Solarity Product

How a solar panel charges a battery

Solar panels have been a major source of low-emission energy. Unlike other sources of energy that can cause hazards, In this article, we will look at how a solar panel charges a battery and the basic components involved.

To charge the battery, the solar panel transforms sunlight into DC current. A solar regulator, which makes sure the battery is charged correctly and that is not destroyed, supplies the battery with this DC current. While AC appliances need an inverter to convert the DC electricity into 240 Volt AC power, DC equipment can be powered directly from the battery. It is possible to connect some DC appliances to the regulator in order to benefit from the Low Voltage Disconnect and safeguard your battery.


Solar cells


In terms of Watts, solar panels are categorised based on their rated power production. According to this rating, the solar panel should be able to generate this much power during one peak sun hour. The average peak solar hours per day vary depending on where you are in the world. The numbers in Australia range from 3 in Tasmania to over 6 in parts of QLD, NT, and WA. For instance, the annual average in parts of the Hunter Valley in NSW is about 5.6. Throughout this region, the monthly values range from 4.0 or less in June to 6.5 or more in December.


This implies that an 80W solar panel might optimally produce about 320W per day in June and about 520W per day in November, but based on the average number of 5.6, it would provide an average of about 450W per day throughout the year…without accounting for losses. To boost voltage or current, solar panels can really be wired in series or parallel. A regulator is used to lower the 12 Volt solar panel’s rated terminal voltage, which is often approximately 17.0 Volts, to the required 13 to 15 Volts for battery charging.


The temperature at which solar cells are working has an impact on their production. A nominal temperature of 25 degrees Celsius is the rating for panels. Every 5 degrees of temperature difference can be anticipated to cause a 2.5 percent variation in the output of a conventional solar panel. The output declines as the temperature rises. In light of this, it is important to keep in mind that it is possible to go above a panel’s rated output if the panels are very cool from cloud cover and the sun suddenly breaks through. 


Solar controllers


Charge controllers, another name for solar regulators, are used to manage the flow of electricity from solar panels so that batteries don’t overcharge. Overcharging damages the batteries by causing electrolyte loss and gassing.


When the batteries are fully charged, a solar regulator detects this and reduces or stops the power flowing to the battery.

Most solar regulators also have a Low Voltage Disconnect feature that, in the event that the battery voltage drops below the cut-off voltage, turns off the supply to the load. By doing this, the battery’s potential for irreparable harm and shorter lifespan is avoided. A solar regulator also stops the battery from flattening out at night when it backfeeds into the solar panel. The maximum amount of current that solar regulators can accept from the solar panels determines their rating. For details on how to properly size a solar regulator, see the section below.


Information on Solar Regulator Sizing


The highest current that solar panels are capable of producing must always be supported by a solar regulator. A solar panel’s output current may rise by up to 25% above its rated voltage current in response to reflected sunshine and particular ambient temperature. It is necessary to size the solar regulator to accommodate the growing current. When controlling, solar regulators frequently short the solar panel input. This does not harm the solar panel, but it really does require that the regulator be sized to handle 125 percent of the short circuit current that the solar panel is rated to manage.


Solar batteries with a deep cycle


Unlike normal automobile batteries, which are made to deliver a lot of current for a short period of time, deep cycle batteries used in solar power systems are made to be depleted over a lengthy time (such as 100 hours) then recharged multiple times. Deep cycle batteries shouldn’t be depleted past 70% of capacity to ensure long battery life. i.e., 30% of the available capacity. The life of something like the batteries will be considerably shortened by discharges above this point.


Ampere Hours are used to rate deep cycle batteries (Ah). A discharge rate is also included in this grade, typically at 20 or 100 hours. This rating indicates how many amps of electricity the battery is capable of supplying over the stated number of hours.


For instance, a battery with a 120Ah rating at a 100-hour rate can deliver a total of 120A throughout that time. The equivalent current would be 1.2A every hour. The same battery could deliver 110Ah at the 20 hour rate, or 5.5A per hour for 20 hours, due to some internal heating at higher discharge rates. In actual use, this battery could power a 60W 12VDC TV for more than 20 hours before running out of power.


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