly goes off. I've been driving my car for 15 years, during which time I've probably changed 4-5 batteries. While the battery is fresh, or relatively new, the effect is not so noticeable, even after 2 months. But after 2-3 years of operation it easily breaks down in two weeks. Somehow, out of interest, I bought a cheap tester and measured what amperage the alarm takes in security mode - it turned out to be about 150 milliamps, with more than half consumed by the engine shutdown relay. Slightly modernized the work scheme and voila! 25-40 milliamps in security mode! Now even batteries can last a year longer. 🙂

Ermakov Sasha

The first thing you need to do is find out the reason why the battery died. Perhaps this is not a disconnected consumer, but perhaps a short circuit in the plates of the battery itself. In the first case, we “light up” or drag it home to charge, and in the second we go to get a new battery. By the way, there is a third option - the generator (relay-regulator) does not work, in this case we also drag it to charge, but we are already looking for the generator.

Sergey

The most important thing is to timely measure the density in order to know in advance about the approximate time of battery failure. Nowadays there is not even a need to take measurements with a hydrometer; there are testers for determining density, without entering the inside of the case. Just fully charge the battery and take measurements with the result within 15-20 seconds, it all depends on the brand of the device.

Bogdan

When the car was parked under the house, problems with the battery were frequent, although I always took good care of the technical condition of the car. In the last two years I started putting it in the garage, and the battery no longer reminds me of itself.

Maria

Lighting a cigarette is of course an option, but you can light a cigarette so poorly that you end up going to a car service center

Dmitriy

I’m reading the article and all the comments and I never tire of being surprised - we discuss and look for reasons: someone’s wiring is shorted, someone’s relay-regulator, someone’s even a generator, they forgot to take out the key, turn off the sidelights, or the signaling ate everything up. I just want to ask, have you washed the battery? After all, you wash your car when it’s dirty.
The main and first reason for battery self-discharge is dirt on its surface. Don’t be lazy, take a voltmeter and connect its probe to any terminal of the battery, and move the second probe along the surface of the battery. And what would you see? Say nothing, the second probe is not connected anywhere, i.e. the voltmeter will show 0 V. That's right, this is how it should be when the battery is clean, only in life you will see something different, up to 11 V!!! Your dirty battery loses about 2 Ah per day due to leakage current alone. And you say the alarm went to 0.
The reason for this dirt is the vapors coming out of the battery cells; this dirt on the surface perfectly conducts current, draining your battery.
Therefore, when you wash your car, do not be lazy to wash the battery case with a solution of ordinary baking soda, and then remove the white soda stains from the battery case with ordinary water.

Lyokha

There are no problems starting the car when the battery is dead; it starts easily either “with a pusher” or by “lighting up”. The problem will be to determine the reason why your account is discharged. And this reason must be eliminated as quickly as possible.

Oleg

Yes, there are no problems starting a car with a dead battery, either with a pusher or lighting a cigarette. The problem is different. So they gave you a light and you calmed down and drove off. And in a few days everything will happen again. After you have had to light a cigarette, remove the battery at night and put it on charge, the whole point is that it cannot be fully charged by your generator, any electrician will tell you this. The charge can only be 85%. Therefore, do not calm down, but make it a rule - if the battery is dead, then be sure to charge it from the charger. Well, of course, first find the reason for its discharge.

Denis

Probably everyone has had problems with a dead battery, sometimes there is no time to look for the reasons, sometimes someone helped light a cigarette and they forgot. I'm not an exception. But there are situations when you feel everything - enough is enough. So I decided to stop begging for a light and bought myself a Startmonkey 200 booster. Yes, it’s a little expensive, but it’s worth the money. Now there are no problems, I don’t even think about whether the battery is dead or not, neither in winter nor in summer. neither hunting nor fishing. It triggers not only me but also my friends. And when the car spends the night in the garage, I put both the booster and the original battery on charge.

Ivanovich

To prevent the battery from discharging when parked for a long time in the garage, if the battery and electrical equipment are in full working order, it is necessary to periodically start the engine to recharge the battery from its own generator. And then you will avoid an unexpected surprise.

Sergey

High humidity actually affects the independent discharge of the battery. Poor sealing of the hood can be a minor, but probable cause - you need to check the seals occasionally. Humidity accumulates on the surface of the battery and closes the circuit, so (if this is present) before parking you need to wipe it dry and remove one or both terminals.

Anton

If the battery is discharged for a reason unknown to you, you should try to charge it. To do this, remove it, connect it to the charger and start charging. If the battery does not take a charge, the matter is rubbish, only in exceptional cases can it be repaired, but nowadays it is better to buy a new one, there are always batteries on sale. This is my advice.

Nikita

The battery is discharged in the morning, the reason is the driver. Either they forgot to turn something off, or the surface of the battery was dirty, which led to a current leak, or they did not monitor the density of the electrolyte. In all cases, in the morning we look for someone to light a cigarette, for which I always carry a cigarette lighter drive with me. True, for the last couple of years I’ve mostly been lighting others with them. I bought myself a booster. And now there are no problems. Yes, it’s a little expensive, but in the morning you don’t have to worry about what’s wrong with the battery or who you need to light it from.

Alexander

One option is to remove the battery and warm it up, even without recharging. A “cold” battery does not hold high currents well. Of course, it’s even better to charge the battery when warming up.

Vladimir

There are different cases, you can just leave the light bulb on and by the morning all the charge will be drained. The simplest thing is if you are not in a hurry and have a charger at home, remove it and charge it, and if you need to go somewhere, you can light a cigarette and by the way, it will be sufficiently charged while you are driving, and if it is not a severe winter, it will start and continue normally, but it is better, of course, to recharge Fine.

Many motorists are faced with the problem of rapid battery discharge. What to do if the battery constantly runs out, why does this happen and is it worth buying a new battery? We will try to answer these and other questions in detail in this article.

1 The main reasons for the rapid discharge of the battery in a car

No matter how high-quality and expensive your car’s battery is, in some cases it can quickly discharge and not fully perform its main functions. There may be several reasons for this:

• Spent resource. If the battery has been in service for more than 3 years;
• Problems with the generator. There is no necessary power for the battery;
• Current leakage in the vehicle's on-board network.
• Low temperatures. In winter, the battery discharges much faster.

You should know that the average service life of a high-quality and reliable battery is 3-5 years, depending on the operating conditions of the vehicle. With prolonged or frequent use, the battery capacity drops noticeably and this manifests itself in the rapid discharge of the batteries; most often the battery discharges when parked, it usually runs out in a few hours, and if the wear is high enough, it runs out “to zero”, then is completely loses its functionality.

The main reason why a car battery sometimes drains quickly is chemical sulfation. Over time, a certain amount of lead sulfate accumulates on the oppositely polarized battery plates. This reduces the area of ​​interaction between the active electrodes and the electrolyte, which leads to rapid discharge. If the battery in your car has been in use for 3-5 years, and discharge occurs periodically, it means that the battery must be replaced, and no manipulations with it will help. If the battery was working properly, and one day it was discharged, and the battery was purchased recently, then the reason can be corrected, but you should look for it elsewhere.

2 Lack of power from the generator - how to determine and what to do?

Even if the car has a new battery, if there are problems with the power supply system while driving, that is, the generator, it will constantly discharge. To determine whether the generator is the cause of the constant discharge of the battery, you need to check the system with a special multimeter. To do this, start the engine and let it idle for a few minutes. Next, activate the maximum amount of electrical equipment in the car, that is, the radio, headlights, heated mirror glass, interior heating, etc.

After this, connect a multimeter to the battery terminals and measure the network voltage. The standard indicator for a normally operating generator is 13-14.4 Volts. If the reading on the voltmeter is less than indicated, it means that the battery is not receiving the required charge from the power supply system, and the reasons should be looked for in the generator. In this case, the following options are possible:

• the generator belt tension has weakened or it has broken;
• contacts and wiring are damaged;
• failure of the voltage regulator or diode bridge of the generator.

It is quite difficult to independently determine which of the reasons led to the breakdown, so it is better to entrust this to specialists. Of course, you can drive with a problematic generator, but this significantly affects the service life of the battery, and you cannot do without constant additional recharging.

3 Current leakage in the on-board network is a common cause of battery discharge

Another common reason why the battery is constantly discharged is a temporary or permanent current leak when the on-board network is broken. Current leakage can occur in several cases:

• contacts have oxidized or the insulation of internal wiring has been damaged;
• some electrical devices are not connected correctly;
• headlights, side lights, interior or trunk lighting, etc. were left on overnight.

If you are convinced that you did not leave any devices or lights on overnight, and the battery was discharged in the morning, but the generator is working, then the problem is definitely a current leak in the internal network.

Turn on the ignition and turn off all current consumers in the car. Take a multimeter and disconnect the negative terminal from the battery. Now connect the leads from the multimeter to the gap between the negative terminal of the battery and the terminal, this will allow you to measure the current leakage. The leakage rate in this case is considered to be from 15 to 35 Amps. If the indicators are within these limits, then the leakage is considered normal; if they are higher, you should contact an electrician at a car service center who will find the cause of the constant current leakage in the network.

4 Maintaining battery performance at low temperatures

If all electrical elements, including the battery itself, are fully operational, the density is good, and the temperature outside constantly drops below 5-7 degrees, then the battery may discharge due to loss of density. It is known that for one degree of frost, 1 ampere-hour of battery charge is lost, that is, if the capacity of your battery is 70 Am/h, then when the car is parked for several days in the cold, the capacity may completely drop, and in severe frosts the electrolyte may also freeze .

Therefore, for normal and uninterrupted operation of the battery in winter, experts recommend constantly maintaining a certain, preferably maximum, charge level. Also in winter you can slightly increase the density of the electrolyte. In severe frosts, special battery cases for the car also help, preventing rapid loss of battery capacity overnight while the car is parked, but if the temperature constantly drops below 10 degrees, it is better to take the battery home at night, this way you will definitely prevent its complete or partial discharge.

To extend the battery life in any weather, we also recommend purchasing a portable charger that can charge the battery from a regular household network. In addition, if possible, constantly check the electrolyte level on the jars and add distilled water if necessary. It is also advisable to prevent the battery from being completely discharged; if one day the starter starts to turn more difficult, this is the first sign of a decrease in battery charge. In this case, it is better to remove and additionally charge the battery, otherwise the next day it may completely run out.

Why does my car battery drain overnight?

The battery is a very important component of the machine. When the engine is turned off, it supplies current consumers in the on-board network and supplies current to the starter when the engine starts. When the engine is running, the battery helps the generator provide power to the car's network if it fails. Therefore, a car cannot do without a battery. When the battery is discharged, the car turns into a pile of metal. Moreover, the car’s battery can be discharged overnight, and the car owner was completely unprepared for this. Sometimes owners cannot even just get inside the car due to a dead battery. And the day before there was nothing to predict such a situation. After this, they wonder why the car battery is draining. In this material we will try to analyze the reasons for the rapid discharge of a car battery.

No matter how good and high-quality the battery you choose, in some situations it can still fail. Therefore, you shouldn’t be surprised that your car’s battery dies overnight, even if it’s new. There are reasons for this situation. The main reasons are presented below:

• The battery has exhausted its service life;
• the battery is not charged from the generator during the trip;
• current leakage in the on-board network;
• left the devices in the car on (headlights, heating, radio);
• temperature conditions (severe frost).

Now, let's look at these reasons in more detail.

Why does my car battery drain quickly?

This is probably the most common reason for a car battery to drain quickly. This problem is typical for batteries that have been used for 4-5 years. In addition to the fact that such a battery discharges quickly, it also significantly loses capacity by this time.

It is no secret that the main “scourge” of acid batteries is sulfation. This phenomenon is the accumulation of lead sulfate on plates of different polarities. As a result, the area of ​​the active mass on the electrodes, which interacts with the electrolyte, decreases.

Thus, the battery gradually loses its capacity, which by the end of its service life drops to 30% of its nominal value. What can you do to reduce sulfation and prevent your battery from draining quickly? Below are some recommendations:

• Avoid frequent engine starts and short runs. The battery consumes a large amount of energy when starting the engine. If you then drive the car a short distance, the battery will not have time to replenish the loss of charge from the generator. It's not surprising if it then runs out of charge overnight;
• Charge the battery periodically using an AC charger. It is harmful for the battery to be in a discharged state. This aggravates and accelerates the sulfation process;
• Do not allow the battery to be deeply discharged. This significantly reduces its service life. This is especially harmful for calcium. As a result, the battery loses a lot of capacity and can easily be completely discharged overnight;
• Regularly check the electrolyte level in battery banks and do not allow operation with exposed plates;
• Carry out preventative maintenance periodically.

If after using it for more than 3-4 years, then the battery has served its purpose. Only buying a new battery will help here. By the way, now stores often offer to purchase a new battery in exchange for an old one. So, do not rush to throw away your used battery.

No or insufficient battery charge

This reason is less common than the previous one, but still. Your battery may be fully charged and in good working order. But if the battery does not receive the necessary charge from the generator during a trip, it will not last long. After such a trip, you turn off the engine, leave the car, and the battery will drain overnight.

First, let's understand what normal battery charging from a generator means. To check the operation of the alternator on your car, you will need a multimeter. You need to start the engine, turn on the headlights, heated windows, and radio. After this, use a multimeter to measure the voltage at the battery terminals. It should be in the range of 13-14.4 volts. If it is less, the battery will not receive enough charge. If the value is higher, this will lead to intense hydrolysis and loss of water from the electrolyte.

The following are the main reasons why the battery may not charge from the generator:

• The generator belt has broken;
• The generator belt tension has weakened;
• Damage to contacts and wiring in the network;
• The generator voltage regulator has failed;
• The diode bridge of the generator burned out.

If you find a problem with charging the battery from the generator, contact a car service to determine the exact cause. You cannot drive with such a malfunction, since the battery will be discharged every night. You can read more at the given link.

A leak in the on-board network can be another reason for the battery to discharge overnight. If you have a leak that is larger than normal, then in the morning you may come to your car with a completely discharged battery.

The reasons for increased current leakage may be:

• oxidized contacts;
• worn wiring, damaged insulation;
• incorrect connection of electrical devices.

The procedure for measuring current leakage on a machine:

• you need to turn off the ignition, remove the key and provide access to the interior (open the windows) in case the doors are blocked by the central locking;
• turn off all current consumers;
• open the hood and remove the negative terminal from the battery;
• a multimeter in current measurement mode is connected to the gap between the negative terminal of the battery and the disconnected terminal;
• measure the leakage current.

The normal leakage current value is 15─70 mA. This is normal and there is no need to worry about such a leak. If the value is higher, you should contact an auto electrician. and its measurement are described in the article at the link.

Driver forgetfulness

It's simple. You forgot to turn off the headlights or heated windows, and your battery was discharged overnight.

It’s difficult to recommend anything here, other than remembering to turn off the car’s electrical appliances when parked. Manufacturers of many foreign cars, and even modern domestic cars, already turn off headlights, heating and other consumers automatically after a certain time after stopping the engine. This allows you to avoid deep discharge of the battery.

Temperature conditions

The battery may well be discharged overnight if there is severe frost outside. Winter, in general, is a difficult and problematic period for a car battery. At this time, problems with starting the engine are often observed. It is worth noting that below a temperature of 15 C, with a decrease of 1 degree, the battery capacity drops by 1 mAh. If the battery is discharged, the electrolyte may simply freeze in severe frost.

To prevent this from happening, you need to control the degree of charge of the battery based on the density of its electrolyte. Below you can see a table with the freezing temperature of the electrolyte depending on its density.

			Battery charge level, %
Electrolyte density, g/cm. cube (+15 degrees Celsius)	Voltage, V (no load)	Voltage, V (with load 100 A)	Battery charge level, %	Electrolyte freezing temperature, gr. Celsius
1,11	11,7	8,4	0	-7
1,12	11,76	8,54	6	-8
1,13	11,82	8,68	12,56	-9
1,14	11,88	8,84	19	-11
1,15	11,94	9	25	-13
1,16	12	9,14	31	-14
1,17	12,06	9,3	37,5	-16
1,18	12,12	9,46	44	-18
1,19	12,18	9,6	50	-24
1,2	12,24	9,74	56	-27
1,21	12,3	9,9	62,5	-32
1,22	12,36	10,06	69	-37
1,23	12,42	10,2	75	-42
1,24	12,48	10,34	81	-46
1,25	12,54	10,5	87,5	-50
1,26	12,6	10,66	94	-55
1,27	12,66	10,8	100	-60

People often ask me: Sergey, please tell me about the deep discharge of the car battery? There are so many legends and fables surrounding this topic. Why is it so dangerous, what are the reasons for its occurrence, and of course the consequences. After all, for some reason, it is acid batteries that are afraid of these discharges. But let’s say they are not so critical of it, they can be discharged many times! Why is that? There are several main reasons for this, but let's look at it step by step...

Discharging a battery is a normal process of its operation - first it accumulates energy, then releases it. The beauty of the battery is that it is multi-chargeable, that is, it’s not like the battery is used up and thrown away, but you can constantly charge a large number of cycles. However, the structure of the battery itself is far from ideal; if you like, this is a very capricious device:

• It cannot be recharged, otherwise the lead plates may fall off
• It cannot be “deeply” discharged, as they say to zero (more on this below)
• It is necessary to monitor the density of the electrolyte
• Maintain electrolyte levels
• Keep an eye on the banks, otherwise they may close

There are a lot of jokes, of course, now there are so-called maintenance-free batteries, they are less problematic and will protect you from problems with the electrolyte. BUT such issues as overcharging and deep discharge remain. Therefore, you need to operate your battery.

A little about discharge - charge

These processes are characterized by battery voltage. Many people have probably heard that the voltage on a car battery is 12V, but this is not entirely correct. . It's kind of 100% charged.

A strong discharge is approximately 10.5 - 11.0V, with such parameters you will no longer start your car. This is a kind of minimum threshold. Of course, you can discharge it to zero, that is, 0 Volts, this will be a deep parameter.

Briefly about the structure

The battery (as we have said more than once) consists of packages of lead plates (these are negative) and packages of lead dioxide (these are positive), a special dielectric is laid between them, which prevents the plates from bridging. Such “sets” are immersed in an acidic electrolyte (35% sulfuric acid + 65%), after which they are ready to accumulate charge. There are 6 such sections in total, or cans as they are called. Each section gives a voltage of approximately 2.1 Volts, if you multiply by “6” - here you have 12.6 - 12.8 Volts.

The structure itself is very strong, but the weak link in this chain is the electrolyte, and in particular sulfuric acid. It is because of this that frequent battery failures occur during deep discharges.

But the second component, , indirectly contributes to failure during overcharging! Because:

• It begins to boil, and accordingly the temperature inside the jar increases, which negatively affects the plates; they can simply crumble.
• It tends to evaporate, which will reduce and negatively affect the plates.

Deep discharge as a battery killer

Well, now that we have remembered the structure, now let’s remember why deep discharge is so destructive for the battery. Here's a very simple situation:

Ideally, the electrolyte density should be 1.27 g/cm3, this is the ratio of water and sulfuric acid. During discharge, sulfuric acid begins to be absorbed from the electrolyte, or rather, it begins to settle on the positive (dioxide) plates in the form of salts. And the lower the discharge, the more they settle on the plates - the density drops completely.

A deep discharge is a kind of minimum possible battery threshold, that is, there is nowhere to discharge further. With this chemical process, sulfuric acid is in the form of salts on the positive plates and in order to remove it from there, you need to charge the battery as quickly as possible.

Then the density will begin to return to its normal course - distilled water will begin to be absorbed from the electrolyte, but the acid concentration will begin to increase.

“So what,” you say, “well, I discharged my battery to zero, then charged it and everything is fine, I’ll continue riding”!

But it’s not so simple - often the concentration of salts on the plus plates is so high that when charging, the salt crystals are not destroyed, but remain! This tells us that the plate is completely covered with salt, its contact with the electrolyte is minimal! This means that it will not work normally and contribute to the accumulation of charge. I know from experience that each deep discharge takes away from 2 to 3% of, and immediately! If you accumulate 10 of them, that’s minus 30% of the capacity, such a battery will no longer start the engine of your car.

So you can lower it to about 11 Volts, this is a kind of minimum limit, after which sulfation of the positive plates begins.

Causes

Now a few words about the reasons. Often these are all kinds of current leaks. For example, on a stationary car, they should be reduced to zero, but if you install non-standard equipment (alarms, radios, other gadgets), they can suck energy from the battery, even while parked. Here's the first reason.

The car's generator may also shut down, that is, it will not work, the car's charge is being replenished - the second reason.

The third is long-term parking, for example six months or a year; if this is not done, the charge may drop to a critical level. In general, you need to start the engine at least once a month to replenish the battery’s energy, and to circulate fluids and oil through its cavities. It is important.

These are probably the main reasons, of course, unless you sit and specifically drain the battery, for example, with a radio or headlights.

Consequences

As I already wrote above, they discharged deeply several times and that’s it! The battery can be thrown away! The positive plates will be completely covered with salts, the density of the electrolyte will drop and will not increase. Even if you replace the electrolyte with a new one of the required density, it will not wash away the formed salts.

As many battery manufacturers assure, the maximum threshold value is 15 - 20 cycles. But I know from experience that after 10 cycles, such a battery cannot cope with its duties in winter; it will still work in summer.

The moral of the story is - do not allow such deep discharge parameters. This really kills your battery, each time you take away about 3% of the capacity.

Is it possible to restore?

In our world, everything is possible, but at what cost! Ideally, you need to remove the salts from the plus plate, how to do this?

• In case of strong crystallization, physical removal is possible. To do this, you need to remove the plate pack and clean it of salts - then fill in new electrolyte and charge the battery. Is it difficult to do this? YES of course - YES! How do you get a package of plates? You will need to cut the plastic on top and physically pull it out. Then clean each plate separately - this is really difficult to do. Although I have a video somewhere on YOUTUBE, it didn’t really indicate whether the battery then worked or not.
• Of course, now there are a lot of so-called plate desulfators, that is, such chemical liquids remove this deposit of salts, but I will have a separate article about this, here, too, not everything is so simple. Many write that it is simply a miracle, while others never use it. But ideally, the container is also restored and excess salts are removed.

If your car's battery is completely dead, don't panic. There are several simple ways to solve this problem. In the lives of many drivers, there has been a situation when, when trying to start the engine, the starter emits a slow “grumble” or simply clicks from the starter relay, but the starter itself does not work. The low battery is also confirmed by the dim light of the dashboard; it begins to flash when you try to start the engine. This indicates that the battery has simply used up its charge and cannot provide the starter with the necessary amount of energy to rotate the crankshaft.

If you have enough time and nowhere to rush, then it is best to provide conditions for recharging the battery, and then start it and go on about your business. However, as usually happens, the battery discharges precisely when the machine is really needed. A dead battery is not a hopeless situation; there are several methods for starting the engine even with a severely discharged battery.

1. Short circuit in the wiring.
2. Incorrect battery operation.
3. Electrical equipment included.

Usually the problem arises from driver forgetfulness. He may leave the backlight, radio, or interior lighting on at night, or he may not close the door; he also often leaves the heated seats on in the winter. In the morning the driver finds out that the battery is completely discharged. Another reason could be negligence. While resting, the car owner listened to music for a long time, and was sure that the battery capacity was enough to start the engine. As a result, the car will not start.

Often a problem with the battery occurs in winter if the battery has already served a lot of time. An unprepared battery for cold climates can further worsen the situation. If you don't maintain it and never charge it, it will eventually just run out of charge.

It should be remembered that the battery is subject to slow wear and tear, and the capacity decreases every month.

It is worse if it is discharged due to a short circuit. This will not only cause it to quickly shrink, but also cause significant damage, which will significantly reduce its service life.

How to start the engine if there is such a problem with the battery, and if there is no way to light a cigarette? Previously, such a problem practically did not arise, since on old cars a ratchet was built into the crankshaft pulley, which was a special attachment with protrusions. There was a hole in the body located in the direction of this ratchet, and in the trunk there was always a “crooked starter” in the form of a bent handle. With its help, the driver could spin the crankshaft and start the engine.

Modern cars no longer have such a starter in their kit, although sometimes it would be very useful. Domestic drivers have Russian ingenuity, and have already come up with a lot of other methods, which we will tell you about.

There are many different ways to start the engine with a dead battery, so don't worry too much in this situation. However, this is influenced by the design features of the car. To start a car engine, you can use the following methods:

1. By towing or pushing.
2. With the help of "lighting".
3. Start-up charger.
4. Using "fast charge".
5. Spinning the drive wheel.
6. "Drunk battery."

Starting the engine "from the pusher"

The most popular method of starting a car engine is “from the pusher”. It has been used by drivers for decades, and does an excellent job of starting the engine. Its essence is to rotate the engine crankshaft through the transmission, pushing the car along the road with the gear engaged, or using a cable to tow it with another car. Next you need to proceed as follows:

1. Before towing or pushing the vehicle, you must engage second gear or reverse gear. The main condition here is a non-slip road surface, otherwise you will not be able to start the engine.
2. Turn on the ignition, press the clutch pedal and you can start moving by giving the command.
3. After gaining speed, you must sharply release the clutch pedal. Through the drive wheels, the transmission will begin to spin the engine crankshaft. When the engine starts and starts running smoothly, you need to press the clutch pedal and use the gas pedal to regulate the engine speed so that it does not stall.

Now let's look at some features of starting the engine "from the pusher". Most likely, in winter, on a slippery road, you will not be able to start the engine, unless of course the wheels are without studs. The grip of car tires on the road is low, and when the speed is turned on, they will slide on it. Towing in this case is a more acceptable option, but you will have to pull the car longer to get the wheels to rotate.

This method is not suitable for cars with automatic transmission. Although it is also not always possible to push-start fuel-injected cars. However, in an urgent situation this is allowed.

Starting the engine by "lighting"

The most acceptable option for starting the engine in urban conditions is the “lighting” method, since it is suitable for any car, and besides, in the city you can quickly find someone to “light”. The essence of this method is to use the charge from another charged battery. To implement this method, you must have special powerful wires in the trunk, equipped with power tips - “crocodiles”.

Procedure

1. Find a car for “lighting up” with a well-charged battery, and ensure that it is driven closer to your car so that the starting wires are long enough.
2. Turn off the ignition on both cars. Connect two batteries together using cigarette lighter wires and clamps. In this case, there is no need to disconnect them from the vehicle’s on-board network. An important point is to maintain the polarity of the wires: connect the plus to the plus, and the negative pole to also connect to the minus of the other battery.
3. Start the engine of the donor car.
4. Start your car's engine and let it run to provide at least a small charge to the battery from the alternator.
5. Stop the engine and disconnect the wires.
6. Try to start the engine from your battery, which has received a small charge. If the launch fails, the procedure will have to be repeated. It is not recommended to start the engine with a discharged battery if the donor engine is running. This contributes to the failure of some elements of the donor's electrical equipment. It is better to start a diesel car from a diesel car, but a petrol car can be started from any car.

This method can be considered universal, as it is suitable for any car and with any gearbox. The only difficulty is finding a car from which you can “light up”.

ROM is a special device for starting an engine with a discharged battery. It can be standalone or networked. The essence of the method is similar to the “lighting up” method, only the device we are considering serves as a donor. This method is the most effective and convenient, but such a device is not always available. Therefore, this method is suitable for those who have such a starter-charger.

Fast charge

This method is suitable when you have a charger with adjustable current. The battery must be charged for 15 minutes with a high current not exceeding 10% of the battery capacity. If, for example, the battery capacity is 55 ampere-hours, then you need to supply no more than 5.5 amperes of current.

Procedure

1. Remove the battery from the car.
2. Place the battery on charge and configure the necessary charging parameters. In this case, you should unscrew the battery plugs, as a boiling process will occur.
3. Wait 15 minutes and disconnect the charger.
4. Install the battery on the car.
5. Start the engine.

This method is more effective, but for the battery it negatively affects its service life.

Spinning the drive wheel - the “sling” method

Spinning the wheel with a “sling” is an original method that replaced the manual starter. Its essence consists in manually spinning the crankshaft, but through the transmission.

Procedure

1. Raise the drive wheel with a jack.
2. Engage fourth gear.
3. Wrap a rope, tow rope or sling at least five meters long around the suspended wheel. In this case, the rotation of the wheel should be in the direction of movement of the car.
4. Turn on the ignition.
5. Pull the tow rope sharply, spinning the wheel.

After this, the car engine should start, but there are some special features:

• In winter, this method is not suitable for a cold engine.
• The method can be used for engines up to 1.5 liters.
• You can start the engine this way only with a manual transmission.

For diesel cars, as well as with automatic transmission, this method is not used. Some experts claim that there is a similar method for starting the engine of a car with an automatic transmission, but it needs to be done a little differently. To do this, it is recommended to remove the drive belt from the crankshaft pulley and wind a rope around it, which you then pull.

In fact, this is stupid, since the removed belt powers the generator, which charges the battery and provides power to all the electrical equipment of the car. If the battery is discharged and the generator is turned off, the engine will not be able to start, since there will be no electricity to operate the electrical equipment. The whole point of starting the engine with a discharged battery comes down to connecting the on-board network to the generator.

Starting the engine with a “drunk battery”

Launching in this way is used when other methods fail. After this method, the battery will have to be replaced with a new one. But if there is no other way out, and you have an alcoholic drink with you, then you can start the engine.

All the work consists of pouring liquid containing alcohol into the battery. You can consider dry red wine, preferably without sugar. You need to pour 30 grams of wine into each jar. The electrolyte actively reacts with alcohol, as a result the voltage increases and the battery resistance decreases. This voltage should be enough to start the engine.

After this, the battery is significantly damaged and can no longer be used.

If the battery is dead and the car does not open

Electric car door drives have become familiar to us. The doors can be opened by pressing a button on the key fob. What if the battery is dead? There are several ways to do this without damaging the body. Each method requires a special tool, so the method is selected depending on the situation.

Types of methods

• With a key. Many drivers are so accustomed to buttons that they have already forgotten about the existence of a key. But if the door has not been opened with a key for a long time, the lock cylinders may oxidize and prevent the key from being turned.
• By connecting to the generator terminal and a charged battery to ground. But the hood is closed, so you have to connect the wires from below.
• By pressing the door frame with a special device. The door is then opened with a long steel hook, inserted into the gap between the post and the door frame.
• Lowering the door glass. If the car has mechanical windows, you can try to lower the glass by hand. This is done without tools, just with your palms. If you manage to lower the glass until a small gap appears, then there is no need to prompt further.
• If the hood cable is under the fender. The car is jacked up and the fender liner is removed. Then you need to feel the cable with your hand and pull it until the hood opens.