How does the battery charge? Is the circuit of this device complicated or not, in order to make a device with your own hands? Is a car battery charger fundamentally different from what is used for mobile phones? We will try to answer all the questions posed later in the article.
General information
The battery plays a very important role in the functioning of devices, units and mechanisms that require electricity to operate. So, in vehicles, it helps to start the engine of the car. And in mobile phones, batteries allow us to make calls.
Charging the battery, the scheme and principles of operation of this device are considered even in a school physics course. But, alas, by the time of release, many of this knowledge has been forgotten. Therefore, we hasten to remind you that the operation of the battery is based on the principle of the occurrence of a voltage difference (potentials) between two plates, which are specially immersed in an electrolyte solution.
The first batteries were copper-zinc. But since then, they have improved and modernized significantly.
How it worksbattery
The only visible element of any device is the case. It ensures the generality and integrity of the design. It should be noted that the name "battery" can only be fully applied to one battery cell (they are also called banks), and there are only six of them in the same standard 12 V car battery.
Back to the body. It is subject to strict requirements. So, it should be:
- resistant to aggressive chemicals;
- capable of withstanding wide fluctuations in temperature;
- with good vibration resistance.
All these requirements are met by a modern synthetic material - polypropylene. More detailed differences should only be highlighted when working with specific samples.
Working principle
Let's take lead-acid batteries as an example.
When there is a load on the terminal, a chemical reaction begins to occur, which is accompanied by the release of electricity. Over time, the battery will drain. How is she recovering? Is there a simple circuit?
Charging the battery is not difficult. It is necessary to carry out the reverse process - electricity is supplied to the terminals, chemical reactions occur again (pure lead is restored), which will allow the battery to be used in the future.
Density also increases during chargingelectrolyte. Thus, the battery restores its initial properties. The better the technology and materials that were used in the manufacture, the more charge / discharge cycles the battery can withstand.
Which battery charging circuits are there
The classic device is made from a rectifier and a transformer. If we consider all the same car batteries with a voltage of 12 V, then the charges for them have a constant current of about 14 V.
Why is that? This voltage is necessary so that current can flow through a discharged car battery. If he himself has 12 V, then a device of the same power will not be able to help him, therefore, they take higher values. But in everything you need to know the measure: if you overestimate the voltage too much, this will adversely affect the life of the device.
Therefore, if you want to make a device with your own hands, it is necessary for cars to look for suitable car battery charging schemes. The same applies to other technology. If you need a lithium-ion battery charging circuit, then you need a 4 V device and no more.
Restoration process
Let's say you have a circuit for charging a battery from a generator, according to which the device was assembled. The battery is connected and the recovery process starts immediately. As it flows, the internal resistance of the device will increase. Along with it, the charging current will drop.
When the voltage approaches the maximum possiblevalue, then this process practically does not proceed at all. And this indicates that the device has successfully charged and can be turned off.
Technological recommendations
It is necessary to ensure that the battery current is only 10% of its capacity. Moreover, it is not recommended to either exceed this indicator or reduce it. So, if you follow the first path, the electrolyte will begin to evaporate, which will significantly affect the maximum capacity and battery life. On the second path, the necessary processes will not occur at the required intensity, because of which the negative processes will continue, although to a somewhat lesser extent.
Charging
The described device can be bought or assembled by hand. For the second option, we need electrical circuits for charging batteries. The choice of technology by which it will be done should depend on which batteries are the target. You will need the following components:
- Current limiter (designed on ballast capacitors and transformer). The greater the indicator can be achieved, the greater the magnitude of the current will be. In general, this should be enough for charging to work. But the reliability of this device is very low. So, if you break the contacts or mix something up, then both the transformer and the capacitors will fail.
- Protection in case of connection of "wrong" poles. To do this, you can design a relay. Yes, conditionalbased on a diode. If you confuse plus and minus, then it will not pass current. And since a relay is tied to it, it will be de-energized. Moreover, you can use this circuit with a device based on both thyristors and transistors. It must be connected to a break in the wires, with the help of which the charging itself is connected to the battery.
- Automatic, which should have battery charging. The circuit in this case must ensure that the device will work only when there is really a need for it. To do this, with the help of resistors, the response threshold of the controlling diode is changed. 12V batteries are considered to be full when their voltage is within 12.8V. Therefore, this figure is desirable for this circuit.
Conclusion
So we looked at what constitutes battery charging. The circuit of this device can be made on a single board, but it should be noted that this is quite difficult. Therefore, they are made multi-layered.
As part of the article, various schematic diagrams were presented to your attention, which make it clear how, in fact, the batteries are charged. But you need to understand that these are only general images, and more detailed ones, with indications of ongoing chemical reactions, are special for each type of battery.
