The right solar array size depends on your battery’s total energy capacity, how much energy you use each day, how quickly you want to recharge, available sunlight, and the specifications of your solar charge controller.
A good starting point is to calculate your battery’s approximate stored energy:
Battery Voltage (V) × Capacity (Ah) = Watt-Hours (Wh)
From there, consider how much of that energy you need to replace each day, the number of peak-sun hours available, and your desired recharge time when sizing your solar array.
A larger solar array can provide more charging power, but the array’s voltage, current, and total wattage must remain within the limits of your solar charge controller and battery system. Actual charging performance will also vary based on sunlight, weather, panel orientation, temperature, and system efficiency.