How to properly charge a car battery without removing it from the car

While the car's power plant is idle, the power on-board network  is carried out from an external power source - a car battery. Also, through the power of the battery, the launch of the power plant is also carried out.

Need to properly charge the car battery

But the rechargeable battery does not produce energy for powering the network, it only stores it in itself, if necessary it gives up, then restores its charge from the car's generator.

The cyclicity of the charge-discharge does not benefit the battery itself, in due course its charge decreases, that is, the battery is quietly discharged, it is not possible to completely restore the amount of energy from the generator, eventually the battery charge will not be enough to start the motor. In this case, the question arises: how to charge the car battery.

Charging is performed by this operation. But before describing how to charge the car's battery, we will understand what kind of batteries are, their main parameters that are taken into account when charging, types of chargers, the principle of their functioning and how to properly charge car battery  and what not to do when performing an operation.

Video: Battery explosion

All batteries are structurally similar. There is a set of plates that play the role of electrodes, some - positive, others - negative. In order for a chemical reaction to occur between the plates, as a result of which electricity is released, the space between the plates is filled with an electrolyte. Depending on the type of battery, either an acid solution with water or an alkali solution with water acts as an electrolyte.

Types of batteries

The following types of batteries are used on cars: acid, alkaline and gel. There is one more type of battery - lithium-ion batteries, but due to their peculiarities, the battery data can not start the engine, so in cars they are used so far only as an additional battery.

In acid batteries, the electrodes are made of lead, in which there are additional impurities. Lead, as a material of electrodes, is used because this material has a good energy intensity and can produce currents of large values ​​in a short time. The electrolyte of these batteries is an acid solution. These are the most common batteries that are used on a car.

Alkaline batteries have not lead, but nickel-cadmium or nickel-iron plates. And the space between them is filled with a solution of caustic potassium. These batteries on passenger cars are not often used, because they have lower current strength than acid batteries.

Gel batteries appeared relatively recently. In fact, this same acid battery, only its electrolyte is brought into a jelly-like state. These batteries are promising, but a number of technological features of these batteries do not allow them to be widely used, and they are not worthy.

In addition, the battery is divided into serviced and unattended. Acid batteries are only serviced. And all because during the chemical reaction part of the water from the solution evaporates. In order for the electrolyte to have a suitable density, periodically it is necessary to check the state of the electrolyte and, if necessary, add water.

Water for refilling in the battery is used only distilled.

Maintenance-free gel batteries. They have a sealed enclosure. The chemical reaction does not evaporate the water. Therefore, does not require a refill.

Types of chargers for charging the battery

In the future, we will consider how to properly charge a car battery using the example of a common acid battery. But while we go through the chargers.

Any charger is an electrical converter. The most simple circuit  charger (ZU) - this is a transformer reducing and a diode bridge. The principle of operation is as follows: AC voltage 220 V, passing through the transformer and the diode bridge, is converted into a constant voltage of 14-16 V, which is required to charge the battery.

Often, the design of the charger includes additional control sensors - ammeters and voltmeters, voltage and current regulators, fuses. Although there is a charger, in which the current and voltage for each battery are selected in automatic mode.

Features of charging the car battery at home

Before you charge the car battery at home, you should consider several options for charging the battery.

• The most optimal current for charging the battery is the figure of 10% of the nominal battery power. That is, with the indicator of the energy capacity of a battery of 60 Ah the current should not exceed 6 A.
• The optimum voltage at the memory terminals is + 10% of the nominal voltage of a fully charged battery. For example, for a fully charged battery, the voltage across the terminals is 12.6 V. 10% of the rated voltage is 1.26 V, we add it to 12.6 V and get an optimum voltage of 13.86 V.
• Conduct fast charging  battery is possible. Such charging is performed by currents of large values ​​- 20-30 A. But such charging damages the battery, therefore it is better to abstain from such charging.
• When charging a gel battery it is important not to exceed the critical voltage for such a battery, which is usually 14.2 V.

These are the main criteria that are taken into account in order to properly charge the car battery. Let's go directly to how to charge the car battery.

Preparatory work to properly charge the battery

First you need to make sure that the battery is really dead. To do this, it must be removed from the niche in the car. In addition to the natural discharge of the battery due to its operation, the cause of discharge can be damage to the battery case, resulting in the electrolyte leaking and the chemical reaction in it does not go away. Therefore, after removing it, it is necessary to clean it from dust, dirt and carefully inspect the battery case. If a crack is present and an electrolyte has leaked out of it - such a battery can not be used further.

Determine whether the battery is discharged, you can by the color indicator, which is often installed on the housing cover. Colors in the indicator may be different, so you should pay attention to the sticker with an explanation, which is usually pasted next to the indicator.

You can check the status of the battery charge by the voltage on the terminals. To do this, you can use an ordinary tester. With a discharged battery, the voltage will be lower than the rated voltage.

Before you charge the car battery, you should also check the electrolyte. Through the filler plugs you can follow the condition and the amount of electrolyte, in the normal state, the electrolyte must be clean, transparent and free of impurities, and its level should be above the plates. At a lower level, you need to top up the distillate.

You should also check the vent in the battery cover. It should not be clogged, otherwise there will be no escape for evaporation.

How to properly charge the car battery at home?

You can then directly charge the battery. An important point is the evaporation of the electrolyte when recharging, so do not do it in a residential building. Also, first connect the charger to the battery, and then to the network. Care must be taken to ensure that the charger is correctly connected to the battery, otherwise the charger fuses will fail if the connection is incorrect.

  Video: How to properly charge a car battery

Charging the battery charger  is produced by two methods:

1. with the first method, charging is performed at a constant value of the voltage, usually this value is 14-16 V. And the current strength is a variable value. At the beginning of charging, the current is large, it can reach 25-30 A, but as charging, the current decreases.
2. in the second method, the current is constant, and the voltage varies. This method is more complicated, and you need to fully know how to properly charge a car battery with such a charge.

Correctly charge the car battery with a charger, which uses the method of constant voltage - it's easy. It is enough to set the regulator current at the level of 10% of the energy capacity of the batteries. As the charge is recharged, the current will fall. The signal that the battery has completely restored the charge will be the dropping of the ammeter needle to "0". Usually it takes 10-13 hours to fully recharge with this current.

Charging by a device using the direct current method is more difficult, and you need to know how to recharge the vehicle's battery with such a memory. Since this device has a current parameter set, the current is initially set at 10% of the power consumption.

With this current, the battery is charged to a voltage of 14 V, after which it should be reduced by half and charged with this current to a voltage of 15 V, after which it is still necessary to reduce the current by half. The signal of full charge of the battery will be keeping the voltage indicator at the same level in the indicator for an hour.

After charging, if possible, check the voltage at the battery terminals by applying a load fork. If it does not, make sure the battery is fully charged by installing it on the car. The charged battery should "cheerfully" turn the starter and start the power unit. In principle, that's all you need and it's important to know in order to properly charge the car battery.

A rechargeable battery is the only source of electricity in a car. If the old domestic machines could be started with a "pusher", then with foreign cars this trick unfortunately will not work. All due to the fact that some models do not have the door to open without electricity. It is worth knowing that the battery is used:

• to start a car;
• for feeding the systems of braking and regulation by the car;
• in the process of adjusting the amount of fuel.

Periodically you will have to change this object, but you can save a significant amount by charging it at home. Unfortunately, most motorists do not know how to properly charge a car battery with a home charger.

Preparatory work

When embarking on such an important process, do not forget about security measures and preparatory work. Many newcomers ask me if it is necessary to get the battery out of the car before charging it. In this situation, you can pull out, and you can leave it there. But it is better to put such a keeper of energy in the garage, where the temperature fluctuates within 10 degrees of heat. If more, it is fraught with explosions, which periodically occur due to the activity of the electrolyte.

  I have an air conditioner in the garage, so it's easier for me. I expose the temperature regime to 3-5 degrees. I note that the frost during charging is not particularly terrible. But on the street there are frosts up to - 15 - 20 degrees. Under such conditions, we risk damaging the battery and the charger.



If you decide to shoot it, then consider that when charging it releases harmful toxins. Do not put it in the apartment for a long time. It is better to use a garage or at the very least a balcony. Plus, all the climate control settings, air conditioning, speaker system and other devices - will fail, and you will have to spend extra time on reconfiguration.

But, if you load it, not getting out of the car, then all actions should be done in a dry and warm place, for example, in a heated garage. At the same time, the entire machine must be heated to room temperature before charging.

  There are several charging methods. The first is charging using DC. In this case, constant voltage monitoring is required. For example, for a battery in 60A, I use a current of 6 amps for 20 hours, and then reduce to 3 amps, and when the voltage reaches 15V, then the current must be 1.5A. This method is capable of a long time to charge the equipment, but the disadvantage is that it is required to constantly monitor the process, in addition, harmful gases are released.

The second option is charging using DC voltage. It is considered the safest way and does not require special monitoring of the process. The battery charge level directly depends on the voltage value. The only downside is that the time of charging from an ordinary outlet will be great.

  There is also a combined method. It is fast and, at the same time, safe. Most motorists use it. First, charge the device direct current, later - constant voltage. Many modern sources of electricity are produced precisely under this method of charging.

The express method is used for urgent recharging. To do this, remove the terminals, clean them, connect them with the correct polarity, and put the current at the maximum level. Wait 20 minutes, and install the battery back. This method spoils the battery with frequent use and is ineffective if it is discharged by more than half.

How to act

I suggest that you familiarize yourself with the step by step plan of charging the battery.

1. Disconnect all equipment. First remove the negative terminal, then the positive one.
2. If the battery is secured with straps, unscrew it. Do not overturn it to prevent electrolyte from flowing.
3. Place the battery on a firm and level surface near the 220V outlet. It is advisable to work in a well-ventilated room.
4. If you recently bought such a source of energy, then it should be accompanied by an instruction. You will learn about it and observe everything strictly.
5. If there is a lack of liquid (it is shown on a special plate), fill with distilled water. But this is only required if there is such a bar (and it does not exist on all models).
6. Connect the terminals from the charger, and plug the battery into an outlet. Some chargers show the level of charge and there is a power regulator. In other situations - check everything with a voltmeter.
7. After carrying out this procedure, remove it and install it in the machine.

  I described all the ways and the whole turn-based recharging plan. You can carry out this procedure at home or in the garage. If you do not understand something, then look at the end of the video how to properly charge the car battery. I hope all of the above I will help you.

Usually batteries last for several years. It all depends on the operation of the car. If you are a fan of listening to loud music without the engine turned on, it's no wonder that you often have to "add" energy. I have a battery on the domestic car for 7 years without a single charge. You can not believe, but I will say that the radio was not installed inside.

There are several main reasons that lead to rapid discharge and wear of the battery. First of all, this is a failure to comply with the temperature regime - intensive operation at a temperature of more than + 40 ° C or less than -25 ° C. You will need to charge the car battery after a long period of storage in a discharged state. Also, incorrect recharge modes will significantly shorten the operating time:

• frequent short-lived;
• single long;
• constant undercharging.

  The result is a critical change in the density of the electrolyte, which leads to loosening of the active mass (the substance pressed into the lattice of battery plates) and its shedding. This process is called battery sulphation.

  Modern devices can correctly, automatically charge the battery at home, even without removing it from the car. This is done in several ways:

• stepped circuit;
• impulse circuit;
• reversible scheme;
• combined circuit.

  However, all of them are based on two principles - it is necessary to correctly charge the battery with a constant stabilized voltage or with the stabilization of the current strength.

Determination of the degree of reduction

Correctly charge the lead-antimony serviced battery by a current strength of 1/10 of the nominal capacity. With this method, the efficiency is much higher, since most of the surface of the active mass is activated, but also the charging time is substantially increased. The current degree of charge should be checked at a temperature of about + 150 ° C, by an aerometer measuring the density of the electrolyte. A special set of car enthusiasts, which includes an aerometer, a flask and a pipette for collecting liquid. They can check the density of not only the electrolyte, but also the antifreeze. Degree of charge maintenance-free battery  can be checked using an electronic voltmeter. We connect in parallel: plus to plus, minus to minus. The voltage across the battery terminals must be measured to the nearest hundredth. There are special car voltmeters connected to the cigarette lighter, which allows you to instantly check how many volts the battery produces at the moment, without removing it and even opening the hood.

Degree of charge,%	Battery voltage, V
100	12.71
90	12.57
80	12.47
70	12.37
60	12.29
50	12.25
40	12.13
30	12.05
20	11.99
10	11.95

Charging time

  First, you need to find out what capacity you need to give the battery. It is determined by the formula: S = C × (1 - Cs / 100), where S - battery charging capacity in Ah; С - nominal capacity in Ah; Cs is the real charge in%. Thus, for a battery with a capacity of 60 Ah, discharged to 40%, the charging capacity will be: S = 60 × (1 - 0,4) = 36 Ah. If charging at home is carried out by a device with current stabilization, it is necessary to apply 6 A (1/10 of nominal) to properly charge the battery. Considering that during operation the efficiency of charging falls by approximately 20% per year. The battery that has been working for 3 years will be spent time: T = S / (Isar × 0.6) = 36 / (6 × 0.6) = 10 hours. You can use the charger, stabilizing the voltage. This circuit is mainly used for charging non-serviced batteries. The charged battery is supplied with a stable voltage of 15 V. The primary current is 1/10 of the capacity. In the process of charging, it will decrease, due to the increase in internal resistance, and stop at 0.2-0.5 Amp. The charging time can be from 15 hours to 24 hours.

Safety regulations

  Charge the serviced battery at home in a well-ventilated room, as this process is accompanied by the release of oxygen-hydrogen mixture. For the same reasons, it is not allowed to smoke near the device and allow open flames or sparks. The surface of the battery is cleaned of dust and dirt. The contact terminals are cleaned to a shine. The plugs of the sections are unscrewed (in the serviced) and the ventilation holes are cleaned.

IMPORTANT! When cleaning, do not use rags or rags made of man-made fibers, since a spark may form.

Depending on how much electrolyte is left, add the required amount. Otherwise, the antimony mixture will fall off the lead plates, causing the battery to become unusable.

Charging device

  When choosing them, you should pay attention to three main factors.

Charging method

  Constant current strength will quickly, correctly and completely restore the battery, but there is a risk of boiling the electrolyte in the final stage of the process, which somewhat shortens the life of the batteries. The DC voltage does not require monitoring, but it will take a long time to charge and the battery capacity will not recover completely.

Type of connection

There are devices that work from the usual household network and portable, capable of charging the battery from the cigarette lighter. The latter can charge the battery in a few hours, but require constant monitoring of the process, since there is a danger of overheating the electrolyte. Start-up device Black-Decker BDV030, with connection to the cigarette lighter. It gives an opportunity to make an express charge, without removing the battery from the car. An example of a combined device that stabilizes voltage and current strength can be the Tornado model.   The charging process is performed in semi-automatic mode. After the preliminary calculations, the starting current is set. This model is adjustable up to 6 amps. During charging, the current and voltage values ​​are automatically reduced, protecting the battery from overload, and the electrolyte from overheating. The indicator located on the front panel shows how much energy is currently consumed.

Restore the nominal capacity

  In the process of operation, even the correct systematic recharging does not exclude natural sulfation of the plates as a result of aging. This reduces the capacity of the batteries. There are several simple ways to restore it. The most effective scheme involves a complete recovery of the active mass by chemical means. The battery must first be checked for continuity and charged to its maximum current value. The electrolyte is drained and disposed of. A solution consisting of distilled water, 5% ammonia and 2% trilon B (ETHYLENDIAMINTETAUXOXIDE SODIUM) is poured into the jars. The process of desulphation should be checked - the reaction should be accompanied by the release of gas and the appearance of small sprays on the surface of the solution. The duration is 40-60 minutes. After completion of the reaction, the battery is rinsed with distilled water 2-3 times. The electrolyte is then filled with the required density. And correctly charged to the nominal values. Watch the video

Description of the question

Installed in the car battery, like all other batteries, requires periodic recharging. Usually, when the engine is running this function is successfully performed by the generator, but there are cases when the battery charge is not enough to start the engine. This can happen if the battery has not been used for a long time, and if the battery is depleted due to the electrical appliances left on. A discharged battery does not usually give out more than 11 volts, so if you find that this figure has fallen, then you need to immediately recharge the battery. How to do it yourself - read on.

Step-by-step solution

1

Consider the option of recharging a conventional battery. In my case it is a battery of the mark "Acom 55", nominal at 55 amperes / hour and with force inrush current  at 460 amperes. The nominal voltage on the battery terminals is 12 volts.

2

  As a source of replenishment of the energy reserve of the battery, in the example above, the Orion PW 325 charging and starting device was used, which can also be used as a power source for other, including domestic purposes. The principle of operation with other chargers is no different.

3

  As a rule, the plugs that close the throat data before being recharged are unscrewed and installed directly on the necks in an unscrewed form. This eliminates the splashing of the electrolyte when it "boils" during recharging the battery.

4

To recharge the battery, you must connect the charger terminals to the corresponding battery terminals, observing the polarity. In this case, the device itself should not be included in the 220 volt network. Usually, the minus terminal is firstly connected, but the priority of a large value when the device is turned off for recharging has no effect. After this (or before this), it is necessary to unscrew the plugs of the necks for the electrolyte (see step 3).

5

Before switching on the mains, it is necessary to reduce the current supplied to the battery from the charger to a minimum level. In the example shown, this is done by scrolling the corresponding adjustment knob counter-clockwise (see step 2). It should be noted that the current indicator shows the actual value only when connected to the battery.

6

The current required to recharge the battery is a tenth of the ampere / hour, that is, the battery rating. In the example, the corresponding value is 5.5 amperes, since the nominal value is 55 amperes. At the same time, the recharging time on such a current using the charging-pre-start automatic device will be about 12 hours. The battery can be recharged at low currents. In this case, the recharge time of the battery will increase in proportion to the reduction of the current, that is, the battery will need to be charged at 2.5-2.75 amps for 20-24 hours. In the event that you have instructions for using the battery and the charger, it is recommended that you follow the data indicated in them.

7

At the end of the recharging time, you must first disconnect the charger from the 220 volts network, and then remove the clips from the battery terminals. The voltage on the battery terminals should be at least 13.5 volts. Do not try to measure the current at all, because the risk of injury is high.

The first circuit to be closed, when the ignition key is turned on when the vehicle is started, is the connection between the battery and the ignition system.

If a weak current flows through this chain, the starter will not have enough power to turn the motor shaft, set the pistons in motion, that is, the engine will not start. The most likely answer is that the battery has been discharged.

What is the battery, device, principle of operation?

Battery – autonomous source  power, capable of accumulating and giving electricity. It is a set of plates placed in separate compartments, banks. The electrochemical bond between them is carried out by means of an electrolyte filled in cans. The electricity is removed from the positive and negative electrodes.

The most common are lead-acid power supplies.

Metals used  - it's lead and its dioxide. Sulfuric acid is used as the electrolyte.

Electricity generation is based on the interaction of lead oxide and sulfuric acid solution when connecting an external load to the electrodes. In this case, the oxide is oxidized to lead sulfate, the consumption of the acid takes place with conversion to water.

This process leads to a drop in the density of the electrolyte, which causes a decrease in the removal of electrical power from the power source, - the battery goes into a discharged state.

To return to the reverse state from the electrodes, it is necessary to remove the load and apply current in the reverse direction, that is, put the battery in the charging state.

Symptoms of the discharge of the power source

There are several characteristic signs that the power supply does not work at full capacity:

• slow "sluggish" operation of mechanical devices, the light from the headlights becomes dimmer than with the engine running;
• at start the starter began to turn more slowly, it takes more time to start the engine;
• at start-up, a characteristic sound is heard, coming from the operation of the starter, clicks appear, the indicator lights on the panel do not burn constantly, but flash in time with snapping;
• at visual inspection is revealed, that the color of the liquid acquired a dark reddish hue.

Preparation for charging and safety regulations

Charge the battery is most convenient in a closed room with a positive temperature, - in urban conditions, this is a garage or your own home.

Before loading procedure it is necessary:

• remove the power source from the car and bring it into the house;
• in case the case occurs in the cold seasona, the device must be kept for several hours to receive a positive temperature;
• conduct an external examination procedure for possible mechanical damage, - this may be a consequence of leakage of the electrolyte, then it is necessary to dispose of the battery and purchase a new one;
• clean the body of mud and salt deposits;
• clean electrodes, - during operation, the metal is covered with a layer of oxides, which increases the electrical resistance.

The power source itself is a subject of increased danger due to the presence of acid in it. Another danger lies hidden in the charging procedure itself. This is due to the fact that during the course of electrochemical reactions, the release of harmful gases is taking place.

It follows that it is necessary to take a number of security measures when charging a power source at home:

1. Ensure ventilation of premises, especially where the battery is located.
2. If there is a balcony, it is advisable to transfer the process of charging the battery to it.  At the same time, the balcony door leading to the living room must be closed. On the balcony itself, it is necessary to provide ventilation by opening the transoms or the ventilation pane.
3. The facts of bad health - headache, nausea, perspiration in the throat, difficulty breathing - are evidence that the room is saturated with harmful gases, the human body is poisoned. In this case, the process of the charge must be urgently interrupted, to ensure intensive airing of the premises, - to arrange a draft.
4. Another sign of deterioration of the microclimate  - this is the behavior of pets that begin to show concern, voice sounds, "stick" to the owners.

Checking the density of electrolyte

An important preliminary procedure for preparing for charging a power source is to check the electrolyte:

• The battery caps are removed from the battery and the electrolyte level is visually monitored  - in normal working condition, the liquid must completely cover the lead grids. Otherwise, add distilled water.

Important! Use only distillate. Water, poured from the tap or taken from other sources, contains physicochemical impurities that will cause the battery to operate abnormally and lead to the rapid destruction of lead plates.

• The density of the electrolyte is checked by means of a hydrometer- device with glass casing  with the scale applied. The density level will show the float inside the device. To do this, using an integrated pear, the electrolyte is taken. The standard density is in the range 1.25 ... 1.29 kg / dm³ at a temperature of +18 ... 25 ° C.

Important! Sulfuric acid is a chemically aggressive reagent that corrodes tissue that causes burns. When working, you should take care of rubber gloves and goggles.

Charging process

Charging is required to complete the charging procedure.

The market now has a large number of models used to work with lead batteries, but they can be grouped into two groups:

1. A device with a constant current of charge, - supplies a constant current.
2. A device with a constant voltage,  - the charge process occurs at a constant voltage value.

For the charging procedure, the current strength is an important indicator.

Charging current

1. The first way , - the power source is charged from the device with a constant value of the output current. In this case, a value equal to 10% of the rating value of the battery capacity is adopted. For example, for a battery with a value of 55 units, the current will be 5.5 amps.
2. The second way , - the battery is supplied with a constant voltage. In this case, the voltage range will be 14.5 ... 16.5 V with a gradually varying value of the current strength of 45 ... 20 A.

Proper charging of the battery

Before starting the charging process, you must:

• Gently wipe the battery case, especially at the top, near the lids.
• Remove the covers without removing the faroh, but leaving everyone next to his jar.
• To set the "zero" indication of the charger or, in more sophisticated chargers, set the desired charging mode.
• Connect the battery to the charger.

Important! The connection sequence should be just this:

1. first connect the terminals to the electrodes of the power source in accordance with the polarity;
2. further, the charger is connected to a stationary power network.

• The required level of current or voltage is adjusted.

Sequence, charge control of battery under different modes

1. The first way - charge by direct current, will require constant attention to the charging procedure. This is explained by the fact that as the degree of saturation increases, the initial value of the charging current proves to be superfluous, - part of the energy is expended on the electrolysis of water, which decays, forms oxygen in one electrode, and hydrogen in another. Due to this, during the whole battery charge period, it is necessary to periodically change the current indicators to a smaller side.
2. The second way   - charge by constant voltage. During the charge process, the voltage value remains constant, but the current strength at the end of the procedure comes to naught. The amount of generated gases is minimal, which makes it impossible to control the entire process all the time. With an initial voltage of 16 ... 16.5 V, a fully charged battery will be fully charged after 24 hours.

Council. If possible, it is better to purchase a modern charger, which, despite the higher price, allows you to monitor the charging process in automatic mode, changing the output in accordance with the degree of charge of the power source.

Check of working capacity of the storage battery

An indication on the charger will indicate that the battery is fully charged, but the actual operation of the power supply can only be shown by operating tests, for example, by means of a load fork.

Load fork  Is an electrical device that simulates electricity consumers in a car.

It is supplied with a measuring instrument. When connected to a fully charged battery, indicators for 5 ... 10 seconds should be not less than 9V, equal or increase.

Otherwise, lower values ​​or their drop indicate a battery malfunction.

1. Tip 1. If there is an urgent need to charge the battery, it is possible to apply short-term enhanced mode. For this, large current values ​​are used.
2. Tip 2.  To prolong battery life, it is better to use smaller values ​​of charging currents, but the battery charging time can increase for a day, two or three.
3. Tip 3. In winter, it is necessary to recharge the battery when the discharge level drops to 25%. A larger discharge will cause a longer charging procedure.