1. Solar panel efficiency: Solar panel efficiency refers to the percentage of sunlight that is converted into electrical energy. Typical solar panel efficiency ranges from 15% to 20%. For this calculation, let's assume an efficiency of 17%.
2. Battery capacity: Battery capacity is measured in amp-hours (Ah) and indicates how much electrical charge the battery can store. For this example, let's assume the deep-cycle battery has a capacity of 100 Ah.
3. Solar irradiance: Solar irradiance refers to the amount of sunlight reaching the solar panel's surface. The irradiance level varies based on factors like time of day, location, and weather conditions. For this calculation, let's assume an average irradiance of 1,000 watts per square meter (W/m²).
4. Charging current: The charging current is the amount of current flowing into the battery from the solar panel. To calculate the charging current, we need to consider the solar panel's maximum power output and the battery voltage. In this case, the solar panel's maximum power output is 135 watts, and the battery voltage is 12V. Therefore, the charging current is approximately 135W / 12V = 11.25A.
Now, we can calculate the charging time using the following formula:
Charging time (in hours) = Battery capacity (in Ah) / Charging current (in A)
Plugging in the values we have:
Charging time = 100Ah / 11.25A ≈ 8.9 hours
So, it will take approximately 8.9 hours to charge the 12V deep-cycle battery with a 135-watt solar panel under the specified conditions.
However, it's important to note that these calculations provide an estimate, and the actual charging time may vary based on real-world conditions such as shading, temperature fluctuations, and panel orientation. Additionally, charging a battery beyond its recommended voltage can damage the battery, so it's essential to use a proper charge controller to regulate the charging process and prevent overcharging.
