power inverter

What Will a 400 Watt Power Inverter Run? Guide and FAQ

A 400-watt inverter is a device that converts DC current from a battery or power source into AC power for use in the home.

Units with this type of rating are often used to run appliances such as refrigerators and stoves, as well as to power air conditioning units and other types of electronics. A unit with a 400-watt rating can be found online for sale in most instances, and it’s recommended that you purchase an inverter with more than 300 watts, so you don’t have to worry about the risk of overloading your equipment and breaking down due to heat spikes or voltage surges. 

A  400-watt inverter is often used in conjunction with other power products to create up to 1,000 watts of total output. Inverters are typically sold as ‘multi-output,’ meaning the user can adjust them to produce a different amount of electricity depending on their needs. 200, 300, and 400-watt units are most common and always deliver the same output despite their ratings. 

Appliances a 400 Watt Power Inverter Will Run

Here’s a list of some of the appliances which a 400 watt power inverter can run!


In recent years, the popularity of laptops and other computers has exploded. It seems as though just about everyone is purchasing laptops instead of desktop computers or desktops. Their portability makes them useful in many different situations. Many inverters will have 400W of output power and will be able to run up to five laptops (50 watt example) at once without a problem. This is why they are used in many offices and schools. Even in homes, people will use them to turn off the lights when they aren’t using them and to keep things from being too bright at night. Three of these inverters will be able to provide enough power for eight laptops if you use the right wiring setup. If you do not have enough outlets in your home, then this is a great way to solve that problem as well because these inverters can be used with most major brands of laptops on the market today.


Blenders are typically powered via an AC power outlet. However, a 400-watt inverter can be connected to a car battery to operate the blender. Inverters fluctuate power based on demand at that time, so when you turn on a blender and set it to high, the motor will begin to run as soon as there’s enough power. This is because inverters prioritize items that are plugged into them in order of importance (starting with things used most often).

Residential fan 

If your household fan is not running on a 240-volt circuit and you want to run it by a 400-watt inverter, you have to use a 3-speed, 120 volt AC household fan (sometimes called an “alto”). A 400-watt inverter can’t produce enough power to operate the slower speeds of 3-speed 120 vAC fans.

However, if you want to use the same speed as your 240 v appliance operates, there’s no problem. The 400-watt inverter will produce enough power to operate the appliance at its full speed. Of course, if your fan is a more powerful model that requires 500 watts of power to run, the 400-watt inverter will not be able to run it.


Many people know that if you’re looking to get your TV working with electricity instead of solar without paying for a professional, one of the prime options is a 400-watt inverter. However, many people aren’t aware of the challenges this might pose for your viewing experience.

To understand these challenges and how you can overcome them, you need to understand how these low-power outlets work. Essentially, when the outlet is used appropriately and not overloaded, it will provide an adequate amount of charge for small electronics like those connected in a typical home environment.

Processors and Mixers for Kitchen

There are several inverter-friendly mixers today, and there is no reason you should not buy one for your kitchen. Of course, there are some suggestions that you may have to follow for your mixer to work properly. You’ll need to get an inverter with at least 400W output power and an acceptable speed range (around 10,000 RPM) motor.

Number of Batteries That I Need To Run A 400W Inverter?

Batteries are often overlooked when it comes to powering a mobile off-grid system. Many people assume that they will run their system indefinitely on solar or wind power, but this is not the case. Let us explore how many batteries you need to run an inverter with a 400W load at 12V voltage. Let’s start with the following formula: 2xNxPxV=W, where N is the number of cells in your battery; P is the terminal voltage in volts, and V is the battery’s watt-hour capacity (voltage times capacity).

This formula calculates how many batteries you need to run a 400W inverter for one hour at 12V. 2x6x12=96 watts, which means you need 96Wh (or 96,000Wh) of power from your battery. You can use a lower power load if you plan to run the system for a longer period. For instance, if you expect to run the inverter at its 400W load for 8 hours every day and you still want it to last one year, then W=400x8x365=436,800Wh (you will need 437Wh/day). These calculations assume you will keep the battery charged and in good condition.

In our example, we calculated the power to run 400W for 12 hours (1 hour at a time) at 12V, which is exactly what you need to run a 400W inverter for one hour. However, suppose your inverter supports lower load levels. In that case, you can use this formula to calculate how many batteries you need to run it for 12 hours at its lower voltage level (12V x 0.7V=96W, which means you need 96Wh of power from your battery).

 A battery’s watt-hour capacity is usually specified in a 10h or 20h rating, which means the number of hours it can supply a load at 20A or 10A, respectively. As you can see above, you need 96Wh to run a 400W inverter for 12 hours. So let’s calculate how many batteries you need to run the inverter for 12 hours at a lower load level (96/2=48Wh).


One of the biggest concerns when you’re looking to outfit your home with solar panels, is the inefficiencies of conventional inverters. However, there is now a reliable rating system that helps measure how well an inverter can use its power output for various tasks. The concept of an inverter rating was put forth by the US Dept. of Energy to help consumers be able to find the best types of inverters for any circumstance, including for powering a household on solar power and even off-grid applications. While wattage tells you how much Energy a system can produce, the efficiency rating is more helpful when determining the best system for your situation.

Frequently Asked Questions

What can I run with a 400 watt inverter?

You can run most small to mid-sized appliances with a 400 watt power inverter paired with a reliable power source.

What size wire do I need for a 400 watt inverter?

A 400 watt inverter is best paired with an 8 inch cable if your wiring distance is under 3 feet.

This depends on how much power you are drawing consistently and the size of the battery. We have an article on this here.