Summary： There exist so many types of battery charging technologies in the market and in this article, we are going to put our focus on the types of battery chargers and power sources for the battery charger.
Batteries are power storage devices. These devices gain power from several sources ranging from solar and electricity grids. The power stored in the batteries is consumable and therefore it needs to be reloaded once consumed. Most batteries are used as backup systems where they are utilized anytime there is no power source connection, such as during blackouts. In some applications such as electric cars, loan more, etc, the battery is used to drive the system. To charge a battery, you need a charging system that consists of the power source and the charger. In this article, am going to introduce the types of battery chargers an engineer or a technician should be equipped with for the charging process of the various batteries to be successful. Every type of battery cell has a designated type of charger that should be used. Let us walk together.
Chargers have some electronic mechanism for carrying out voltage regulation which controls the voltage that is subjected to the charging battery. Therefore, there is a confidential choice of charging circuit that should be done and this is what delivers the quality to the battery. Below is a discussion of some examples of charging circuits that can be employed.
This type of charger employs the technology of PWM to control the flow of voltage. It is too complex but with higher efficiency compared to linear regulators. The charger requires a large capacitor and inductor circuit to smoothen the delivered pulsed waveform. Its components are built depending on the required current but can be reduced by the use of a very high switching frequency ranging between 50kHz and 500kHz.
These are mostly used in photovoltaic systems because they are cheap and simple to utilize and design. The current of charging is controlled using a transistor or a switch that is connected parallel to the PV panel and the battery for power storage. The overcharging of the battery is avoided through the shunting of the transistor and the PV output when the predetermined voltage limit is attained. The shunt also protects the photovoltaic panel against damage that can originate from reverse voltage anytime the battery voltage exceeds the supply voltage of the photovoltaic panel.
Figure 1: Circuit Diagram of Shunt Regulator Charger by Simon Mugo
Too noisy but very simple to build. Such types of chargers need to be built around a heat sink to help in the dissipation of generated heat by components connected in series. All the current of the load is passed through a higher-power transistor. The charger has np switching and hence the DC power produced is very clean no need for the filtering system. This is the same reason why there is no radiated or emitted electrical noise from the system. The charger is suitable for radio and low-noise codeless applications. Few components make them very tiny.
Figure 2: Transistor Series Regulator by Simon Mugo
Anytime you come across a switching regulator that makes use of the step-down DC-DC converter, then that system is referred to as a buck regulator. Such regulators have the advantages of very negligible heat loss and high efficiency. They generate very low RF interference and can survive under high output currents as compared to the normal switch mode chargers. Utilize a very tiny output filter and the design does not make use of the transformer.
Figure 3: Simple Buck Regulator Circuit by Simon Mugo
USB stands for Universal Serial Bus. It is a system of charging batteries that was introduced by peripheral devices and computer manufacturers to replace tiresome electrical and mechanical interconnections used in the transferring of data between external devices and computers. It includes two data wires connection, a 5v power line, and a ground connection. There exist several types of USB chargers categorized from data to fast chargers and type A to type C.
Figure 4: USB Connection Circuit by Simon Mugo
This makes use of a series of connected transistors that can be switched. When the battery voltage is low, the transistor is always in the ON condition hence conducting the source voltage directly into the battery cells for storage. When the battery storage capacity approaches the predetermined regulation voltage, there is the pulsing of the input current by the series transistor to help maintain the level that is desired. Smaller output filters are utilized. The system experiences smaller heat problems. The pulsing process is very necessary because it allows the battery to have to stabilize time. The process allows faster charging and boosting of batteries.
Any time you are specifying the type of charger you are going to make use of, then it is advisable that you also specify the source of the voltage that powers the particular charger. This is made possible by considering efficiency losses, availability of the power source, and power ranges of the charger. Below are some of the power sources necessary for charging systems.
This includes power sources such as the AC mains, regulated DC battery Supply, and special chargers. AC mains are good for universal chargers that are to be used in the international market such as charging computers, mobile phones, and home appliances such as refrigerators. A regulated DC battery supply is always provided for special use such as for custom applications and mobile production equipment. Special chargers are employed in portable sources of power such as solar panels.
This is the state of charging the battery any moment there is the availability of power or in between incomplete discharges instead of waiting for a complete battery discharge. This is good for batteries used in the cycle service. The technology is good in inductive chargers, solar power, onboard vehicle chargers, and wind power.
The method is suitable for specified cell chemistries and is good for some high-power batteries such as zinc-air, and flow batteries. It happens in minutes and it is so quicker than the conventional reversible method.
For a charger to perform better during the charging of the battery, there are specifications that the charger must meet.
· Output Voltage Purity: the charger should have the ability to deliver clean, purified, and regulated voltage. This means the voltage should not have spikes, ripples, or noise at all.
· Efficiency: High power batteries there should not be significant energy loss on the charger to limit the charging time. The charger should be of high efficiency of up to 90%
· Power factor: The charger should have an excellent power factor
· In-rush currents: The initial switching current might be higher than the maximum specified charging current. The charger should be designed to limit this in-rush current.
