To determine the how many watts of solar panels are needed to charge a 150AH battery, you need to consider some factors like the battery's voltage, the available amount of sunlight in your area, and the charging time. Here's a basic formula to estimate that:

Wattage (W) = Voltage (V) x Ampere-Hours (AH) / Charging Time (in hours) x Solar Panel Efficiency

1. Voltage (V): Check the voltage of your 150AH battery. It's typically 12V for lead-acid batteries, but it can vary.

2. Ampere-Hours (AH): You mentioned the battery is 150AH, so use this value.

3. Charging Time (in hours): Determine how long you want to charge the battery. Let's assume it's 6 hours for a moderate charge.

4. Solar Panel Efficiency: Solar panels are not 100% efficient. A typical efficiency is around 15-20%. You can use 0.15 or 0.20 as a decimal in the formula.

Now, let's calculate the wattage:

Wattage (W) = Voltage (V) x Ampere-Hours (AH) / Charging Time (in hours) x Solar Panel Efficiency

Assuming a 12V battery, a 150AH capacity, a 6-hour charging time, and 15% efficiency:

W = 12V x 150AH / 6 hours x 0.15 = 450W

So, you would need approximately 450 watts of solar panels to charge a 150AH battery in about 6 hours with 15% efficiency. Keep in mind that these are simplified calculations, and real-world conditions can affect the actual wattage required, such as weather conditions and the angle of the panels. It's always a good idea to consult with a solar expert for a more accurate assessment based on your specific needs and location.