Typically, a 200w solar panel system will take 5-8 hours to complete the full charging process of a 12v battery. In order to compensate for the inability of solar panels to deliver normal power at night and during inclement weather, solar systems on the market today are equipped with solar cells for storing excess power produced by the solar panels during sunny daytime hours. In this article, we will analyses the specific length of time that a 200w solar panel can charge a 12v battery from various perspectives for you.
1. What is a 200w solar panel system and what is a 12v solar battery?
First of all, we need to know that the size of the solar panel system on the market is generally graded according to the rated power generation. 200w solar panel system refers to the solar system that can generate power up to 200w, i.e., 200Wh per hour under the optimal lighting conditions.
A 12v solar battery is an energy storage device used in a solar system to retain excess power and to ensure that you continue to receive power when the solar panels stop supplying electricity. Generally, the 12v solar battery used in the market are deep cycle batteries, which are more adaptable to multiple charge/discharge cycles than ordinary batteries, without decreasing efficiency. And its power supply is stable, do not need to provide a rapid burst of energy to power like ordinary batteries, these performance characteristics make it an ideal choice for solar battery.
2. What are the steps required to charge a 12v solar battery?
Charging a 12v solar battery is divided into three main phases, which are: the high-capacity charging phase, the small capacity absorption phase, and the automatic maintenance phase.
Large Capacity Charging Stage
When the battery is first connected to the power supply to start charging, the power supply, that is, the solar panel will maintain the maximum delivery voltage to continuously charge the battery. During this phase, the solar charge controller will keep the charging voltage at a constant level to maintain high capacity fast charging.
Small Capacity Absorption Stage
After the end of the large capacity charging stage, the charging voltage of the battery will continue to drop, and as the charging voltage level drops, the internal resistance of this battery will continue to increase and finally peak as the battery capacity continues to increase. The average charging voltage during this period is small, and its charging capacity percentage is also small in the whole charging process.
Automatic Maintenance Stage
At the end of the small capacity absorption phase, the battery is actually fully charged, but considering that the user cannot learn this information in time, the battery enters the automatic maintenance phase. The charge controller allows only a small amount of power to enter the battery to ensure that the battery capacity is maintained at 100%, while the battery is naturally discharged to achieve a balance between charging and discharging, preventing overcharging phenomenon resulting in battery damage.
3. How to calculate how long it takes to charge a 12v solar battery for a 200w solar panel system?
After understanding the charging steps of 12v battery, we can start to calculate the time needed to charge 12v solar battery for 200w solar panel system.
In a nutshell, the charging time for a solar battery depends largely on the capacity of the battery and the power rating of the charging power source, and these calculations will involve: ampere hours, watts, and volts.
An ampere-hour (Ah) is a unit of energy. 1Ah is the amount of energy that a battery can release while holding an output current of 1A for 1h. It is often used as a unit of measurement for battery capacity.
And watt (w) is the unit of power, the watt value of a solar panel is the amount of power generated by the solar panel under ideal conditions. Its relationship to the charging current is:
The volt (v) is the unit of voltage, and it is used to describe the amount of vigorous force that drives the current in a charging circuit. It can also be used to describe the magnitude of the electrical potential of a battery.
After learning the above physical quantities, we can calculate the time required to charge a 12v solar battery from a 200w solar panel according to the formula, first:
Ah = P (w) ÷ V (v)
In the above formula Ah is the capacity of the solar battery, P is the rated power of the solar battery and V is the output voltage of the battery. From this, we can calculate the amp-hour rating of a 12v battery. It is worth noting that the specific amp-hour rating will also make some difference because the power rating of 12v solar battery on the market is not the same.
Then, based on the output power of the solar charger, you can calculate the number of hours to charge the solar battery:
T (h) = E (Ah) ÷ I (A)
I in the above formula refers to the charging current of the solar panel, and T refers to the time needed to charge the battery using the solar panel system.
In order for you to better understand the formula, the following is an example of a 200w solar panel capable of emitting a 2A charging current, when the capacity of this 12v solar battery is 16Ah, the charging time will be 16Ah ÷ 2A = 8h.
However, in practice, the specific charging time will be affected by a variety of environmental factors, including the abundance of sunlight resources, the quality of the solar panel, the output efficiency of the charge controller, and the health status of the battery, and so on.
4. What factors affect the charging time of a 12v battery?
Based on the formula above, it is clear that the charging time of a 12v battery is mainly affected by the battery amp-hour rating, the output of the solar panel, and the length of peak sunlight at the location.
Battery Amp Hour Rating
The amp-hour rating is the capacity of the battery. There are a variety of 12v solar batteries available on the market, and while the charging time of a battery increases as the battery capacity increases, the charging speed is not the main factor in choosing a solar battery, but rather the capacity of the battery based on the amount of energy you need to store, the amount of energy your solar panel system will produce, and the length of peak sunlight in your area.
Output of solar panels
The output of the solar panels will significantly affect the charging time of the batteries, provided that the battery capacity is equal. For example, a 200W solar panel system requires much less charging time than a 50W solar panel system. This increase in charging efficiency should also be taken into account and may encourage you to build a larger solar panel system.
Peak sunlight hours
Provided that the battery capacity is equal and the rated output of the solar panel system is equal, the length of peak sunlight in the location can have a significant impact on the charging time. Before you plan to build a 200w solar panel system, it is best to evaluate the surrounding tall buildings and potential shading before deciding whether you need to further expand the size of your solar panel system.
Summary:
Under ideal conditions, it takes about 5-8h to charge a 12v solar battery using a 200w solar panel system, but the exact charging time will be affected by a number of factors such as the battery capacity, the output capacity of the solar panels, and the length of peak sunshine in the location. In order to achieve a faster charging speed, we recommend that you try to keep the solar panel facing the sunlight when charging the 12v batteries and minimize nearby shading.
