What is the battery charge controller. Li-Ion battery charge controller

The controllers themselves are useful devices. And to better understand this topic, it is necessary to work with a certain example. Therefore, we will consider the battery charge controller. What is he like? How is it arranged? What features of the work exist?

What does the battery charge controller do?

It serves to monitor the restoration of energy losses and waste. First, it is engaged in monitoring the conversion of electrical energy into chemical energy, so that in the future, if necessary, supplying the required circuits or devices. It is not difficult to make a battery controller yourself. But it can also be extracted from power supplies that are out of order.

How the controller works

Of course, there is no universal scheme. But many in their work use two poshodrachnye resistor, which regulate the upper and lower limit of voltage. When it goes beyond the specified limits, interaction with the relay windings begins, and it turns on. As long as it works, the voltage will not drop below a certain, technically predetermined level. Here you should talk about the fact that there is a different range of boundaries. So, for a battery, three, five, twelve, and fifteen volts can be set. Theoretically, everything depends on the hardware implementation. Let's look at how the battery charge controller works in different cases.

What are the types

It should be noted a significant variety, which can boast of the battery charge controllers. If we talk about their types, let's make a classification depending on the scope of application:

1. For renewable energy sources.
2. For household appliances.
3. For mobile devices.

Of course, the species themselves are much larger. But since we are considering the battery charge controller from a common point of view, then we will have enough of them. If we talk about those used for solar cells and windmills, then the upper limit of the voltage is usually 15 volts, while the lower limit is 12 V. The battery can generate in the standard mode 12 V. The power source is connected to it using normal Closed relay contacts. What happens when the battery voltage exceeds the set value of 15 V? In such cases, the controller closes the relay contacts. As a result, the source of electricity from the battery is switched to a load ballast. It should be noted that he is not particularly fond of putting on solar panels because of certain side effects. But for wind generators they are mandatory. Household appliances and mobile devices have their own characteristics. And the controller charge the battery tablet, touch and button cell phones are almost identical.

Let's take a look at the lithium-ion battery cell phone

If you unzip any battery, you can see that a small printed circuit board is soldered to the terminals of the cell . It is called a protection scheme. The fact is that lithium-ion batteries require constant monitoring. A conventional controller circuit is a miniature circuit board on which a circuit made of SMD components is based. It, in turn, is divided into two chips - one of them is the control one and the other is the executive one. Let's talk in more detail about the second.

Implementing scheme

It is based on MOSFET transistors. Usually there are two. The chip itself can have 6 or 8 pins. For separate control of charge and discharge, the battery cells use two field-effect transistors, which are in the same housing. So, one of them can connect or disconnect the load. The second transistor does the same, but with a power source (which is the charger). Thanks to this implementation scheme, it is possible to influence the operation of the battery without any problems. If desired, you can use it in another place. But it should be borne in mind that the circuit of the battery charger controller and it can only be applied to devices and elements that have a limited range of operation. More details about these features, we now talk.

Protection against overcharging

The fact is that if the voltage of the lithium battery exceeds 4.2, then overheating and even an explosion may occur. For this purpose, elements of microcircuits are selected that will stop charging when this indicator is reached. And usually, until the voltage reaches a value of 4-4.1 V due to use or in the process of self-discharge, further charging will be impossible. This is an important function that is entrusted to the lithium battery charge controller.

Protection against overdischarge

When the voltage reaches critical values, which make it difficult for the device to function properly (usually a range of 2.3-2.5V), the corresponding MOSFET transistor is turned off, which is responsible for supplying current to the mobile phone. Then there is a transition to sleep with minimal consumption. And here there is a rather interesting aspect of the work. So, until the battery cell voltage becomes more than 2,9-3,1 V, the mobile device can not be turned on to work in the usual mode. Probably, this you could notice that when you connect the phone, it shows that charging is in progress, but he does not want to turn on and operate normally.

Protective mechanisms

It should be noted that the battery charge controller has a number of elements that must be protected from negative consequences. So, it's parasitic diodes that are placed in the field effect transistors, a charge detection circuit and a few more small additions. Oh, yes, and if there is an opportunity to check the battery charge controller and find out the efficiency of the energy source, its functioning can be restored even at "death". Of course, this means simply stopping work, and not an explosion or meltdown. In this case, special devices can help, which carry out special "restorative" charging. Of course, they will work for a long time - the process can last for tens of hours, but after a successful completion the battery will work almost like a new one.

Conclusion

As you can see, the Li-Ion battery charge controller plays an important role in ensuring the durability of mobile devices and positively affects their service life. Due to the simplicity of production, they can be found in virtually any phone or tablet. If there is a desire to see with your own eyes, and touch the Li-Ion battery charge controller and its contents with your hands, then when parsing, you should remember that the work is done with a chemical element, so you need to be very careful.