How To Properly Charge Your Car Battery

Every driver should know how to properly charge your car battery. Compliance with the charging technology contributes to the safety and smooth operation of the electrical system and electrical appliances of the car, and also increases the battery life.

Each battery, depending on its type, capacity, voltage, and current output, may have different charging rules.

How To Properly Charge Your Car Battery

There are two ways to charge batteries: constant voltage and constant current. We will describe their features in more detail below.

DC Charging

This method consists in setting a constant current value on the charger. It should be 10% of the battery capacity.

For example, for a battery with a capacity of 70 Ah, the current during charging should be 7 A, for a 60 Ah battery – 6 A.

Unlike amperage, the voltage supplied to the battery during charging changes. The inconvenience of this method is that every 1-2 hours it is required to adjust the current strength, which requires constant presence near the device being charged.

The process should take place in a ventilated area since the electrolyte emits flammable gas during charging.

First of all, this applies to the old type of batteries being serviced. The more fully charged the battery, the more intense the gas formation.

At the beginning of charging, a low voltage is applied to the battery, and it gradually rises.

When it reaches 14.4 V, the current must be reduced by 2 times from the original indicator. For example, if the value was 7 A, you need to put 3.5 A. After the voltage reaches 15 V, the current is further reduced by half (from 3.5 A to 1.75 A).

Charging continues until the voltage value stops changing. If within 1-2 hours the voltage and current parameters stop changing, freezing in one position, then this means that the battery is fully charged and it does not make sense to do this longer.

Also, when fully charged, gas begins to flow intensively from the electrolyte (the number of bubbles rising to the surface of the liquid sharply increases).

Constant Voltage Charging

With this method, a constant voltage value is set on the charger, depending on the type of battery.

At the beginning of charging, the current strength has the highest value, and, moreover, the more the battery is discharged.

To prevent users from over-speeding up the charging time, most chargers have limiting circuits that do not allow setting the amperage above 20-25 A.

This is done so that the charger and the battery itself cannot fail when operating at the limit parameters.

In the process of charging the battery, the voltage gradually decreases, while the current drops almost to 0. The parameter changes exponentially.

The higher the voltage at the beginning of the process, the sooner the battery will be charged. If you set the value to 16.3-16.4 V, then the battery will be fully charged in about a day, at 16 V during the same time the charge will reach 95-97%, at 15 V – 85-90%, at 14.4 V 0 75-85%.

But too fast a process increases the release of gases, therefore, most modern batteries with a maintenance-free design have a limitation that does not allow them to be charged with a voltage of more than 14.4 V.

How To Charge The Car Battery

The car battery can only be charged from a DC source that can adjust the voltage and current supplied to the battery terminals.

Various types of chargers are now available in stores. There is also a variety of them called charging and starting devices.

Such devices allow you to start the engine by connecting in parallel to the battery. This can be useful, for example, in winter, in an unheated garage, when the capacity of the battery drops in severe frosts.

The device designed to charge the battery converts 220 V alternating current into direct current. The value of the output voltage must be at least 16-16.5 V. With lower parameters, many modern batteries cannot be fully charged.

The simplest type of battery is called “antimony” due to the fact that the lead from which the plates are made has antimony additives.

Also, the alloy may contain calcium, and sometimes a small amount of silver. The constant charging current level is set at 10% of the battery capacity (for a 70 Ah battery, the current is set at 7 A, respectively).

The constant voltage for such a battery should be 13.8-14.5 V. As the battery charges, the current characteristics decrease at an exponential curve.

Battery charging time depends on a number of factors:

  • degree of discharge;
  • capacity;
  • battery condition;
  • power of the device for charging.

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In theory, the more current is set during charging, the less time the battery will reach full charge.

But in reality, a high charging current increases the likelihood of discharge. To eliminate the risk of overcharging the battery, which reduces battery life, many car owners set a current of about 2 A.

The battery is left with the charger connected overnight (6-10 hours). With this approach, although the battery does not charge 100%, it retains its charge better in the future.

Please note that before connecting the battery to the charger, it is recommended to clean the contacts from traces of corrosion, plaque, and dirt. After charging, it is advisable to treat the battery terminals with special compounds to protect against oxides.

Important! In order for the battery to last a long time and not fail at the most crucial moment, it must be regularly serviced and monitored by the amount of charge, checking it once a month, or better more often. This should be done at any time of the year, but in winter it does not hurt to check the battery more often, because, in the cold, problems with it occur more often.

If charging is carried out on a serviced battery, then before starting it, it is imperative to unscrew the plugs on all banks. You also need to remove the plug.

This is necessary so that the gases formed during the process do not increase the pressure inside the case above the critical one and do not damage the structure.

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After removing the plugs, it is necessary to check the level at which the electrolyte is in the cans. It must completely cover the plates.

If the level is less than required, then distilled water must be added to the jars. It is also not worth pouring over the required value.

It is not worth charging serviced batteries on residential premises. This is due to the fact that when charging, the electrolyte in them intensively releases flammable and is harmful to people.

Therefore, charge in a ventilated garage or other ventilated area where people are not constantly.

Maintenance-free batteries do not have such a limitation due to the fact that they practically do not emit gas. They can be charged even in an ordinary apartment.

When To Charge The Battery

If the vehicle’s alternator can handle charging, then the battery does not need to be charged using an additional device.

Therefore, we advise you to check the charge level first.

There are several ways to do this:

Checking The Voltage.

 This method is the easiest and fastest. To carry out a measurement, it is enough to have a simple multimeter in the instruments.

The cost of such a tool starts from 300-to 500 rubles. Set the switch of the tester to the position for measuring DC voltage up to (or near) 20 V. Then you need to put the red probe on the positive terminal of the battery, and the black one on the negative one.

The nominal voltage for a car battery is 12 V. In reality, it is more important.

For a working and new battery, when fully charged, it should show about 12.7 V. When discharged by half, this value drops to 12.2 V.

This means that it needs additional recharging. If the screen displays a value of 11.6-11.7 V, then the battery has practically exhausted its capacity, you cannot go on the road with it, first, the battery must be charged.

How To Properly Charge Your Car Battery | Rean TimesChecking the voltage on the car battery.

Checking The Density of The Electrolyte

The method is suitable exclusively for serviced batteries, in which the plugs can be removed from the cans.

A hydrometer is required. It is necessary to lower the end of the device into the battery jar, and draw liquid into the device so that the float floats.

By combining the risks on the case with the scale, the density of the electrolyte is judged. For a charged battery, it should be at 1.27 g / cc. cm.

If the indicator is less, this means that the battery is discharged and needs to be recharged. In maintenance-free batteries, there is a round window on the top cover, by the color of which you can visually determine the state of charge of the battery.

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Battery charge indicator.

Difficulty Starting The Car Engine

Most often, problems with the operation of the starter arise due to insufficient battery charge.

If the lights on the dashboard begin to dim when the starter is turned on, then the battery is almost certainly dead.

Attention! It is not recommended to allow a significant battery discharge. When in a discharged state, the process of sulfation of the working plates occurs, which leads to a decrease in the capacity of the battery and a decrease in its resource.

Is it Possible To Charge The Battery on The Car?

Novice drivers are usually interested in whether it is necessary to remove it from the car when charging the battery using a charger.

It is not necessary to remove the battery from the seat, but you need to disconnect the terminals. At a minimum, you need to remove the negative contact, or better both.

The fact is that when charging with unremoved terminals, 2 unfavorable moments arise:

  1. Electric current with increased parameters circulates in the electrical system of the car, acting on electrical appliances;
  2. Leakage currents will increase the charging time.

In addition, there is the possibility of a power surge that could damage an important electrical appliance.

This is especially dangerous on modern, expensive cars equipped with electronic ignition control systems, computers, and climate control systems. Due to the fact that the terminals were not removed, you can get into an expensive repair.

How To Charge a Calcium Battery

Calcium batteries, designated by the letters Ca-Ca, are mostly maintenance-free.

They quickly gained popularity due to a number of positive qualities, including:

  • high capacity;
  • significant starting current;
  • almost complete absence of electrolyte evaporation.

However, these batteries have their drawbacks as well. Their main unpleasant feature is their sensitivity to discharge.

It is enough to allow a deep discharge 3-4 times for the capacity to decrease several times. Therefore, discharge control and regular charging are critical for this type of battery.

Calcium batteries need to follow the charging technology, which has its own characteristics. You need to purchase a charger that is capable of generating a voltage of 16.1-16.5 V.

If the charger has a lower output voltage, then the battery will constantly undercharge. So, at a current of 14.8 V, the battery will gain 45-50% of its capacity, at 15.5 V – 70-80%.

At low voltage, a calcium battery can never gain 100% of its capacity. Therefore, you need to buy only modern type chargers.

For example, the Orion-Vympel-55, equipped with a programmable charging cycle, is a suitable model, which allows the battery to be charged under minimal supervision.

The problem is that the generators on cars give off a voltage of only 15 V. This means that they cannot fully charge the calcium-type battery.

Because of this feature, this type of battery needs regular periodic recharging once a month. It is especially important to do this in winter when the capacity of the battery decreases due to frost.

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Calcium Battery

As described above, you need to buy a charger equipped with a programmable cycle.

The charging process looks like this:

  1. A voltage of 16.1 V is set on the charger panel. The current indicator should be standard 10% of the battery capacity, i.e. for a 70 Ah battery, set the current to 7 A).
  2. The battery is charged with the set parameters until the current strength drops to 0.5 A. The duration of this period depends on the degree of discharge, capacity and condition of the battery.
  3. Now 2 modes are set on the dashboard: upper and lower. Values ​​for the first: 16.1 V and 3 A, for the second – 13.2 V and 0 A.
  4. The charging device arranges a “swing” that allows you to bring the capacity to 100%. A current of 3 A is supplied to the battery, while the voltage gradually increases to 16.1 V. As soon as it reaches this value, the current becomes equal to 0. The voltage gradually decreases to 13.2 V. Then the cycle repeats again.

The more the battery is charged, the less the oscillations of the “swing” become in time, at first it rises for tens of minutes and decreases rapidly.

Gradually, the nature of the work changes to the opposite: a quick increase in less than 1 minute and a slow decrease in a few minutes. This indicates that the battery is fully charged.

How to Charge a Gel Battery

Gel batteries are labeled GEL. They have several advantages over traditional batteries.

Most often they are used as traction batteries for electric vehicles, for cars with powerful media systems, SUVs, ATVs, and motorcycles.

They are also widely used to ensure the smooth operation of household appliances, computers, volatile gas heating systems, etc.

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Gel Battery

Pros of Gel Batteries:

  1. They are shock-proof and can be tilted without the risk of electrolyte spillage.
  2. The current output remains high even with a charge of only 20-30%.
  3. Withstand up to 1 thousand recharge cycles, and often much more than this value, depending on the specific model and compliance with operational rules.
  4. The self-discharge current is very small, thanks to which a charged battery can maintain voltage for a long time. For a year, the battery loses only 20% of its charge.
  5. It is possible to store for a long time completely discharged in a room without heating, even in winter.

Cons of Gel Batteries:

  1. They are much more expensive compared to their conventional counterparts.
  2. Do not overcharge, in this case, the capacity of the battery and its resources drop sharply.

The charging algorithm of a gel battery is slightly different compared to a traditional battery:

  • A conventional charger with adjustable output voltage and current is sufficient.
  • The amperage should be a standard 10% of the capacitance rating. It is allowed to increase the charging current up to 30% of the capacity (for a battery with 70 Ah this will be 21 A). But you only need to do this if the battery needs to be changed urgently. It is not worth doing this constantly due to a decrease in the service life.
  • Due to the fact that gel batteries are sensitive to high voltages, this indicator should not be set higher than recommended for this model. Usually, it is 14.5-15 V. Recommended parameters are always indicated on the marking applied to the battery case.
  • The sticker also indicates the maximum charging current (also referred to as the max initial current). This value must also not be exceeded.
  • The charging period depends on the magnitude of the charging current. It is determined by dividing the capacity by the set charging current. This means that if charging is carried out at 10% of the nominal, then it will take 10 hours, if 30%, then, accordingly, a little more than 3 hours. For fear of overcharging the battery, it is better not to use old types of chargers, but to use new devices with an electronic unit that automatically monitors the voltage and current output.

Gel battery charging parameters.

Attention! The danger for gel batteries of increased voltage comes from the fact that because of it, the gel containing the electrolyte begins to break down. Under the influence of the current, it begins to melt. The longer the exposure to high voltage, the worse for the battery.

When charging a serviced gel battery, it is imperative to remove the plugs so that pressure does not build up inside the case.

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The charger is connected to the appropriate terminals, then the required voltage and current are set on the device.

During charging, the voltage will rise, so you need to make sure that it does not go beyond the maximum limits (often referred to as cycle use).

If the voltage has exceeded it, it is necessary to reduce the strength of the charging current in order to reduce the supplied voltage as well. Usually, 10-12 hours should be enough for a full charge.

The Standby Use value is often indicated on the battery, which indicates what voltage should be on the battery in storage mode.

If storage is long, then manufacturers recommend recharging from time to time at a low voltage (usually within 13.5-13.8 V) to maintain performance. This current may be labeled “buffered” or “buffered” on the label.

If the voltage indicators are not observed, the battery will quickly fail.

It is best to buy a modern electronic charger for a gel battery with automatic monitoring of voltage and current indicators, which will not allow you to recharge the battery on its own.

Also, such chargers can set the charging mode themselves, depending on the degree of rarefaction of the battery and the ambient temperature. There are also charger models specifically designed for gel batteries. It is advisable to purchase just such.

Attention! If you have a gel model of the battery on your car, check from time to time the voltage that the relay regulator on the generator gives out. At a high voltage current, the battery will become inoperative very quickly, up to several hours. For insurance, you can install battery terminals with a built-in relay regulator, which will limit the voltage when it is exceeded above a predetermined one.

How To Charge The Hybrid Battery

The peculiarity of hybrid batteries is that they use plates with different additions of alloying elements.

Some of the plates are antimony, others are calcium. Such batteries are low-maintenance, but the banks on them are equipped with plugs.

Therefore, it is necessary to check their electrolyte level in them. This is done every 2-3 months. If the level drops below the set level, distilled water is topped up.

The main advantages of hybrid batteries are that they tolerate deep discharge well, delivering significant inrush current. They also stand out for their low cost, which is about 2 times lower compared to calcium batteries.

Charging the battery of a standard type does not differ from the work with traditional batteries. The current indicator is set at 10% of the battery capacity indicator.

But it can be increased to 30% if you need to cycle in a short time. The best performance is achieved with a current rate of 3% of the capacity.

For a capacity of 60 Ah, this is 2 A. The voltage should be 13.8-14.2 V. Charging is stopped when the voltage rises to 14.2 V, and the current decreases to 0.3-0.5 A.

Attention! It is better not to set high amperage readings, as this leads to the boiling of the electrolyte. The danger of this process is not only in the release of harmful gases but also in the fact that the plates are heated, from which the active mass begins to crumble.

In hybrid batteries, it is necessary to regularly monitor the level of electrolytes during the summer period.

The fact is that the battery produces a higher voltage than traditional batteries. This feature improves the start of the engine, but in summer it leads to the battery warming up, which is why the electrolyte heats up and boils when the engine is turned on.

When water evaporates, the concentration of the electrolyte increases, its level drops, and the plates end up in the air, starting to collapse.

How To Charge an AGM Battery

Often, AGM technology is confused with gel technology. In fact, these types of batteries are significantly different.

AGM batteries are capable of delivering a high starting current, reaching values ​​of 500-900 A. This allows you to start any car, even with a diesel engine, in almost any frost.

Also, such batteries are charged much faster (almost 3 times). An important advantage of AGM batteries is their extended service life (3-5 years longer than a traditional lead-acid battery).

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AGM Battery For The Car

There are 3 options for charging AGM batteries:

1. Charging, accumulation, and storage. The charger can be recharged with a battery in a car or using a charger. The voltage is in the corridor 14.2-14.8 V, but should not exceed 15.2 V (you need to clarify this point in the instructions for the battery).

The charging current is within 10-30% of the capacity. The energy storage process is carried out after a deep discharge. In this case, the voltage should be as described above, and the current strength should be 10% of the capacity. In the case of storage, the voltage does not change, and the current strength is 5-10%.

2. Charging and storage. This option is most often indicated by manufacturers. For charging, parameters of 14.2-14.8 V are used with a current strength of 10-30% of the battery capacity. In the case of storage, the voltage is 13.2-13.8 V at the above amperage.

3. Charging. Some manufacturers do not report the storage conditions at all, but only indicate the parameters for charging. They are the same as in the paragraph above – 14.2-14.8 V at a current strength of 10-30% of the battery capacity.

It is also important for AGM batteries to maintain the recommended voltage and charging current.

It is best to use a charger with an electronic unit that has 2 modes. The presence of such a charger makes it possible to charge the battery without constant monitoring and guarantees that the current parameters will be in a given corridor.

In the case of using an old charger, you will need to constantly monitor all parameters manually

How To Charge a Maintenance-Free Battery

Many modern battery models are maintenance-free. They do not have access to the jars, so it will not be possible to check the electrolyte level and top up the distillate in them.

Such batteries are charged in the same way as conventional ones, in 2 ways: with constant voltage or constant amperage. It is best not to risk it, but to buy a modern charger with an electronic unit and an indicator of the end of charging. Usually, at the end of the cycle, a colored indicator on such a device lights up.

The old, mechanical-type charger will have to be controlled by yourself. You will need to determine the degree of battery discharge.

It can be determined by the voltage at the battery terminals. 12.7V means it is fully charged. 11.7V full discharge, 12.2V 50% discharge.

The charging current must be 10% of the battery capacity. For example, with a half discharge and a battery capacity of 60 Ah, 30 Ah will be required to restore capacity. 10% of 60 Ah – 6 A. Divide 30 Ah by 6 A, and you get 5 hours. Therefore, the charging time is 5 hours.

You cannot exceed the charging current threshold of 10%. Such an experiment is guaranteed to lead to battery failure or at least a decrease in its capacity and operating period.

Overcharging has a fatal effect on any type of battery. If the charging cycle takes 5 hours, then keeping the battery with the charger connected for 8 or 10 hours is not only meaningless but also harmful.

The amount of charge, in this case, will not increase, but the electrolyte will boil, which will lead to the evaporation of water from it and the heating of the plates.

This process is especially dangerous for an unattended structure. If distilled water can be added to an accumulator equipped with plugs, then in an unattended battery this possibility is absent at the root.

The battery is equipped with a special valve that relieves pressure when the pressure inside the case exceeds a critical value.

This protects the battery from destruction, but the loss of fluid is irretrievably compensated. Lowering its level below the required level will damage the plates and reduce the service life of the device.

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