What is an inverter and how to choose one?

What is an inverter?:

At its most basic principle, a power inverter is simply a device which converts a single voltage polarity direct current, DC, electrical charge into an alternating current, AC, electrical charge. The reason for doing this is because most of the electronic devices we use in our everyday life run on AC electricity. However, there are many situations when you may not be able to access an AC outlet supplied by a standard power grid.

Xantrex PROsine. CREDIT: Xantrex

If you are camping, on a boat, or simply on the road, chances are you will only have access to a DC battery. This also generally applies to most off-grid solar arrays. These are situations where a power inverter can ensure that the DC power you have available is made usable for your various electronic devices.

What types of power inverters exist?:

In terms of strictly inverting DC electricity into more widely usable AC electricity, there are two main types of power inverters: pure sine wave and modified sine wave. However, even within the different types of sine wave power inverters, there can be different features that offer even more versatility.

AIMS Inverter Charger. CREDIT: AIMS

For instance, some company manufacture power inverters that can also double as battery chargers. This is a bit like a two-for-one package since the inverter charger can charge your battery then turn right around and invert the power it just supplied to make it usable for your numerous electronic devices. You can find a few examples in our AIMS power inverter reviews

Beyond additional functions, some power inverters are made with unique characteristics that are suited for particular circumstances. For instance, a quick look at the Best Power Inverter Brands will show that different brands are better equipped to handle different environments or different types of equipment.

What is the difference between pure sine and modified sine wave inverter?:

The primary difference between the best modified sine wave and the best pure sine wave inverters involves how the they alter the voltage polarity of the DC electrical charge. The difference between these two carries significant implications in regards to which electronic devices are appropriate for which type of power inverter. In pure sine inverters, the output voltage waveform is smooth and produces a current virtually identical to utility power, with very little harmonic distortion. In modified sine wave inverters the output voltage wave is a form of square wave and it has a large amount of power efficiency loss due to significant harmonic frequencies.


The best 3000 watt pure sine inverters and modified sine inverters may offer the same wattage capacity, but that does not mean you should run the same electronics on both. Though, it is the modified sine wave inverter which comes with limitations. Basically, pure sine wave inverters use more complex and refined components to ensure that the alternating voltage polarity remains smooth throughout its inversion process.

Samlex Modified Sine Inverter. CREDIT: Samlex

Modified sine wave inverters, on the other hand, generally shift the polarity in much sharper steps creating what is known as a “square sine wave.” This sudden shift in voltage polarity can negatively impact some electronic devices with microprocessors or other sensitive components, and those devices may not work effectively.

Which one is the best?:

This is a bit more tricky to answer in any definitive way. The qualities that make up the best power inverters for cars are not the same qualities that will define the best power inverter for trucks

Ultimately, you need to figure out where you intend to use this device, what type of electronics you intend to power with it, and the total wattage of the electronics you intend to power. That said, the difference between modified and true sine wave inverters is fairly easy to answer.

Pure sine wave inverters are more efficient, produce less heat, are compatible with all types of electronic devices, and are generally longer lasting than modified sine. In fact, the only reason you might choose a modified sine wave inverter of a pure sine is the price. Modified sine wave inverters are generally significantly less expensive than pure sine.

What is inverter generator?:

It is essentially the opposite of a power inverter. Where a power inverter takes a DC electrical charge and inverts it into an AC electrical charge, an inverter generator creates an AC electrical charge and stabilizes the voltage polarity into a DC electrical charge. Then the DC electrical charge is converted back to an AC electrical charge.

If this seems unnecessarily complicated, there is a good reason for this process. Essentially, the original AC electrical charge created by the generator is often at such a high voltage that it could potentially damage electronic devices powered by it. To prevent that issue, the initial AC electrical current is stabilized to a DC electrical current that carries a lower voltage.

This DC electrical current with the lower voltage is then inverted back into an AC electrical current that is safe for your electronic devices to use. The main benefit of this product is that it can generate the electricity from a combustion fuel source without the need of other electric hardware to provide power.

What size of power inverter do I need?:

Bestek 2000w. CREDIT: Bestek

This question will depend on what you intend to use it for. If all you plan to do is charge a laptop or smart device but not actually run the device from the power inverter, a 150W to 300W inverter will probably do fine–it can even be a modified sine wave if all you do is use it to charge the devices.

However, if you plan on running a microwave, small refrigerator, or some other device that will likely require over 1000W, you will want to ensure that the power inverter can provide that wattage at a minimum–though it is often a good idea to get something with a wattage capacity a bit more than you intend to use.

For example, 2000 watt pure sine power inverters are a solid choice for large loads that demand a clean, pure source of AC power. They can run several appliances and still provide plenty of pure, clean power for the sensitive loads. More information you will find in our article 10 Best 2000 Watt Pure Sine Wave Inverters

What are the criteria is that one should consider when choosing an inverter?:

The first thing to figure out is whether you need a pure sine wave or whether you can get by with a modified sine wave power inverter. If you only need it to run fairly basic electronic devices without microprocessors and other sensitive components, there may be little point in spending the extra cash on a pure sine wave inverter.

After that, you need to figure out how much wattage you need. A power inverter used at a construction site will likely need to handle more total wattage than the one that is used at a campsite. Keep in mind, the peak surge wattage will be important as well, though this only matters when you first plug the device in.

Finally, where you plan to use the power inverter will affect which one is appropriate. Some are designed to be able to handle the hot, dusty conditions of the desert and are great for solar arrays in that environment. Other come with protection from water and are ideal for use on boats and other marine settings


by Paul Ertel January 11, 2018