What is a terminal
A terminal is a kind of fixture. Its purpose is to provide a strong connection between the two ends of the electrical wiring to each other or at the power source. In connection with cars, battery terminals are most often referred to.
They are made of metals with increased current conductivity. The stability of the electronics depends on the quality of these elements. Due to constant exposure to moisture in the air, they can oxidize.
What terminals are there and how to protect them from oxidation?
The types of battery terminals depend on:
- battery polarity;
- installation diagrams;
- forms of connection;
- material of manufacture.
Car batteries provide constant current. Therefore, polarity is essential when connecting the electrical circuit. Contact "+" cannot be directly connected with "-".
In batteries for cars, the contacts are located on different sides of the case. Truck versions are equipped with contacts on one side. All batteries differ in the location of the output contacts.
- Direct polarity. Such batteries are installed in domestic car brands. In them, the positive contact is on the left, and the negative contact is on the right (Fig. 1 and 4).
- Reverse polarity. In foreign cars, a variant is used with the opposite (compared to the previous modification) arrangement of contacts (Fig. 0 and 3).
In some batteries, the terminals are connected diagonally. The clamping contacts can be straight, or bent to the side (to prevent accidental contact). Pay attention to their shape if you use a battery with limited space near the contacts (Fig. Europe).
The most common wiring diagram for the electrical system is from the top of the battery. To prevent the motorist accidentally confusing the polarity and spoiling the equipment, the contacts on the batteries have different diameters. In this case, when connecting the wires, the owner of the car will not even be able to put the terminal on the output contact of the battery.
When buying a car overseas, you need to make sure the battery is European (not Asian). If the terminal on such a battery fails (oxidizes or breaks), it will be difficult to find a replacement for it, and the battery will have to be changed.
These types of batteries can be of different sizes and therefore are not suitable for installation in the engine compartment of a car. Therefore, cars for the Asian market are not sold in our region and vice versa.
The shape and dimensions of the terminals
Before buying a new pair of terminals, you need to pay attention to the shape of the battery contacts. Most car batteries sold in the CIS countries are equipped with cone-shaped contacts. Naturally, an even terminal in this case will have a smaller contact area. As a result, the electrical circuit is broken due to the oxidized compound.
Some battery contacts have a bolt-on terminal (truck options) or a screw terminal (common in North America). You should pay attention to this when buying a car on American Internet sites.
If it happens that the motorist has purchased a car with a non-standard battery connection, you can buy a special terminal adapter or self-clamping modifications.
There are four types of battery terminals.
- Lead. The most common type of connectors. They are equipped with a bolt clamp. Disadvantage - the material melts at a low heating temperature (327 degrees). However, in the event of a short circuit (if the wiring does not have time to burn out), it will act as a fuse. Such terminals are characterized by increased strength when crimping contacts. Another disadvantage is lower conductivity compared to copper and brass counterparts.
- Made of copper. This type of clamps is rarely used on car batteries due to the high cost and laborious manufacturing process. Copper is an excellent conductor of electricity. It doesn't oxidize as quickly. It is worth considering that this category of terminals mistakenly includes steel modifications with a copper coating.
- Made of brass. This type of terminal is highly resistant to moisture, which makes oxidation very slow. They are simple to install, but easy to bend and break if you apply force while tightening the bolts.
- Made of bronze. The material is similar to brass, but more durable.
Which terminals should you choose?
The easiest option is to buy the type of terminals that are installed in the car at the factory. In this case, there will be no installation problems.
If it is necessary to replace the standard terminals due to their impracticality, then it is better to choose the lead version. They will cost less, and in terms of strength they are better than their bronze and brass counterparts.
Copper ones are ideal because they oxidize less and can be bolted tightly. However, they are more difficult to find and will cost an order of magnitude more.
How to prevent oxidation?
Regardless of the material, all terminals will sooner or later begin to oxidize. This is a natural process when metal is exposed to humid air. Due to poor contact on the battery in the electrical system of the machine, sudden voltage surges can occur (this effect occurs when the voltage is restored and is often accompanied by arcing). To prevent expensive equipment from malfunctioning, it is necessary to regularly service the contacts on the terminals.
To do this, it is necessary to periodically disconnect them and remove plaque on the inside of the crimps. This procedure should be performed even if the car is in a dry garage, because the formation of plaque can be caused by a chemical reaction when parts are heated and exposed to electricity.
Some motorists perform this procedure by slightly loosening the fixing bolts and turning the terminal on the contact itself several times. These steps will help restore power, but the lead cells will become unusable faster. It is much better to clean the contacts with alcohol-soaked wipes.
So, battery terminals are a simple but important element of a car's electrical circuit. With proper care and proper installation, they will ensure the stable operation of all machine equipment.
How to properly remove and then put on the terminals from the battery, see the following video: