The battery may fail for a number of reasons. It is possible that there is a leak somewhere in the electrical circuit. But it’s more likely that you simply forgot to turn off the headlights or radio at night. This option is also common: the car was not used for a long time and did not start, it was parked in an unheated room, so the battery lost its charge. There are many ways to “revive” a car, and the most common is to ask for a “light.”
Not all car enthusiasts know how to determine what is the reason for a car’s failure to start. To confidently say that the problem is in the battery, you need to pay attention to the following details. First, when igniting, check your dashboard lights. If they light dimly, this indicates a low charge. Secondly, listen to the sound of the engine. It should be fast, not stringy and slow. very shrunken, characteristic clicks will be heard from under the hood. Some cars are equipped with a voltmeter. The arrow of the device should not be in the red zone when igniting. Also carefully inspect the battery itself. “Sophisticated” models, as a rule, are equipped with their own charge indicator, so the battery itself will let you know when the charge is low.
In this material we will tell you not only how to start a car with a dead battery, but also how to charge a battery without a charger.
How to light a car correctly
If you are worried about the charge and do not want to be immobilized at the most inopportune moment, get special wires in advance to start the engine. When purchasing, you should pay attention to the packaging, or rather, to the characteristics described on it:
- cross-sectional area of at least 10 sq. mm (thinner wire can simply burn out);
- minimum current strength of at least 200 amperes (more is better, this will increase the efficiency of current transmission);
- wire length is 1.5-2.5 meters (shorter wires are awkward to attach, longer ones have too high resistance);
It is also important to inspect the wire. The braid should be rubber, because plastic does not tolerate frost well and becomes too hard in the cold. The fastenings of the wires to the terminals must be soldered, otherwise the electric current will not reach the terminals. The clamps should be wide and open well, this will facilitate fastening and increase the contact area.
It is also important to choose the right “donor” car.. Its battery must be in good condition, the electrolyte must not leak, otherwise we will have not one, but two “dead” cars. In no case should a 12-volt battery be converted from a 24-volt one. The voltage of the dead battery and the “donor” battery must match. True, a 24-volt battery can be powered from two 12-volt batteries connected in series.
Once you find someone willing to help you, ask them to put the car in a suitable position. The wire should be long enough without much tension. When connecting, it is very important to observe the polarity, otherwise you will not only damage the battery, but also the electrical system of the entire car. The positive wire is usually red and the negative wire is black. Experienced drivers recommend the following connection scheme: first you need to turn off the “donor” car. Next, we connect the plus to your car, and then to the donor. Then we connect the minus to the donor, the last one is the minus to your car. When connecting the fourth terminal, a spark is often knocked out, which is quite normal. It is advisable to connect the last terminal to ground - an unpainted metal part that has good contact with the body.
In modern cars, access to the battery can be difficult; as a rule, there are special places for “lighting”. When all the terminals are connected, you need to start the “donor” car for 3-5 minutes to recharge the “dead” car. After this period, we start the second car and let it run for another 5 minutes. After this procedure, disconnect the terminals from the “donor” and your car. Let your car run for 20 minutes, as charging occurs faster when the car is running. It is advisable not to turn on the headlights and radio, otherwise the whole procedure will probably have to be repeated again.
The video shows charging a car battery:
Features of various models
In addition to the “lighting up” procedure itself, there are other options for igniting a car with. A car with a manual transmission can be started “from the pusher”. Sit behind the wheel and put the gear in neutral. Turn on the ignition by turning the key. After this, the people helping you should accelerate the car to 15-20 m/h. While driving, engage third gear and release the clutch. As soon as the car starts, you should turn off the gear. The main thing is not to turn off the engine immediately after ignition, because the accumulated charge may not be enough to restart the engine. In addition, instead of physical force, you can use a tow rope, but this option, unfortunately, is absolutely not suitable for an automatic transmission.
There is also another method on how to start a car if the battery is dead. With its help, it may be possible to accumulate a little charge for ignition. Try turning on the high beam headlights for a few seconds. This will provoke “warming up” chemical reactions and collect some charge in the battery. The main thing is not to crank the starter for more than 5 seconds at a time, this will cause a final loss of charge.
Alternative charging methods
If you find yourself in a remote area and have no one to ask for help, do not despair. A regular battery with a capacity of a couple of volts will help you. Any device will do: flashlight, cell phone, laptop, but, of course, the battery must be charged. It is necessary to open the hood and find the wire connecting the battery and the generator so that when you turn the key, you can send a signal to the latter. The approximate location of this wire is a light indicating a problem with the battery. The wire will have to be broken and a battery installed in its place. After this, the car needs to be pushed, preferably downhill. While driving, jump into it and turn the key in the ignition. Once the car starts, you can remove the battery without turning off the car.
In an emergency, also try shaking the battery to distribute fluids evenly. The main thing is, under no circumstances try to illuminate yourself with a lighter when you look inside, because the result can be sad.
If you have enough time, but do not have a charger, you can assemble a simple device of this kind from just a few elements:
- household incandescent light bulb with a power of up to 200 watts. The higher the power, the faster the recharging will be carried out, the main thing is not to overdo it, otherwise the battery will become completely unusable;
- semiconductor diode - this component is suitable for conducting electricity in only one direction. It will help convert alternating voltage in the network into direct voltage to recharge the battery. The diode must be large enough, otherwise it may not withstand the applied load;
- wires with terminals and a plug for plugging into a socket.
Video on how to charge a battery without a charger:
When setting up the circuit, the light bulb should be lit at full intensity, because the diode cuts off half the amplitude of the alternating current. If the light does not light, this is a sure indicator that the circuit is not working. It will also not light up if the battery is fully charged, which is unlikely since the voltage at the terminals is high and the current is low. Charging usually takes about 10 hours, do not forget to turn off the power supply after the period expires, it will boil and become unusable.
It would be useful for a car enthusiast to have a device with him to check the battery charge. This extremely useful thing costs around 500 rubles and will help you avoid damage or loss of charge at the most inopportune moment.
The most common lead-acid batteries periodically require recharging from a 220-volt network. For this, various chargers are used. This article will help you determine the optimal charger and create the right charging algorithm that will extend the life of your battery.
How to determine the charge and condition of the battery
There are two indicators of battery charge - and voltage at the terminals. However, these indicators apply only to serviceable batteries in which the lead plates have not crumbled. If the plates are damaged, then the density of the electrolyte and the voltage at the terminals will not say anything about the battery charge. A working battery differs from a damaged one in that it is capable of delivering high current for a long time. Even a weakly charged battery can spin a cold engine for at least one minute. A fully charged battery can spin the engine for at least 3 minutes. Even after the battery has “dead” and is unable to crank the engine, after 3-5 minutes of rest it will again be able to crank the engine without voltage.
The electrolyte density of a fully charged battery must exceed 1.22 grams per cm³. To measure the density of the electrolyte, you need to use a hydrometer, which can be purchased at any auto store. Given the huge number of hydrometer models, it is impossible to give a universal recommendation for their use. Therefore, carefully read the instructions that come with the hydrometer.
The voltage of a charged battery (no load) is 14 volts. When the ignition is turned on, it is 12.5 - 13.5 volts; when the starter is started, the voltage drops to 10 - 11 volts. If the battery voltage is below these values, you need to charge it.
How to charge a working battery using the constant voltage method?
If you use this method of charging your battery, you must ensure that the charger maintains a voltage between 13.8 Volts and 14.4 Volts. Charging is performed automatically: the device independently sets the current, relying on the battery capacity, and changes during the charging process. The charging current should not exceed 10% of the battery capacity. Excessive current will lead to boiling of the electrolyte, a decrease in its level and a drop in battery capacity.
If the AKM is maintenance-free, that is, adding electrolyte to special jars is unacceptable, then it must be charged using a constant voltage method. The charging process will be considered complete when the voltage at the terminals is still 14.4 Volts and the current drops to 0.2 A.
Exceeding the charging current will lead to damage to the lead plates of the battery. Charging is complete when the battery voltage (with the charger disconnected) is 14 volts. Thus, the charging process becomes more comfortable and does not require constant monitoring. The process of gas evolution is completely eliminated, and the electrolyte does not heat up to dangerous temperatures.
Charging time is also determined by the technical characteristics of the battery itself. On average, this figure comes down to 4-5 hours. During this time, the battery manages to charge 90-95 percent and ensures the normal functioning required for operating the car.
If you use a charger without a voltmeter, then charging must be stopped when the charging current drops to 3 - 4% of the battery capacity. Further charging will overcharge the battery and reduce its capacity.
The only drawback of this method is that it is not possible to fully charge such a battery. This is due to the fact that the voltage supplied by the charger does not exceed 14.4 Volts, and the required voltage required to fully charge the battery should be about 16 Volts.
It is worth remembering that the battery is also charged from the generator. This electric machine allows you to start a car when the battery is dead from another source of electric current, for example, from the battery of another car.
How to deal with a discharged or dry battery
Modern chargers have built-in short circuit protection, so charging current begins to flow only after a voltage of at least 8 volts is applied to the electrodes of the device. A completely discharged battery cannot create such a voltage, so the charger will not start charging it. In order for charging to begin, you need to connect the electrodes, and then (observing the polarity) connect a charged battery of any capacity for 1 - 2 seconds.
Before charging a dry battery, you must. To do this, you must first measure the density of the electrolyte residue. If the density is noticeably higher than normal, then it is necessary to add distilled water in small portions (200 - 300 ml), then mix the contents of the battery and measure the density again. After the density has reached the required value, fill the battery with ready-made or homemade electrolyte. The finished electrolyte, as well as the components for making a homemade electrolyte, are sold in a car shop. When mixing sulfuric (battery) acid and distilled water, do not forget that it is necessary to pour the acid into the water. An attempt to pour water into the acid will lead to boiling and strong splashing of the latter. Use a glass container to mix acid and water and constantly check the density. As soon as the density of the solution reaches the required value, pour it into the battery. The electrolyte level should be 1.5 - 2 cm below the top of the battery. Then charge it in the same way as a working battery.
Is it possible to charge a “full” battery?
Many car enthusiasts are familiar with the phenomenon of battery overcharging. It occurs when, for some reason, the voltage regulator starts to work incorrectly, so the voltage at the generator output exceeds 14.5 Volts. The optimal voltage of a fully charged battery is 14 Volts. When the voltage difference between the generator and the battery exceeds one volt, the latter begins to absorb additional energy, which leads to boiling and evaporation of the electrolyte, as well as destruction of the lead plates. As a result, the electrolyte level first decreases, then the battery capacity decreases. After a short time (depending on the generator voltage), the drop in capacity becomes irreversible and cannot be restored by adding distilled water.
If the generator voltage regulator is working normally, then the voltage is maintained at 14 - 14.5 Volts, due to which the battery avoids overcharging. All this fully applies to stationary battery charging, which is carried out using a special charger. If the voltage at the output of the device does not exceed 14.5 Volts, then the battery will take the amount of electricity that is necessary to change the density of the electrolyte. When the voltage of the generator and the charger are equal, the rate of absorption of electricity will drop so much that further charging becomes meaningless. Even if the battery sits on the charger for two days, its capacity and charge will not change. If the voltage at the charger output exceeds 14.5 - 15 Volts, then overcharging will begin, which will lead to a decrease in battery capacity.
If you are using a charger that displays charging current but not voltage, consider the following. The charging current of a fully charged battery should not exceed 1 percent of its capacity. As soon as the charging current has dropped to 1-2 percent, it is necessary to disconnect the battery from the charger to avoid damaging it. Do not charge the battery from a charger without a voltage indicator if the charging current is less than 5 percent of capacity. This will extend the life of the battery and protect it from premature damage.
A fully charged battery can only be charged using a working charger that regulates and displays the charging voltage. If for some reason the charger does not regulate the charging voltage correctly, then connecting a charged battery to it will lead to boiling off of the electrolyte and a decrease in battery capacity. Therefore, it is advisable to postpone charging until the battery is at least 30 percent discharged.
Lighting your battery from another, more live one, is of course the easiest way to help here. However, this question does not arise if there is another car nearby.
- If the battery is dead, then first of all warm it up if it is less than +20 degrees outside. Bring him in warmly. You can warm it up a little on all sides with a hairdryer. This will definitely benefit him. Shake the warm battery several times to mix the electrolyte and wash the plates. The processes in it will begin more actively. Try to start it.
- You can try to revive the car using... a battery. An ordinary battery, say from a flashlight, but of course not a dead one. We park the car on a slope so that we can push it. We find the wire going from the battery to the generator, to the excitation winding. Often in the circuit of this wire there is an indicator (a light bulb on the panel) which signals us about problems with the battery. We break this wire and put a battery in the circuit. Suitable even from a laptop or phone. Now we jump behind the wheel, turn on neutral, let the car go downhill, and when it picks up some speed, engage 2nd gear, turn on the ignition and release the clutch. After the car starts, keep the engine speed a little higher than idle, remove the battery, connect the wire, and insulate it. We put in our dead battery and drive it a little with a generator (this can be done on the go)
- If you have a 220 volt AC source nearby, that is, if you are not in the forest. This method will be somewhat more complicated and more effective. You can assemble a makeshift charging device from a regular 220-volt light bulb, a diode and several wires. Well, of course, this charger will be far from perfect in both voltage and current, but... we have nothing to choose from - there is no charger (as is clear from the question) The light bulb is 100-150 watts better. We assemble the circuit socket-bulb-diode-battery-socket. We charge for about five hours, constantly monitoring the process. If the light bulb is on half-bright, then our circuit is working and charging. I say again - we constantly monitor! Because the battery can heat up and boil.
- Can be recharged using a laptop power supply. We also assemble the circuit - power supply - light bulb from the headlight - battery - power supply. Here diodes are not needed, the unit already produces a constant voltage. This scheme charges a dead battery by 80% in 8-10 hours. And in order for the battery to simply have the strength to start the engine, 30 to 60 minutes of charging is enough (depending on the depth of discharge of the battery)
Well, four more ways to recharge a dead battery without a charger (without a rectifier)
The reason for this article was what recently happened to a journalist on the site, or rather, to your humble servant - a curious episode. About a month ago I bought a middle-aged, but cheap domestic car - as a second one, for slaughter for a dacha construction site.
By the will of circumstances, the car was left for a week practically in the same place where it was bought, and when it was time to move the car to a permanent place of residence, it was discovered that the battery was discharged... It was seriously discharged - the first turn of the key caused a short “whimp” of the starter, the second - a knock of the retractor relay, and the third did not generate even that - only the lights on the “tidy” flickered barely noticeably...
According to the seller, all the electrical wiring of the car was in full working order, the battery was fresh, so it didn’t occur to me to remove the terminal from the battery before idle time. But the interior light remained on, as a result of which the situation turned out to be unpleasant - there were no tools (not even a 10 key to remove the battery!), there were no lighting wires with crocodiles, the car owners whom I approached with a request for lighting the cigarette could not help or they didn’t want to... As a result, I had to turn to the former owner of the car for salvation - fortunately, he lived nearby, and, as it turned out, at that moment he was driving around the area in his new acquisition - a ten-year-old Lancer.
The former owner arrived, but did not bring the cigarette lighter wires - instead, he opened the trunk and took out two dirty and chewed one and a half meter “tails”. One of them was single-core - this is how wiring is done in the walls to sockets, the second was a multi-core cord from an old refrigerator... The cross-section of these “snot” of 1.5–2 square millimeters and the roughly cleaned and darkened from oxides tails did not allow lighting the engine categorically, from the words “absolutely”! However, the situation was resolved favorably - but not at all in the way one might have expected.
The former owner expertly connected the batteries of two cars with these “snots” and, just in case, tried to turn the key - in response, of course, there was not even a click from the starter. After which he winked at me, assuring me that everything would be fine, started his car and relaxed, lighting a cigarette.
My empty battery was charged - the generator voltage was 14.5-14.8 volts - however, as logic and electrical engineering dictate, a completely drained battery would need to be charged in this way for at least several hours! Was my assistant really planning to rattle on until the evening?! This would be quite strange, considering that his wife and child were sitting in the assistant’s car, and we were stretched out, blocking the courtyard passage... However, he was not going to stretch the process to the logically necessary - in no more than 10 minutes (I emphasize - TEN!) the wires were disconnected and wound up, and the first turn of the key started the engine!
What happened?
What happened, at first glance, was incredible... Classical electrical engineering in general and battery science in particular say that a typical lead battery is charged with a current of 10% of its capacity within 10-12 hours. Accordingly, a 55-amp-hour battery, even with a current of 10-15 amperes, had to be filled for at least several hours! However, we “charged” for exactly 10 minutes, and the current clearly did not exceed the above-mentioned value, or even was less - taking into account the thin wires and the disgusting contact of the oxidized wires feebly wound on each other...
That is, it turns out that the effect was not charging, but a kind of “awakening” of a battery that had just fallen into lethargic oblivion. A short ten-minute process could not replenish the energy lost by the battery, but somehow managed to “invigorate” it and helped “mobilize internal resources.” This sounds, I admit, strange: common sense does not approve of such pseudoscientific terminology - “wake up”, “invigorate”... The battery understands only two completely scientific terms - “charge” and “discharge”, and everything else is lyricism...
Mysticism for sale
Lyrics are lyrical, but it is precisely on the above-mentioned effect that Chinese “charging gadgets for blondes” work. Small boxes with a couple of cell phone batteries inside or stuffed with AA format “fingers” - such devices have a cigarette lighter plug coming out of them, and it is through the cigarette lighter that they supposedly charge a dead car battery.
From the point of view of anyone with at least some understanding of electrical engineering, such devices are profanation and deception, but the paradox is that sometimes they are still able to work - in situations similar to the one described above. On a fresh battery – 8-10 volts, on a “magic box” – 12-13. After connecting it to the cigarette lighter, it begins to drive current to the starter battery - the current is weak and completely unable to charge it. But capable of “waking up” and “invigorating”!
Of course, the operation of such devices is extremely unstable, and they will only help if a certain coincidence of factors occurs, which is why they have earned the fair label of fraudulent. But in a number of cases, when the battery itself is fresh and is literally “just about” discharged, even a box of AA batteries stuck in the cigarette lighter can revive it!
What does science say?
Actually, with all the strangeness of what is happening, science must somehow explain it...
– The situation described is neither a miracle nor a hoax.“I know her well,” said Alexander Kazunin, head of the battery laboratory of the Research Institute of Automotive Electronics and Electrical Equipment of the Federal State Unitary Enterprise NIIAE:
– What is happening here is not the effect of charging the battery, but the effect of charging the capacitor - and the battery is also partly a high-capacity capacitor. If a current of 10-15 amperes is applied to a completely discharged battery for a short time, then, of course, a full charge will not occur. But the battery will still gain some energy, enough to start the engine! This is “short” energy, like in a capacitor - it is stored in a discharged battery for a short time. That is, immediately after disconnecting the wires from the donor car, you need to start the engine whose battery you “boosted” - if for some reason you wait 10-15 minutes, this “fast charge” will disappear and the start will fail.
Actually, it is possible to use this method - in other words, to perform “field express charging” from another car using tiny wires, if it is not possible to light it with powerful special cables with “crocodiles”. And sometimes – quite successfully! But it is important to consider two points:
- Successful fast charging of a battery, like a capacitor, is not always possible - it is influenced by the general condition of the discharged battery, the time it stood discharged, and the temperature outside.
- After a successful start using this method, the battery remains empty and requires full charging - either using a charger or a long run along a country road. If this is not done, the next morning there is a high probability that it will not start again!
For a modern phone, the main and decisive criterion remains its autonomy, that is, how long the battery can last without recharging. The worst event for many is when the phone is so discharged that it does not respond to the charger. Why is this happening? How to revive your phone battery?
Causes
Each battery contains a power controller. It is thanks to him that we can see the battery charge percentage on the screen. The same element determines the device’s need to recharge. When the phone is discharged, the controller, after urgent demands to replenish energy reserves, goes into mode to protect the battery from complete depletion.
It is worth noting that the battery is charged through a charger, which has This information contains a way to revive the phone battery - by applying current directly. To ensure that this does not pose a danger to life, there are several simple ways, which are discussed below.
Elementary method
As surprising as it may sound, leave your device charging for a day. For some devices, the push will be one of the pulses received from the charger. Roughly speaking, at some point the battery will “grab” the current and begin to accumulate charge. Don't get mad if your phone responds to the charger with a dark screen. In this case, there is no need to rush. Other methods should be tried only after this method.
Power supply, resistor and voltmeter
For the second, more complex and time-consuming method, a power supply with a constant voltage of up to 12 volts is required. It is better that the voltage is from five or a little higher (it’s safer). You can use the power supply from the router and even the charger from the smartphone itself. A resistor is suitable as an assistant, which is designed for a power of 0.5 watts and a nominal value of 330 ohms.
As for the voltmeter, this is more of a whim than a necessity. So its presence is by no means necessary, although it is very desirable.
The connection diagram is simple to the point of primitiveness: we connect the minus of the source to the minus of the battery, and the plus through a resistor to the plus of the battery. Where is the plus and where is the minus at the source? If you have a charger like a plug from a Wi-Fi power supply, then the plus is the inside of the cylinder, and the minus is the outside. For the USB charging type, you must first do a test with a multimeter. This will allow you to check where is the plus and where is the minus by ringing each channel.
After everything is securely fixed, you need to apply current. If you observe the voltmeter, then you should wait until the voltage rises to 3.5 volts - this is about 15 minutes of continuous operation. This is an ideal method for old-type batteries, but it will also work for smartphones. Again, take your time and remain calm. A mistake can cost your battery life.
Third way
A less time-consuming method for a phone is to use a power supply with a controller designed to restore and charge all types of batteries. Such blocks are used when restoring Ni-MH batteries. This device is similar to the Turnigy Accucell 6. How to use it? The same as with cables in the second method.
It is important with this method not to try to charge the battery completely through this device. Why? Over time, the battery wears out and its capacity decreases significantly. In order not to ruin the battery, charge it through a universal charger up to 3.5 volts, and then through the phone or tablet itself - the device whose battery we reanimated.
Fourth method
In terms of simplicity, this method can be compared with the first. Unfortunately, it does not work on all types of devices, but it does, since it does not require any additional equipment or skills. This way to revive your phone battery at home looks like this:
- Remove the battery from the smartphone.
- Connect the charger to the device.
- Insert the battery into place.
- Leave the phone on charge for 10-12 hours.
Why might this work? As mentioned earlier, the battery needs to be “pushed”. Such a sudden flow of current can become such a shock, and the battery will return to normal, starting to accumulate energy.
A simple battery will help
This method also does not always help, but nevertheless is extremely popular. To implement it, you need to take a fully charged battery or a powerful battery and connect it through conductors, observing the polarity. After ten minutes, you should try to insert the recoverable battery into the phone and connect the charger.
This method is based on the method that motorists use to “light” the battery from another car. And, just like in cars, don’t let anything get hot!
Is it just to revive?
Another, no less strange way is freezing. Some who have already conducted similar experiments with the battery of their device claim that they were able not only to “resurrect” it, but also to increase its service life. The principle of operation of this method is to deceive the controller, which was mentioned above, because at a reduced temperature, chemical reactions in the battery slow down significantly.
Before you restore your phone's battery capacity, make sure it is not a lithium-ion battery. This type of battery may not survive such experiments.
The resuscitation process itself is as follows. To begin with, a battery discharged below the level is sent to the freezer for a period of no more than half an hour. Then charge it for a minute. In this case, turning on the phone is strictly prohibited. Next, you need to remove the battery from the device and let it warm up to room temperature on its own. There is no way to heat or rub the battery.
Once the battery reaches room temperature, it must be placed in the device and charged in the usual way. Such charging can last more than a day, in some cases even two.
What's better?
Before you revive a completely discharged phone battery, you should decide which method is most effective. All these recovery methods are good in their own way, but some are not confirmed to be safe, others require special skill and tools.
In fact, the first and fourth methods are not only ways to revive your phone battery, but also a real guide for an emergency. Such methods will not harm or worsen the situation of the smartphone.
There is quite a bit of controversy about freezing, since low temperatures are what can cause the battery to swell. Some say that this is a way to give a “dying” battery a “painkiller” so that its death will then occur quickly and painlessly.
Even Ni-MH batteries are restored using the second and third methods. But if you do not have access to the necessary equipment and are simply far from electronics, it is better not to risk it and turn to the experts in this matter.
Whatever method suits you, the best solution to the problem is to prevent it. Try to ensure that your smartphone does not turn off because its battery is low. Carry a charger kit or remote battery with you and recharge the battery as needed. Try to avoid friction, shock and large temperature changes - this greatly reduces the performance of the battery and shortens its lifespan.
