Nowadays, batteries are the most common power sources for electronics and small equipment. The need to replace them arises quite often. In order to make the best choice when buying a new galvanic cell, you should pay attention not only to the size of the batteries and the name of the manufacturer. This article will answer the following questions: what form are these power sources? What are the types of batteries in size? How are galvanic cells labeled and what should I look for when buying in order for the power supply to last a long time?
Types of batteries
The classification of batteries is carried out depending on the materials from which their active components are made: anode, cathode and electrolyte.
There are five types of modern power supplies:
- salt
- alkaline
- mercury
- silver
- lithium.
The types of batteries in size will be listed below. And now we will consider in detail each of the indicated classes of galvanic cells.
Salt batteries
Salt batteries were created in the second half of the twentieth century. They replaced the previously existing manganese-zinc power sources. The dimensions of the batteries have not changed, but the manufacturing technology of these galvanic cells has become different. In salt power sources, a solution of ammonium chloride is used as the electrolyte. It contains electrodes made of zinc and manganese oxide. The connection between the individual electrolytes is carried out using a salt bridge.
The main advantage of such batteries is their low cost. These galvanic batteries are the cheapest among all existing ones.
Disadvantages of salt batteries:
- during the discharge period, the voltage decreases significantly;
- the shelf life is small and is only 2 years;
- by the end of the guaranteed shelf life, the capacity is reduced by 30-40 percent;
- at low temperature, the capacity decreases to almost zero.
Alkaline batteries
Such batteries were invented in 1964. Another name for these food sources is alkaline (from the English word alkaline, which means “alkaline” in translation).
The electrodes of such a battery are made of zinc and manganese dioxide. The alkali is potassium hydroxide.
Today, it is these batteries that are the most common, because they are great for most electronic devices.
Advantages of alkaline power sources:
- have a larger capacity in comparison with salt and, as a consequence, a longer service life;
- can work at low ambient temperature;
- have improved tightness, that is, the likelihood of leakage is reduced;
- have a longer shelf life, which is 5 years;
- have a reduced self-discharge rate compared to salt batteries.
Disadvantages of alkaline power sources:
- the discharge period is characterized by a gradual decrease in the output voltage;
- Alkaline batteries are similar in size to salt batteries, but the cost and weight of alkaline power sources are higher.
Mercury batteries
In such a battery, the anode is made of zinc, the cathode is made of mercury oxide. The electrodes are separated by a separator and a diaphragm, which is impregnated with a 40% potassium hydroxide solution. Alkali is used here as an electrolyte. Thanks to this very composition, this power source can work as a battery. But during cyclic operation, the galvanic cell degrades, its capacity decreases.
Advantages of mercury batteries:
- stable voltage;
- high capacities and energy density;
- the ability to work both at high and at low ambient temperatures;
- long shelf life of 10 years.
Disadvantages of mercury power supplies:
- high price;
- Possibility of hazardous effects of mercury vapor in case of depressurization;
- the need to establish a collection and disposal process.
Silver batteries
In a silver battery, zinc is used to produce the anode, and silver oxide is used for the cathode. The electrolyte is sodium or potassium hydroxide.
This category includes watch batteries, the sizes of which will be given below. The advantages of silver power supplies are as follows:
- voltage stability;
- the presence of high capacitance and energy density indicators;
- immunity to ambient temperature;
- long service life and storage.
The disadvantage of such batteries is their high cost.
Lithium batteries
In such a battery, the cathode is made of lithium. It is separated from the anode by a separator and a diaphragm, which is saturated with an organic electrolyte.
Advantages of lithium batteries:
- constant pressure;
- high capacity and energy density;
- independence of energy intensity from load current;
- light weight;
- long shelf life, which is up to 12 years;
- immunity to temperature extremes.
The disadvantages of lithium batteries can be attributed only to their high cost.
As indicated above, power supplies have different chemical composition. The shapes and sizes of the batteries also differ significantly from each other. Galvanic cells have different heights, diameters and voltages. Consider the classification of batteries in accordance with these parameters.
Size classification of batteries
Depending on the voltage, height, diameter and shape, power supplies can be systematized in a certain way. One of the most popular classification systems is American. It is presented in the figure below. This standardization is convenient, it is used in many countries.
According to the American system, power supplies are classified as follows:
Title | Height mm | Diameter mm | Voltage |
D | 61.5 | 34.2 | 1,5 |
|---|
C | 50,0 | 26.2 | 1,5 |
|---|
AA | 50,5 | 14.5 | 1,5 |
|---|
AAA | 44.5 | 10.5 | 1,5 |
|---|
PP3 | 48.5 | 26.5 | 9.0 |
|---|
In addition to the class indicated in the table, power supplies also have a common name, which is used by the people. For example, the size of an AA battery is comparable to the size of a human finger, so the “popular” name for this galvanic cell is a “finger” battery, or “two A” batteries. But the power source C is called in everyday life "inch". The galvanic cell D is called a “barrel”. And the AAA battery, the sizes of which are similar to the parameters of the smallest finger of a person, is not in vain called "little finger", or "three A". The PP3 power source is called the “crown”.
Also in electronics, miniature round batteries are widely used, the sizes and names of which are manifold. More detailed information on silver “pills” and a classification of such power sources are given below.
Batteries "tablets": sizes and names
Another name for a miniature round battery is a dry cell. Such power sources consist of an anode made of silver oxide, a zinc cathode and an electrolyte. The latter is a mixture of salts, which has a pasty consistency.
Different manufacturers often assign designations to such power supplies that differ from standard ones. The classification table below shows alternative names and sizes of watch batteries.
It is these miniature silver “tablets” that make the mechanisms of modern watches work. When it comes time to replace the battery, you may be faced with the question, what kind of power supply is suitable in this situation? For example, if the element 399 was used in the watch, you can replace it with a miniature battery, which, depending on the manufacturer, may have the names V399, D399, LR57, LR57SW, LR927, LR927SW or L927E. Under such names, a “tablet” will be produced, the height of which is 2.6 millimeters, and the diameter is 9.5.
The size of the batteries is not the only parameter that you should pay attention to when buying power supplies. In order to learn to decipher information that is located on galvanic cells, you need to familiarize yourself with the basic principles of their labeling.
Battery marking
The International Electrotechnical Commission (IEC) has created a specific notation system according to which all batteries should be marked. Information on its energy consumption, composition, size, class and magnitude of voltage should be indicated on the housing of the power source. Using the battery shown below, we’ll take a closer look at all the marking elements.
The information indicated on the power source indicates the following:
- the electric charge of the galvanic cell is 15 A * h;
- the class of the power source is AA, that is, it is a finger-type battery;
- voltage is 1.5 volts.
And what does the inscription "LR6" mean? This, in fact, is the marking that gives information about the chemical composition and class of the power source. The types of batteries have the following letter designations:
- salt - R;
- alkaline - LR;
- silver - SR;
- lithium - CR.
The classes of batteries are indicated by the following numbers:
- D is 20;
- C is 14;
- AA - 6;
- AAA - 03;
- PP3 - 6/22.
Now you can decipher the marking LR6 in the figure. The letters here indicate that it is an alkaline cell, and the number indicates the size of the “finger” battery, that is, indicates the power source belongs to class AA.
Scope and features of the choice of batteries
First of all, it should be noted that all galvanic cells meet the requirements of unification, that is, the consumer can easily replace the power supply of one manufacturer with a similar battery of another. There is only one caveat: do not use current sources made by different companies or all the more related to different types in one device. This will significantly reduce battery life.
When choosing a power source, you need to pay attention to the packaging. Often, the manufacturer indicates on it devices in which it is recommended to use these batteries. If such information is not provided, the tips below will help you make the right choice.
Salt batteries have a low capacity of 0.6-0.8 A * h and are used in devices with low power consumption. It can be remote controls, electronic thermometers, testers, bathroom or kitchen scales. Salt elements can also be used as watch batteries. The sizes of such current sources are similar to the corresponding alkaline parameters, however, their areas of application vary significantly. After all, if you use salt batteries in devices with an electric motor, flashlights or cameras, then their service life can be as little as 20-30 minutes. Such galvanic cells are not designed for heavy loads.
Alkaline batteries have a sufficiently large capacity of 1.5-3.2 A * h. This allows you to successfully use them in devices that have increased power consumption. Such devices include flash digital cameras, flashlights, children's toys, office phones, computer mice, etc. Batteries designed specifically for cameras release energy faster. This has a positive effect on the speed of the cameras. If you use an alkaline power source in devices with low power consumption, the batteries will show excellent results, their service life will be several years.
Twenty to thirty years ago, mercury batteries were widely used in devices such as electronic watches, pacemakers, hearing aids, and military devices. To date, the use of these power sources is limited. In many countries, it is forbidden to manufacture and operate such galvanic cells because mercury is a toxic substance. In the case of using these current sources, it is necessary to organize their separate collection and disposal in accordance with safety requirements.
Silver batteries are not widely used due to the high cost of metal. However, miniature power supplies of this kind are widely used in watches, motherboards for laptops and computers, hearing aids, music cards, key rings and other devices where it is impossible to use larger batteries.
Lithium batteries have a longer life compared to even the best alkaline batteries. Therefore, such power sources are used in devices that have high power consumption. It can be computer and photo equipment, medical equipment.
Conclusion
A battery is a product that, despite its small size, can be dangerous. You can not disassemble the power source, throw it into the fire and, of course, try to recharge. On the net, you can find tips on how to give your battery a second life. Do not try to conduct such experiments, because it can be dangerous.
When buying new batteries, you should pay attention not only to the manufacturer and the appropriate size, but also to the chemical composition of the power sources. To do this, you must be able to read the markings. Properly selected batteries will last a long and high quality.