To determine what size solar panel is needed to charge a 12V battery, there are a few factors to consider, including the battery capacity, expected discharge rate, and energy consumption. Here are the general steps to follow:
- Determine the battery capacity in amp hours (Ah) or watt hours (Wh).
- Calculate the expected discharge rate in Wh per day.
- Divide the discharge rate by the battery voltage to get the required Ah per day.
- Multiply the required Ah per day by the number of hours of sunlight available to get the required charging current in amps.
- Divide the required charging current by the voltage of the solar panel to get the required panel size in watts.
For example, if you have a 100 Ah 12V battery and expect to discharge it by 50% each day (i.e., 600 Wh per day), you would need a solar panel that can provide at least 50 Ah per day (i.e., 6.25 A for 8 hours of sunlight). To calculate the required panel size in watts, you would divide 50 A by 12 V to get 4.17 W. However, its important to note that this is just a rough estimate, and the actual panel size needed may vary depending on factors such as weather conditions and the efficiency of the solar panel.
