What does forward and reverse battery polarity mean?

Direct and reverse polarity of the battery - what it means and what is the difference

For a car, the battery is the most important element. It ensures a confident start of the internal combustion engine, powers electronic components and pre-installed devices. To ensure this process, the battery must be connected to the on-board network using pole terminals. The latter are located on the lid of the sealed housing. One of the terminals is marked “-”, and the other “+”. The battery is also charged using the terminals. The main thing when connecting and recharging is not to mix up the polarity terminals, and this requires knowledge of the polarity of the batteries. Let's find out what battery polarity is, how to determine it, and what it is.

What is polarity?

Polarity is a concept that defines the location of the pole terminals (external current-carrying elements) on the cover or front side of the battery. There are two standard position types:

But the current leads can be located differently. Such “exotic” batteries have not caught on with car owners in Europe and the CIS countries, so they are extremely rare on store shelves. It remains to find out what the polarity of the battery is, direct or reverse, and whether there is a difference between the batteries.

Straight battery polarity

Batteries of this type were developed by Soviet engineers. All cars produced in the USSR were equipped with direct-type batteries. They are characterized by the following arrangement of pole terminals - “+” on the left and “-” on the right. Batteries are still produced with this arrangement of current leads today. A fairly impressive percentage of vehicles of foreign brands that are assembled in the CIS countries are equipped with a battery with a left “+”.

Reverse battery polarity

Reverse polarity batteries are manufactured by manufacturers in European countries. Therefore, all imported vehicles are equipped with batteries in which the current terminals are located exactly the opposite - “+” on the right and “-” on the left.

How are batteries different?

How to identify forward and reverse polarity?

Determining the polarity of a product is not difficult. You need to turn the battery so that the front side is facing you. The front side is:

• where the label with characteristics is pasted;
• in which the location of the pole terminals will be closest to the viewer;
• where identification marks and markings are applied.

In most cases, the pole terminals are labeled “+” and “-” directly on the body. If, when you turn the battery towards you, the positive terminal is located on the left, then it is a battery with straight polarity. If there is a “-” on the left, it means the opposite. The marks are generally accepted designations, but they may not be on the body. Equipment manufacturers often use their own markings. For example, pole terminals are distinguished by color. Positive is marked with a red cap, negative with black or blue.

There are also other designations:

• reverse polarity - “0” or “R”;
• straight polarity - “1” or “L”.

Having figured out what the difference is between direct and reverse battery polarity, it will not be difficult to remember the generally accepted symbols. They are valid for batteries produced for passenger cars. When determining the type of battery for buses, trucks and any other heavy equipment that uses batteries with a capacity of 110 Ah or more, the designations will be different:

• the left “+” indicates equipment for European special equipment - reverse polarity;
• the right “+” indicates equipment for Russian special equipment - straight polarity.

Also, when purchasing a battery, you need to take into account differences in the production of cases. Asian battery manufacturers place the pole terminals so that they protrude well above the surface of the top cover. Most European companies make the case more ergonomic, that is, they recess the terminals. Asian devices have significantly smaller terminal diameters than European ones. For comparison, Asia/Europe - “+” output 12.7 mm/19.5mm and “-” output 11.1 mm/17.9 mm.

Is it possible to set a different polarity?

Theoretically it is possible. But, as stated above, this can lead to unnecessary waste of money and additional hassle with placement in the socket, the length of the wires, and mismatched terminal diameters. It's another matter if you connect the new battery incorrectly. This can lead to serious consequences. Therefore, if the technical documentation indicates that the car requires straight polarity of the battery, it is wiser to buy a battery with straight polarity.

What will be the consequences if the polarity is reversed when connecting?

• generator breakdown;
• overheating of the diode bridge;
• failure of diodes (accompanied by a pop when the case is destroyed, a smell);
• failure of on-board electronics;

Important! Most electronic devices have reverse polarity protection.

But not powerful consumers of electric current - amplifiers, radio tape recorders. They contain elements, such as capacitors, that are extremely sensitive to polarity reversal. Their failure is guaranteed due to heating. Initially, as the temperature rises, the capacitor will swell and then explode. The process will be accompanied by a characteristic sound and smell.

• failure of the relay in the wiring;
• short circuits in the network, etc.

When lighting a cigarette, the reverse and direct polarity of the battery is also extremely important, as described above. Incorrect connection of the battery terminals will cause just as many problems for the donor. First of all, it will cause an instantaneous short circuit with a voltage of 24 V. In the best case (if the terminal wires have a sufficient cross-section - at least 16 mm2), the connecting wires will heat up and melt, in the worst case, the driver will get a burn on his hands. An increase in temperature can only mean one thing - incorrect placement of the clamps.

Therefore, lighting is performed according to the following scheme:

• The crocodile terminal is attached to the positive terminal of the car being lit;
• The crocodile terminal is attached to the positive terminal of the donor battery;
• The crocodile terminal is attached to the negative terminal of the donor battery;
• The crocodile terminal is installed on the negative terminal of the car being lit.

Important! When installing the clamps, pay attention to the color marking of the wires. Connect “+” with “+”, and “-” with “-”, or red with red, and blue (black, green) with blue.

Changing battery polarity

Algorithm for reversing battery polarity:

• discharge the battery to “0” - attach some load to the terminal;
• reconnect the negative wire to the positive terminal, and the positive wire to the negative terminal;
• charge the battery;

Important! If everything is done correctly, the device will begin to actively take charge. In the process, the temperature will increase, and significantly. This is normal and indicates the beginning of the conversion of "+" to "-", "-" to "+". The plates inside the cans also change.

• turn off the unit when the cans boil.

This procedure is fraught with consequences. Especially if the battery is not of high quality. Cheap devices use very thin lead and dioxide plates. Their thickness is slightly larger than foil. They will not withstand sulfation and will collapse. You should not carry out a polarity reversal without checking the characteristics of the battery if it has already been used. You need to check whether the electrolyte inside the compartments is cloudy, whether there are any closed cans, and whether the device has sufficient density. If there are any problems with the battery, then it will not withstand the procedure. Therefore, in order not to waste money and not expose yourself to car danger, it is wiser to understand the concept of battery polarity and buy those recommended by the car manufacturer.

Rechargeable batteries

Information site about energy storage devices

Battery polarity

Polarity - the location of the connecting terminals on the battery cover, which are current-carrying elements. Since there are only two poles - positive and negative, there are few options for their location - forward and reverse. We will consider in relation to what it is customary to determine the location of the terminals, what will happen if the poles are accidentally mixed up when a polarity reversal is deliberately done.

What does forward and reverse battery polarity mean?

The terminals on the battery are always located in a certain sequence, according to the standard of the countries of origin. There are only two terminals, plus and minus. They may have different positions, but it turned out to be most convenient for maintenance to place the terminals on the cover. Moreover, they can be raised or recessed, distinguishing the European and Asian types.

The terminals are conveniently located on the cover on both sides. Direct and reverse polarity distinguish batteries only by changing the location of the poles. If straight, they consider the position when you read the inscriptions on the front side, and your right hand touches the right plus button. Reverse position - the same hand touches the negative button.

This is important to consider when buying a battery to replace an old one. Connecting the terminals the other way around will be inconvenient; you will have to extend one wire and shorten the other.

How to determine whether the battery polarity is direct or reverse

Each battery has a front side with marketing and informational stickers. If you place the battery facing you, the terminals are located on the right and left.

“Straight” polarity is sometimes marked with the number 1. This is a Russian battery layout. If the battery is facing forward, the plus button is under the left hand, red or with a grooved plus. Right - negative

“Reverse” polarity in classifications is marked with the number “0”. To decide, you need to place the battery facing you. The left hand will rest on the negative terminal, and the right hand on the positive terminal.

Direct and reverse polarity indicate the difference in the internal circuit of the cans' contacts on one side or the other. In practice, this means that when replacing a battery, the owner can mix up the poles when connecting to the car tires.

Difference between forward and reverse battery polarity

The direct and reverse circuits for connecting cans into a battery do not differ in anything other than the location of the poles. But if you install the wrong battery in the slot, problems may arise. There will be even more of them if the wires do not fit or the polarity is reversed.

Polarity of cargo batteries

Of course, it is better to install the battery with the correct polarity, but there is more space under the hood and the wires are longer, so any battery can be connected correctly. It is important not to mix up the poles when assembling the circuit. Due to the fact that batteries for trucks are larger, they have more connection options - the poles are located vertically, horizontally and diagonally, interchanging places.

How to determine battery polarity

Trucks are equipped with capacious and heavy batteries. They define direct and reverse polarity in exactly the same way. On the right, the positive pole is direct polarity, the negative pole is reverse polarity. You just need to look not from the face, but from the side, where the conclusions are closer. And reverse polarity in a truck is marked with the number “3”, and direct polarity with the number “4”. If the contacts are located diagonally, they are marked with the number “2”. There are also types of pole locations marked “9” and “6”

What does reverse battery polarity mean?

Reverse polarity means there is variability in the fit - the relative arrangement of battery poles, even from the same manufacturer, can be forward and reverse. This allows for more efficient use of the engine compartment space, creating a convenient layout. It is all the more important to choose exactly the same battery. If the polarity is reversed, whether in a truck or a car, the cathode will always be under the right hand, provided the battery is positioned correctly.

Changing battery polarity

Reversing battery polarity can happen accidentally or intentionally. If you mix up the terminals when lighting a cigarette, there are material costs for both the donor and the acceptor.

If you accidentally changed the polarity in your car, then at best the main fuse will burn out, at worst - the diode bridge. The faster you notice the jamb, the less the loss.

Changing the polarity, like reversing the polarity, is used to restore the functionality of a sulfated battery. The battery eats lead sulfate with appetite, cleaning the plates. But polarity reversal means the battery operates contrary to the rules. The forced measure must be temporary. It is much better to use a double polarity change when desulfating.

Polarity is direct, reverse - everything seems to be clear. But excesses happen. We offer a video on the topic.

What is direct and reverse battery polarity?

Each battery has pole terminals on its body - minus (-) and plus (+). Through the terminals it is connected to the vehicle’s on-board network, powering the starter and other consumers. The location of the plus and minus determines the polarity of the battery. It is important for drivers to know exactly the polarity of the battery so as not to mix up the contacts during installation.

Battery polarity

Polarity refers to the arrangement of current-carrying elements on the top cover or front side of the battery. In other words, this is the position of the plus and minus. The current leads are also made of lead, as are the plates inside.

Direct and reverse polarity

There are two common layouts:

• straight polarity;
• reverse polarity.

During the Soviet period, all domestically produced batteries were with straight polarity. The pole terminals are arranged according to the diagram - plus (+) on the left and minus (-) on the right. Batteries with the same circuit are still produced in Russia and the post-Soviet space. Foreign-made batteries that are made in Russia also have this terminal arrangement.

On such batteries, the minus is located on the left and the plus on the right. This arrangement is typical for European-made batteries and therefore this polarity is often called “Europolarity”.

Accumulator battery

The different position schemes do not provide any special advantages. It does not affect the design and operational features. Problems may arise when installing a new battery. A different polarity will force the battery to change position and the wire may not be long enough. Also, the driver can simply mix up the contacts, which will lead to a short circuit. Therefore, it is important to decide on the type of battery for your car when purchasing.

How to determine?

It's not that hard to find out. First you need to turn the battery with the front side facing you. It is located on the side where the stickers with characteristics and logo are located. Also, the pole terminals are located closer to the front side.

On many batteries you can immediately see the “+” and “−” signs, which accurately indicate the polarity of the contacts. Other manufacturers indicate information in the markings or highlight the current leads in color. Usually the plus is red and the minus is blue or black.

In the marking, reverse polarity is indicated by the letter “R” or “0”, and direct polarity by the letter “L” or “1”.

Differences in the body

All batteries can be divided into:

They have their own standards for production and pin placement. European batteries are usually more ergonomic and compact. The output contacts have a larger diameter. Plus – 19.5 mm, minus – 17.9 mm. The diameter of the contacts on Asian batteries is much smaller. Plus – 12.7 mm, minus – 11.1 mm. This also needs to be taken into account. The difference in diameter also indicates the type of polarity.

Is it possible to install a battery of a different polarity?

This question often arises among those who inadvertently bought a battery of a different type. Theoretically, this is possible, but it will require costs and unnecessary red tape with installation. The fact is that if you buy a battery with reverse polarity for a domestic car, then the length of the wires may simply not be enough. You can't just lengthen the wire. It is necessary to take into account the cross-section and diameter of the terminals. This may also affect the quality of current transmission from the battery.

The best option would be to replace the battery with another one with a suitable contact arrangement. You can try to sell the purchased battery so as not to be at a loss.

Changing battery polarity

Some drivers resort to the method of reversing the battery polarity. This procedure is to swap plus and minus. It is also done to restore battery performance. Reversing the polarity is recommended only in extreme cases.

Attention! We do not recommend carrying out this procedure independently (without the help of professionals) and in conditions that are not specially equipped. The sequence of actions below is given as an example, not an instruction, and for the purpose of complete disclosure of the topic of the article.

1. Discharge the battery to zero by connecting some load.
2. Connect the positive wire to the negative, and the negative wire to the positive.
3. Start charging the battery.
4. Stop charging when the cans boil.

During the process, the temperature will begin to rise. This is a normal phenomenon and indicates a reversal of the poles.

This procedure can only be carried out on a working battery that can withstand active sulfation. In cheap batteries, the lead plates are very thin, so they can simply collapse and not be restored. Also, before starting to change the poles, you need to check the density of the electrolyte and the jars for short circuits.

What can happen if you mix it up during installation?

If the polarity is reversed, the following can happen:

• blown fuses, relays and wires;
• failure of the generator diode bridge;
• burnout of the electronic engine control unit, alarm system.

The simplest and cheapest problem can be a blown fuse. However, this is their main function. You can find a blown fuse with a multimeter by “ringing”.

If you mix up the contacts, then the generator, on the contrary, consumes energy from the battery rather than providing it. The generator winding is not designed for incoming voltage. The battery may also be damaged and fail. The simplest option would be to burn out the desired fuse or relay.

A big problem can be the failure of the electronic engine control unit (ECU). This device requires correct polarity despite its built-in protection. If the fuse or relay does not blow out in time, then the ECU will most likely fail. This means that the car owner is guaranteed to face expensive diagnostics and repairs.

Most devices in a car's electrical system, such as a car radio or amplifier, are protected against polarity reversal. Their microcircuits contain special protective elements.

When “lighting” from another battery, it is also important to observe the polarity and sequence of terminal connections. Incorrect connection will cause a short circuit at 24 volts. If the wires have a sufficient cross-section, they may melt or the driver himself may be burned.

When purchasing a new battery, carefully read the labeling and ask the seller for all the characteristics of the battery. If it so happens that you purchased a battery with the wrong polarity, then it is best to replace it or purchase a new one. Extension of wires and changing the position of the battery should only be done as a last resort. It is better to use a suitable device than to spend money on expensive repairs later.

Direct and reverse battery polarity: what is the difference and how to determine.

Direct and reverse battery polarity: what is the difference and how to determine

The main function of a car battery is to start the engine. Under normal conditions, the wasted energy is replenished by the generator immediately after the engine is started. Thus, automatic recharging occurs without requiring external intervention. If there is not enough charge to start the engine, charge from an external power source. At the same time, it is taken into account that there is reverse and direct polarity of the battery, which determines the connection diagram of the terminals.

For recharging, use chargers or the battery of another car. If possible, remove the battery by disconnecting the ground and power terminals. The case is cleaned of contaminants and, using a visual inspection, the electrolyte level is assessed and the polarity of the battery is determined. You can check the electrolyte level only in non-sealed batteries, the casing of which has special holes with covers. If electrolyte leaks through cracks, the battery is considered unusable and will need to be replaced.

What is battery polarity and how is it determined?
On the body of the car battery there are two current-carrying elements to which the terminals of the charger or the car's electrical circuit are connected. The markings of the contacts “+” and “-” indicate the polarity of the battery. It is also present on the terminals of chargers, which is a hint for correct connection.

And charging a battery with reverse polarity differs only in the location of the current-output contacts on the housing. To avoid mistakes, place the battery facing you. The front part can be identified by the presence of information inscriptions and stickers. If “+” is located on the left and “-” on the right, the polarity is straight. If the signs are reversed, you have reverse polarity of the car battery. Each battery model has a specific marking, the last letter or number of which indicates the polarity of the battery (straight or reverse). How to determine in practice: The reverse is marked with the number “0”, the letter “R” or the abbreviation “op.” The straight line is indicated by the number “1”, the letter “L” or “p.p.”

Practical differences between direct and reverse battery polarity

To understand how important it is to determine the polarity of a car battery, you need to be aware of the consequences. So, when starting the engine from another car (lighting up), an incorrect connection provokes a short circuit, which after a few minutes goes into the fire phase. Therefore, when sparking occurs, the wires are urgently disconnected. In a situation where a motorist reverses the polarity when charging the battery with a charger, the charger (if it is of poor quality) may burn out. A reversal may occur in the battery - a change in polarity. The positive contact will become negative, and the negative contact will become positive.

Fixing this problem is simple:

— Completely discharge the battery.

- Charge it with the correct polarity.

Battery charging technology

After it has been established what polarity the battery has, proceed to selecting the charging mode. It is installed on the charger. There are three of them:

1. Constant voltage method (14.6-15 V) - used for sealed batteries, the design of which does not allow checking or changing the electrolyte level. In this mode, the voltage is kept constant, and the current decreases, reacting to the increasing internal resistance of the battery.

2. DC charging is the most common method. The maximum battery charging current is 10% of its capacity (with a capacity of 50 Ah, the current should be 5 A). In this mode, charging is performed to a voltage of 14.4 V. Further, until full charging, the current is halved (5% of the battery capacity). If the charger does not allow you to accurately set the desired mode, the closest one to the smaller side is selected. In this case, the full recovery time will increase, but it will be more gentle than fast charging with high currents.

3. Combined method - used in automatic chargers that do not require human intervention. The method consists of two stages: first, the energy is replenished with a constant voltage, and then with a constant current.

For batteries with direct and reverse polarity, there is no difference in the choice of charging mode. The only thing that matters is the correct connection: first the plus is connected to the plus, then the minus to the minus. After this, the charger is turned on. Turn off in reverse order. To charge the battery from another car, you need to connect the pluses of the batteries (red wire) and then the minuses (black wire) using wires with alligator clips. Even if one car has reverse polarity and another has direct battery polarity, remember that this is only a design difference in the arrangement of the contacts. After connecting, the engine of the charging vehicle is started for up to ten minutes and then turned off. Next, check the battery being charged and repeat the process if necessary.

Why the battery is not charging and what can be done

The average battery life is about six years. Gradually, the discharge rate increases and the charging efficiency decreases. The reason for this is sulfation of the plates or accumulation of sulfate deposits on the plates. It is formed during a chemical reaction between sulfuric acid (electrolyte), lead and lead dioxide (the materials from which the plates are made). Theoretically, when charging the battery, this process should be completely reversible, but in practice the sulfate does not return completely to its original state. This problem can be eliminated by desulfating the battery by changing the polarity or reversing the polarity.

To do this, the battery is completely discharged, and then charged by connecting the minus to the plus, and the plus to the minus. As a result, the arrangement of charges on the contacts changes, which means the reverse polarity of the battery will become direct.

Reversing the polarity allows you to restore up to 70% of the battery capacity.

However, this may be inconvenient, since in the absence of the owner of the car, it will not be clear how to find out the polarity of the reconditioned battery. To solve this problem, if the battery is initially of good quality (a low-quality one will simply burn out), you can immediately perform a reverse polarity reversal, restoring up to 80% of the capacity.

Car battery polarity: what is it?

An important element of a car's power supply is the battery. A charged and correctly installed device starts the engine and helps you get started. But Russian and foreign car models use batteries with different polarities. And if the terminals are mixed up when charging, “lighting” or connecting, the consequences for the battery or car can be very disastrous.

What is polarity in a battery and what is it like?

In batteries, polarity refers to the location of the conductive elements on the equipment cover. The car's electrical circuit or charger is connected to these contacts. Depending on the location of the positive and negative terminals, the polarity of the device is determined.

Batteries with straight polarity were installed on all Soviet cars.

If you look at the battery from the side of the current terminals, then with straight polarity there should be a positive contact on the left, and a negative contact on the right. If reversed, the terminals will be located in reverse.

In batteries for trucks, the terminal arrangement is different. Unlike batteries for cars, here the contacts are located not on the front, but on the left. If the battery has a direct circuit, then the contact closest to you will be positive, if it is reversed, then it will be negative.

View of the front side of a truck battery.

How to determine battery polarity

If you place an order in an online store and do not see the battery itself, you can find out the connection diagram by looking at the labeling of the selected battery. The letter “R”, the number “0” or the abbreviation “op.” models with reverse polarity are indicated, devices with direct polarity are marked “L”, “1” or “p.p.” In the description of the equipment, the concepts of “Russian” (“Asian”) and “European” polarity are also found: the first is direct, the second is reverse.

The terminals themselves, in addition to the “+” and “-” signs, are marked with the abbreviations “POS” and “P” (for positive contacts) or “NEG” and “N” (for negative conductive elements). Also, on some models, the contacts may differ in thickness: the diameter of the positive ones is usually larger.

Unfortunately, the markings on the product do not always correspond to reality, and sometimes they are completely absent, the description contains false information, and the sellers do not understand the issue of polarity. In order not to waste money, and especially not to damage the car’s mechanisms, carefully and responsibly approach the choice of battery and do not buy from dubious sellers.

Remember, no one will compensate you for material losses after incorrectly connecting the battery, because such a case is not covered by warranty.

How to connect a battery of a different polarity

You need to install exactly the batteries on your car that it is designed for. But if for some reason it is necessary to connect a battery of a different polarity, do this by extending one of the suitable wires. Just remember, such a “trick” can only be safely performed with a negative contact (since it is a ground). Extending the positive wire can lead to dire consequences.

What happens if you reverse the polarity?

If you mixed up the terminals when connecting, but quickly came to your senses and disconnected the battery, consider yourself lucky. Otherwise, such an oversight will lead to problems.

• Short circuit. If successful, you will only see sparks and hear electrical clicks. If the contacts are not immediately disconnected, the wires will begin to melt and smoke. With a quick reaction, the maximum that awaits is blown fuses.
• Fire. The output current from the battery is 55-60 A. This is enough for small wires to begin to melt and cause gasoline vapors to ignite.

For the battery, such “experiments” also do not go unnoticed. Although the new battery is unlikely to be damaged, the positive plates in the old one are likely to fall off, which will reduce the battery power and will no longer be enough to start the engine.

By the way, in most cases it will not be possible to connect the negative wire to the positive terminal without using a hammer. Manufacturers deliberately make the diameter of the positive contact slightly larger to minimize the number of such problems.

Currently, it is the contacts of “European” batteries that are standard.

In addition to the fuses described above, you can also burn:

• on-board computer (or electronic control unit);
• a diode bridge installed to protect the generator from such “problems”;
• alarm, or rather the triggers that are needed for its operation;
• wires on which there is a load (any wires, not just those suitable for the battery).

If the charger is connected incorrectly, the charger itself will most likely suffer: in expensive models the fuses will burn out, while a cheap Chinese device may burn out completely.

If you connect the contacts incorrectly when lighting a cigarette, a short circuit is guaranteed. To minimize the consequences of an error, the wires must be disconnected within 1-2 minutes (during this time they will heat up and begin to melt, and this can lead to a fire).