Proper battery charging tips and tricks
Proper battery charging tips and tricks

In the first autumn cold, it is necessary to prepare the car for winter. Moreover, this operation includes not only the installation of a winter set of tires. An important aspect is the battery. After all, the quality of starting a car depends on its condition. If the battery is checked in time, problems such as poor starting or a dead battery can be eliminated.


There are several battery charging options:

  • On the car itself with the help of a charger.
  • When removing the battery from the car, in a separate room.
Accumulator charging
Accumulator charging

Also note that the car battery is charged while its engine is running. In this case, a device such as a generator is involved. It is he who generates the necessary current to charge the battery. But if the voltage suddenly drops, the car simply won't start. In this case, you shoulduse the charger. This is exactly what most drivers do in situations like this.


This operation must be performed from a rectified current source. To do this, you can use any rectifier that allows you to adjust the voltage or charging current. If we talk about factory chargers, a quality device should provide charging up to 16 volts.

Today, there are two charging methods:

  • At constant current.
  • With constant voltage.

Experts say both methods are equivalent in terms of impact on vehicle battery life.

Charge at constant current

This operation is performed at a constant current. It is 0.1 of the nominal capacity of the battery for a 20-hour discharge. What current should be? If the battery is being charged by a charger, this parameter is easy to calculate. Divide the total capacity, measured in amp-hours, by 10. So a standard 60 Ah car battery should be charged at 6 amps.

What is the disadvantage of this method? If the battery is being charged at a constant current, this parameter must be periodically monitored. Thus, it is necessary to adjust the current strength every hour. Even with this method of charging, the battery begins to boil, and, as a result, there is a strong gas evolution at the end of the charge. This is not always good for the battery.

To avoid overcharging, you need to use a stepwise decrease in current strength asvoltage growth. Let's take an example. When our 60-amp battery reaches 14.4 volts, the current should be halved. That is, the regulator should be set to 3 amperes. With these parameters, charging the VAZ battery lasts until gas evolution begins (that is, the electrolyte begins to boil).

On some battery models there are no holes for adding water. In this case, experts recommend reducing the current to one and a half amperes at a voltage of 15 volts.

When can a battery be considered fully charged? This can be judged by the level of tension. Two hours after charging, this parameter should remain unchanged - in the region of 13.5-14.4 volts. For maintenance-free batteries, the figure is slightly higher - from 16 to 16.4 volts, depending on the purity of the electrolyte and the composition of the lattice alloys.

Charge at constant voltage

When using this method, the state of charge of the battery will depend on the amount of voltage that the charger provides. Here are some statistics. For a day of continuous charge at a voltage of 14.4 volts, the battery will be charged by 75 percent. If you increase the figure to 15 volts, the battery will be charged by 90. 100 percent can be obtained if the voltage level is 16.4 volts.

When you first connect, the current can reach 50 amps (and sometimes more). The exact figure depends on the internal resistance in the battery. In view of this, the memory is supplied with different circuits that allow you to limit this figure to 25 amperes.

As the battery charges, the voltage at the battery outlets will approachto what is in memory. At the end of the charge, the current strength approaches zero. When using this method, there is no need to constantly monitor the current strength and other parameters. The device automatically adjusts these values. It is according to this scheme that most of the memory now works.

At the end of the charge, the green light on the device will light up. And the voltage level at the terminals will be about 14.4 volts. This usually takes 10 to 12 hours. As for maintenance-free batteries, it takes about a day to reach a full charge.

Battery charge on the car itself

When the battery is used in a car, it is charged at a constant voltage. On most cars, the level is set to 14.1 volts (the maximum error is 0.2). This is much lower than the intense outgassing voltage. When the ambient temperature drops, the efficiency of such a charge decreases. Therefore, even with a working generator, the battery does not fully restore its capacity. Typically, the battery is only 75 percent charged. In this case, the voltage will be from 13.9 to 14.3 volts with the engine running.

battery charging
battery charging

Do I need to charge my car battery in winter? Experts say that in order to maintain normal capacity of the AKC, it is recommended to recharge it "in place" about once a month. This is especially true for those who use the car for short distances (up to ten kilometers). During this time, the capacity and voltage of the battery drops, and the regular generator does not have time to resume dataparameters.

Features of charging lead-acid batteries

These batteries also require periodic recharging. However, this type of battery has its own characteristics. So, there are no usual holes that allow you to measure the density of the electrolyte. The case is completely sealed, which is why charging with fast currents is unacceptable.

But what about in this case? To charge the car battery, you need to dismantle the battery. It is not recommended to perform these operations on site. It is necessary to install the battery on a hard and even surface in order to exclude the possibility of tipping over. The next step is to measure the residual voltage. This is done by the same memory. This way we will determine if the battery has a deep discharge.

If the voltage at the outputs is more than 11.5 volts, connect the device to the terminals and set the current at the start to 2 A. The charger should supply a voltage of 14.5 volts. A slightly discharged battery under such conditions will recover within three to four hours. At the end of the operation, the current on the device will decrease to 0.2 A. If so, then the car battery has been successfully charged.

Pay attention! It is forbidden to charge such lead-acid batteries with a current of more than 15 amperes. This can lead to irreversible consequences. Remember that overcharging is also very bad for the battery.

If deep discharge

If the voltage before charging was less than 11 volts, it will take much longer to recover the battery. Depending on the voltage, it is necessary to divert from20 to 30 hours to charge a car battery. The ABKB itself should be placed in a warm room with a temperature of at least +20 degrees Celsius. Note that deep discharge for lead-acid batteries is especially harmful. Repeated repetition of such a situation may damage the battery. How to restore it correctly? How much charge should the battery have? Experts say that the voltage at the charger should be 10 percent in Ah of the total battery capacity.

vaz battery
vaz battery

During the operation, you need to carefully monitor the process. Since lead-acid batteries have a completely sealed case, explosions are possible when gassing. To prevent this, with active drilling, you should immediately disconnect the charger from the power supply.

Can I charge such a battery on a car?

Experts do not recommend doing this. But in case of an emergency, you can charge the battery once. To do this, you must adhere to several conditions:

  • Power consumers must be completely turned off in the car. You should also remove the ignition key while charging.
  • The air temperature should be at least +20 degrees Celsius. This applies not only to lead-acid, but also to other batteries. In the cold, this process is not recommended.

Which memory should I use?

Today there are many brands and models of these devices. When buying, it is important to focus on the following criteria:

  • Sizes. The device must be compact.
  • Availability of different functions andmodes. It is desirable that the memory be as versatile as possible.
  • Presence of indication and manual adjustment.

Today Korean and German brands have proven themselves well. These are Hyundai HY-400 and Auto-Welle AW-05 1208. Feedback on these models is positive. Devices can work with both serviced and maintenance-free batteries.

What should I do if the battery is charging?

It happens that the red lamp on the dashboard lights up, indicating that the battery needs to be charged.

car battery charging
car battery charging

After starting the engine, this indicator should disappear. But if it continues to burn, then there is a problem with the car. The generator does not generate voltage, and such a battery cannot be driven for a long time (as the experience of motorists shows, no more than 100 kilometers). Why is the battery not charging? Not always the generator itself is the cause. You need to start small. If there is no battery charging voltage, the alternator fuses should be checked first. They are located in a common block or separately (as is the case with the Gazelle and Sable). If the fuses are blown, they should be replaced. The battery charging light should turn off. But if the fuses are intact, you will have to diagnose the generator itself. The diode bridge, brushes, voltage regulator or something else can be broken.


If the car battery runs out again after charging, it is not always the cause of leakage currents. In many cases, the problem lies in the densityelectrolyte. This is a special liquid, the state of which determines the voltage of the battery and the speed of discharge. When the level is low, the battery loses its capacity. And it's impossible to get it back. Thus, due to the low electrolyte level or its low density, the battery ages prematurely.

How to measure density?

There is a special device for this. This is a hydrometer. You can find one at any auto shop. It is inexpensive - about 200 rubles. The kit may also include a measuring tube with marks for monitoring the electrolyte level.

Note that measurements should be made at a temperature of +25 degrees Celsius. An important condition is that the battery must be fully charged. The liquid itself is inside, for which you need to open six covers on top (measurements are made in each). This can be done with a coin or a thick slotted screwdriver. What values should be on the hydrometer? The ideal density is 1.25-1.27 grams per cubic centimeter. As for the level, the lead plates must be completely covered with electrolyte. But with an excess, the liquid can go beyond the body. This causes current leakage. The ideal level can be changed using the dipstick.

charging the battery with a charger
charging the battery with a charger

We also note that sometimes car owners, when measuring electrolyte, are faced with a situation such as clouding or discoloration of the liquid. In this case, a complete replacement is required. The liquid should always be clear and clean throughout the life of the battery.

Another reason for rapid discharge may be poor-quality electrolyte, which was previously poured into the battery. In addition, the addition of running water in the case of high density leads to turbidity. In this situation, it is necessary to add only distilled water, otherwise the battery will be unstable.

How to top up? Charging features

Please note that in any operations with the electrolyte, you must not forget about protective measures. Since this is a very toxic liquid, you should only work with rubber gloves. Sleeves must be closed. And if the electrolyte comes into contact with the skin, immediately rinse the area with plenty of water.

We need to prepare containers for draining part of the old electrolyte, and also:

  • Measuring cup.
  • Funnel.
  • Pear enema.

So let's get to work. Using a pear, we pump out the old electrolyte from each can. We put it in a separate container. Next, pour new electrolyte through the funnel. Its volume should be 50 percent less than the pumped out liquid. An exception is the use of ready-made electrolyte mixtures. They are already diluted with distilled water at the factory so that the capacity is 1.28 grams per cubic centimeter.

car battery charging
car battery charging

You need to fill it strictly according to the level. The liquid should definitely cover the plates, but not too close to the openings of the cover. After that, the battery is charged by the charger. First you need to set a small current - 1 A. In this case, the plugs shouldbe unscrewed so that the gases freely leave the space. It is necessary to adhere to cyclic charging. After reaching the maximum allowable voltage, such a battery should be discharged, then charged again at low currents. This process is repeated until the density of the electrolyte reaches the required norm. After the nominal voltage of 14-15 volts is reached, the charge current is halved. If the electrolyte density does not change within two hours, the charging process can be stopped.

Helpful advice

After the electrolyte has been added to the battery, you need to tilt the case several times to one side and the other. This will eliminate air from the battery cans. But immediately after charging, you can not use the battery. It is necessary to wait about two hours for the previously boiling electrolyte to cool down.

Remember that at low temperatures, the self-discharge rate increases. Do not leave the battery in the cold for a long time without recharging. The density of the electrolyte may otherwise drop to 1.09 grams per cubic centimeter. In this case, the liquid will freeze already at -7 degrees Celsius.

Can the battery be restored in this way?

By topping up the electrolyte and properly charging the battery, you can restore the old battery. But it doesn't always work out. So, do not exclude such factors as the gradual shedding of the plates. If this process has begun, no amount of battery charging and electrolyte addition will help it. Even after a complete fluid change, the voltage will drop.

vaz battery charging
vaz battery charging

Sthe regular generator will not cope with charging. The battery will "sit down" both while driving and in the parking lot. Note that when the plates are shed, the new electrolyte can also become cloudy. In this case, the only way out is to replace the battery with a new one.

Tips for extending battery life

Specialists give several recommendations regarding the operation of a car battery:

  • You need to regularly check the voltage at the generator (when the engine is running).
  • Do not allow long-term storage of batteries, especially in cold weather. If the temperature is below -25, it is recommended to bring the battery into the house, even if the car is left overnight.
  • Check electrolyte density once a year and adjust or refill if necessary.
  • Deep discharge must not be allowed. This adversely affects the life of the battery. Periodically, you should fully charge the battery on a special charger, observing the desired current strength.

Also, experts advise keeping the battery case clean. Excessive dirt can cause unauthorized leakage of current, which leads to the discharge of the battery. Some more motorists intentionally do not remove the film from new batteries and drive like this for a long time. This cannot be done. The case must be free of films, as condensation may form in this layer. It also causes current leakage.


So we figured out how to properly charge the battery. This operation must be carried out at least twice a year. In winter, always move the battery to a warm At the same time, use high-quality chargers, preferably with the ability to automatically adjust the current strength. You should not give a large current in the hope that the battery will charge faster. This can only make the situation worse. Also periodically you need to control the level of electrolyte inside. It is this part that can cause undercharging or a decrease in battery capacity. But when restoring, you should adhere to the minimum current strength. Thus, periodic inspection and charging of the battery will help to increase the life of the battery.