How to Run a 750W Load for 4 Hours per Day with a 12V Inverter and 150Ah Battery

Running a 750-watt load for 4 hours per day can be achieved with a 12V inverter and a 150Ah battery, but it requires careful planning to determine the necessary solar panel capacity. Here’s a detailed guide on how to calculate the required resources and optimize your setup.

Step-by-Step Guide to Determine Solar Panel Requirements

1. Calculate Daily Energy Consumption

First, calculate the total energy required for the load:

Daily Energy Wh Power W × Time h 750 W × 4 h 3000 Wh

2. Determine Battery Capacity

Next, consider the battery capacity. A 150Ah battery at 12V has a total energy capacity of:

Battery Capacity Wh Voltage V × Capacity Ah 12 V × 150 Ah 1800 Wh

Since you need 3000Wh per day, the battery alone is insufficient as it can only provide 1800Wh. To run the load for 4 hours, you would need to either increase the battery capacity or supplement it with solar panels.

3. Solar Panel Requirements

Now calculate how much energy you need to generate with solar panels to cover the deficit:

Energy Needed from Solar Wh Daily Energy - Battery Capacity 3000 Wh - 1800 Wh 1200 Wh

Assuming you have around 5 hours of effective sunlight per day, you can calculate the required solar panel output:

Solar Panel Output W Energy Needed from Solar Wh / Sunlight Hours h 1200 Wh / 5 h 240 W

4. Total Solar Panel Capacity

To ensure efficiency and account for losses in inverter efficiency, battery charging efficiency, and other factors, it's wise to oversize your solar panel system. A common recommendation is to increase the capacity by about 20-25%. Therefore, you might want to consider:

Total Solar Panel Capacity 240 W × 1.25 300 W

Conclusion

To run a 750-watt load for 4 hours per day using a 12V inverter and a 150Ah battery, you should:

Use a battery bank with a higher capacity Consider adding more batteries or Combine your existing battery with at least 300W of solar panels

to ensure you can meet your energy needs.

Additional Considerations

Inverter Efficiency

Factor in the inverter's efficiency, typically around 85-90%. If your inverter is 90% efficient, you should account for that in your calculations.

Adjusted Daily Energy 3000 Wh / 0.90 3333 Wh

Battery Depth of Discharge (DoD)

Avoid fully discharging your battery. Keeping it at a 50% DoD is common for lead-acid batteries to prolong their life.

By considering these factors, you can design a solar power system that effectively meets your needs.

Related Services

To ensure a tailored solution for your needs, Ayka Solar in Sydney can help you find the right solar panel setup. Connect with us today to get started!