When buying a car battery, pay attention to the polarity. If the battery is not connected correctly, then the electrician of the machine may completely fail.
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What is battery polarity?
The direct current source has both positive and negative contact. They are connected to consumers of electricity. Finding out the polarity of the battery is easy. On the case there are plus and minus icons, often there are color codes.
In addition, the positive contact has a larger size. Most cars have a positive terminal of 19.5 mm and a negative terminal of 17.9 mm. Asian cars (Asia) have a plus terminal of 12.7 mm and a minus terminal of 11.1 mm.
Such features almost completely eliminate the possibility of incorrect battery connection. The location of the battery in a car is different. Under the hood to the right or left. In the cabin or trunk. Therefore, you should choose a device that will have the correct terminal layout.
Reverse Battery Polarity
Owners of foreign cars should be aware that almost all cars use batteries with reverse polarity, indicated by the number "0".
Visually determined can be as follows. If you position the battery so that the terminals and the label are facing the person, then on the right there will be a plus and on the left a minus.
For trucks, the reverse polarity is called left and is indicated by the number "3". The fact is that due to the large dimensions of the case, the terminals are installed on the narrow side. In order to determine the polarity you need to get up from the edge of the battery where the terminals are located. There will be a plus on the left, and a minus on the right.
Battery Direct Polarity
Direct polarity is used on domestic cars. In this case, the positive terminal is located on the left, and the negative terminal is on the right side. For cars, it is indicated by the number "1"
For trucks, the direct polarity is called the right and is indicated by the number "4". If you get up from the edge where the contacts are, then on the right side there will be a plus, and on the left there will be a minus.
Other types of polarity
There are more rare locations of the terminals, which can significantly complicate the identification procedure. For example, there are models having a polarity of “6”, which is visually determined by the presence of a positive terminal on the right, but the device’s case itself has an almost square shape.
The polarity is “9”, it is also “5” is also not very common. You can find out that the battery belongs to this category by the location of the terminals exactly in the middle of the battery.
There is also a polarity of “2”, it is also found on trucks and special equipment. In this case, the terminals are located diagonally.
How to determine forward or reverse polarity
Determine whether the battery belongs to one or another category, by the location of the terminals on the case. If the polarity is straight, then the plus is located on the left, with the reverse - the plus terminal is on the right. If the battery is old and the inscriptions are erased or closed under a large number of deposits, then using the arrow voltmeter, you can accurately determine where the positive terminal of the battery is located.
What happens if you reverse the polarity when connecting
If the terminals are mixed up during connection, the following consequences are possible:
- Blown fuses.
- Fire.
- Failure of the computer.
- Burnout of the diode bridge of the generator.
- Reflow wiring.
- Alarm failure.
The most dangerous phenomenon when reversing is a fire, so if sparks occur when connecting the terminals, the procedure should be stopped. Wiring can also be severely damaged.
Is it possible to reverse the polarity of the battery
It is not possible to change the location of the electrical terminals on the battery case, but on some vehicles it is possible to install a different type of battery. In this case, it is enough to turn the battery 180 degrees so that the corresponding conclusions coincide with the terminals.
This method of connecting the battery with the wrong location of the electrical terminals may not be suitable only for very short wires that come from the "mass" of the car and the engine generator. If on a car the wires connected to the battery are too short to install parts that are not suitable for the location of the terminals, then it is enough to replace them with a longer conductor. In this case, the diameter of the wire should not be less than the dismantled wiring element.
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