How to understand the forward and reverse polarity of a battery

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.

Battery polarity is forward and reverse. What are they and what is the difference between them?

We have already talked about what will happen if the battery terminals are mixed up. However, this may not happen on purpose, but rather, let’s say, due to inexperience. The thing is that domestic cars have direct battery polarity, while many foreign cars have reverse polarity (I’ll note right away not all of them). Novice motorists don’t know what polarity is, I’m already silent about how they differ. Today is a detailed article that will answer all your questions...

THE CONTENT OF THE ARTICLE

First, a little definition.

Polarity is the location of external current-carrying elements (current leads) on the front or top cover of the battery. The most common layouts are the so-called “direct” and “reverse”, but in fairness it should be noted that there are also very exotic arrangements of current leads, but as a rule they have not taken root in our country or in foreign countries.

In simple words, this is the location of the terminals - in some cases the positive one is on the right, and in other cases on the left. This is where the main difference lies.

Straight battery polarity

Direct (sometimes marked as “1”), this is a purely domestic development. It’s easy and simple to identify - take the battery, turn it towards you (facing it) so that the current leads are at the bottom (the label is in front of your eyes). If the positive terminal is on the left and the negative terminal on the right, this is straight polarity. Here's the diagram.

Such batteries are found on many domestic cars, for example on our VAZs, in particular on the Priora.

Reverse battery polarity

Reverse - marked as “0”, European development. It differs from the direct one by connecting the battery “cans”. Determine - turn the battery “face”, the current terminals are at the bottom, the label is in front of your eyes. If the negative terminal is on the left and the positive terminal on the right, this is reverse polarity. Let's look at the diagram.

Such batteries are found on many European cars, there are exceptions, but rarely.

How are batteries different?

The differences are minimal, except for the pole. I would like to note that externally the batteries are almost identical - that is, the body, the number of cans, the current strength, and even the label. And it is very easy to confuse the battery, that is, you can buy it with the wrong location of the current leads (terminals). Even an experienced driver can get into trouble if he makes a spontaneous choice. Therefore, if you yourself do not understand this, ask the seller to choose one for your car; as a rule, they have catalogs that describe suitable models. It will be best this way!

Therefore, if you are thinking about replacing the battery, you need to know exactly and determine the location of the terminals, this is extremely important!

Is it possible to set a different polarity?

I am often asked this question; it happens that newbies buy out of inexperience, often even installing and mercilessly “burning” their cars! Guys, if you mix up the terminals, then at a minimum your electronics may burn out along with the ECU, and at the very least you are not far from a fire. Therefore, compare at least with the old battery, don’t be lazy, you need to know exactly how your poles are located.

If you determine that you chose the wrong one, then you definitely need to change the new battery to the correct one! It is very important!

However, the following questions often arise: “I recognized it only after installation, the terminals were torn and even shorted a little, the store does not replace it under warranty. What to do? how to install?

The whole point is that you simply won’t have enough negative (positive) wire!

You need to either build it up, starting wires may come in handy, but all this is just hackwork! You may incorrectly calculate the wire cross-section.

Still try to sell this battery. Place an ad, write the reason for the sale, and then buy the right one! If it doesn’t sell, then there’s nothing to do, we buy another one, but it’s correct.

Now a short video comparing almost two identical samples.

I tried to talk about this phenomenon as simply as possible. That's all, I think you found the information useful. Read our AUTOBLOG.

( 23 votes, average: 4.35 out of 5)

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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).

Battery polarity forward and reverse: how to determine and what it affects

A modern battery does not require the owner to have any knowledge of the technology of its operation. Once installed in a car, it serves faithfully for its intended duration without additional maintenance.

Comparing a car battery with a regular battery is not entirely correct. When choosing a battery, you should keep in mind that any rechargeable battery has strict polarity, and where direct connection polarity is provided, it is difficult to install a battery with reverse polarity, and vice versa.

The polarity of the battery, forward and reverse, does not affect the performance properties of the battery at all, it is just the order of the contact pins on the device body. Therefore, in many cases, a battery of the same model can be produced in two versions.

If you prefer a certain brand of battery, check with the seller what polarities are available for this battery. What is the reverse and direct polarity of a battery, how to determine it, you can learn from this article.

What does direct or reverse polarity mean?

The polarity of the battery, as we mentioned above, can be reverse or direct. Direct polarity was developed for the needs of the Soviet automobile industry. And until now, all cars produced in Russia are equipped with batteries with straight polarity.

Reverse polarity, as you might guess, is used in European, American and Asian cars. The truth is that the car was assembled abroad does not always mean that its battery belongs to the “reverse polarity” group.

What is forward and reverse battery polarity? Direct polarity implies a positive terminal on the left and a negative terminal on the right; in the case of reverse polarity, the positive and negative terminals are swapped.

You should look at the battery from the front side; it can be identified by the label attached, and if there is no label, the front side is considered to be the side to which the terminals are located closest. If the red, positive terminal (can be indicated by engraving on the case) is on the right, then the battery has reverse polarity.

When to determine polarity

When purchasing a new battery, you need to understand exactly what polarity is on the battery. Installing a battery with a different polarity is sometimes possible by rotating it 180 degrees in the socket. But such manipulations will not allow the fastenings to be fully tightened.

In addition, so that the car enthusiast does not confuse the plus with the minus, the length of the wires is different, and it will be possible to connect the battery correctly only if the wires are extended so that they can reach the necessary terminals.

How to determine battery polarity

Every car owner should know how to determine the polarity of the battery. And not only when buying a new one, but also when recharging an old one, or before “lighting up” from someone else’s battery, in case of a low charge.

As a rule, batteries have clearly visible markings on the case, “plus” and “minus”, they are especially visible on domestically produced batteries. In batteries manufactured in Asia or Europe, the terminals are usually of different sizes, and the positive “+” is slightly larger in diameter than the “-”. This will prevent you from unknowingly or forgetfully installing the terminals incorrectly. There is also a practice of marking terminals with color: minus – black (less often blue), plus – red.

As a last resort, you can use an ordinary tester or voltmeter. A positive value will indicate that its positive contact is connected to the battery positive, and vice versa. Having found out the polarity, you can make a note for yourself, not only on the battery case, but also at the installation site. If you buy a new battery, this will serve you well and will save you from accidental damage to the car’s electrical equipment.

Straight battery polarity

Straight battery polarity, as we have already noted, is still the standard for all brands of cars produced in the countries of the former USSR, which is determined by the standards adopted by states. By the way, this applies equally to both passenger and freight transport.

Also, straight polarity is typical for foreign cars assembled in the Russian Federation and other countries under license. Its peculiarity is that the positive terminal is located on the left, and the battery, as a rule, has the same terminals.

Reverse battery polarity

The reverse polarity of the battery, accepted in the USA, Europe and Asia, is characterized by the right-side location of the positive contact. Note that such batteries from domestic manufacturers, as a rule, are well marked, while imported ones, if installed incorrectly, do not even match the diameter of the clamp on the terminals.

If you reverse the polarity

Connecting the battery without taking into account whether the battery polarity is straight or reverse will not damage most of the car's electronic devices, but some of them may still be damaged. For example, incandescent lamps will function with any polarity.

The starter simply will not be able to crank the engine in the opposite direction; rather, the relay will burn out, but in most cases, if the terminals are connected incorrectly, the “ratchet” will work. The situation is much more complicated with regular consumers of electricity.

When the polarity is changed, the car's generator becomes not a supplier, but a consumer of electricity, which can cause a breakdown; its winding is not designed for counter voltage. The battery may also fail.

In the best case, the corresponding fuse or limiting relay will burn out, which, one way or another, will cause unnecessary trouble and financial costs. Therefore, before starting the engine, you must make sure that the battery is connected correctly.

Electronic control unit

Being constantly connected to the network, except when the ground is disconnected, the ECU will most likely be damaged, since this electronic device requires strict power polarity. Considering that in modern cars the control unit is not even one device, there are several of them, troubleshooting can become more complicated.

Failure of the ECU makes the vehicle unusable. And, by the way, the electronic unit is one of the most expensive devices to diagnose. Its power supply is designed for low currents, so the fuse may simply not have time to burn out and break the circuit.

Therefore, an important note!

Disconnecting the ground before working with the battery! Make sure to connect the terminals correctly, so you will avoid many problems with the on-board computer!

Fuse box

This is the simplest and cheapest result of an incorrect battery connection. Fuses, as a consumable item, are inexpensive today, and the biggest problem for a self-taught auto mechanic will be finding a blown fuse. However, using a tester or an ordinary light bulb, “ringing” will take at most five minutes.

Please note that when using modern U-shaped fuses, it is better to give preference to those with a transparent body. The integrity of the metal thread is visible to the light, which is very convenient in the absence of a tester.

Conclusion

When choosing a new battery for your car, focus on its characteristics. This is the main selection criterion. If you prefer one brand, then, as a rule, there will be no problems with polarity. Ask the seller to help you choose exactly your model.

If you purchased a battery with the wrong polarity, return it back to the store. But if a return is not possible, then you can turn the battery 180° in the socket and extend the wires to the required length.

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.