Battery Equivalents and Replacements

Generator vs. Inverter: What is an Inverter Generator?

Regular generators and inverter generators are very similar devices that convert the chemical energy of the fossil fuel into mechanical energy (rotation of the internal combustion engine) and mechanical energy into electric energy (electric generator).

However, although their operation is very similar, internally, there are several very important differences...

Updated: March 11, 2024.

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Inverter Generator vs. Regular Generator

The main difference between inverter generators and regular generators is that in order to keep the AC output voltage frequency more or less constant, regular generators must spin their internal combustion engines at a constant speed all the time.

For example, in order to achieve 50Hz output, internal combustion engines spin at 3000 RPM, and to achieve 60Hz output, internal combustion engines spin at 3600 RPM.

The output voltage is a form of the sine wave but has plenty of harmonic distortions, sometimes with more than 20% THD, which can cause issues when powering sensitive electronic and electric devices.

Also, since the engine spins rather fast even when there is no load present, regular generators are less efficient, create a lot of noise, require more maintenance, and don't last as long as inverter generators.

honda eu2200i 1

On the other hand, inverter power generators feature built-in electronics that 'store' the electric energy in the capacitors and using electronic converters (also known as "inverters") generate electricity of required voltage, frequency, and waveform.

Note: this is a very simplified description of the inverter technology commonly found in inverter power generators!

This allows the engine to spin at the optimum speed, increasing fuel efficiency, decreasing the noise, increasing the engine lifetime, simplifying the maintenance, and similar.

Also, the amount of Total Harmonic Distortions (THD) in inverter generators is very often <3% at nominal power, allowing these units to directly power-sensitive devices like laptops, TVs, multimedia units, and similar.

Regular Generator or Inverter Generator: Which One to Choose?

For most residential and commercial applications, inverter generators are recommended choice - actually, for units up to 5 kW of output power, it is rather hard to find power generators that are not based on inverter technology.

Some of the most popular, rather quiet inverter generators are given in the following comparison chart:

Model

Running Watts

Starting Watts

Runtime Noise

Receptacle

Review

A-iPower SUA2300i 1800W
2300W
6.5h @50% 52 dB @25%
58 dB @50%
AC: 120V 20A 5-20R, 120V 30A L5-30R; DC: 12V 8.3A, USB 5V
-
Champion 2000W Model #100402 2000/1800W
1600/1440W
11h @25% 53 dB @25% AC: 20A 120V 5-20R Duplex; DC: 12V 8A
-
Champion 2000W Model #100692 1700W
2000W
11.5h @25% 53 dB @25% AC: 20A 120V 5-20R Duplex; DC: 12V
-
Energizer eZV2000P 1600W
2000W
11h @25% 50 dB @25%
56 dB @75%
60 dB @100%
AC: 20A 120V 5-20R Duplex; DC: 12V 5A
-
Generac iQ3500 3000W
3500W
8.9h @50%
14.1 @25%
45* dB AC: 120V 20A Duplex 5-20R, 120V 30A L5-30R; DC: two USB ports (5V/2.1A, 5V/1A)
Review
Honda EU2000i 1600W
2000W
8h @25% 50 dB @25%

AC: 20A 120V Duplex; DC: 12V
-

Honda EU2200i 1800W
2200W
3.2h @100%
8.1h @25%
48 dB @25%
57 dB @100%

AC: 20A 120V Duplex; DC: 12V 100W (8.3 Amps)
Review

Honda EU3000IS 2800W
3000W
20h @25% 50 dB @25%

AC: 120V 20A Duplex, 120V 30A L5-30R
-

WEN 56203i 1700W
2000W
10.8h @25%
7h @25%
51 dB @25% AC: 2x NEMA 5-20R; DC: 12V (8.3A), 2x USB 5V (1A, 2.1A)
Review
WEN 56235i 1900W
2350W
10.5h @25% 51 dB @25% AC: 15A 120V NEMA 5-20R Duplex; DC: 12V, USB 5V (2.1A, 1A)
-
Westinghouse iGen2600 2200W
2600W
10h @25% 52 dB @25% AC: 20A 120V Duplex; DC: 12V, 2x USB 5V
Review
Westinghouse iGen2800c 2200W
2800W
12h @25% 52 dB @25% AC: 20A 120V Duplex; DC: 2x USB 5V
Review
Westinghouse iGen4500 3700W
4500W
18h @25% 52 dB @25% AC: 120V 20A 5-20R Duplex, 120V 30A TT-30R; 2x USB 5.0V (2.1, 1.0 A)
Review
Yamaha EF2000iSv2 1600W
2000W
10.5h @25% 51.5 dB @25% AC: 120V Duplex; DC: 12V 8A
-
Yamaha EF2400iSHC 2000W
2400W
8.6h @25% 53 dB @25% AC: 120V Duplex; DC: 12V 8A
-

Note: Amazon affiliate links ('Model' Column) open in the new windows, feel free to check them for the most up-to-date offers and prices.

Of course, there are many more inverter generators on the market, but these units are exceptionally quiet considering their output power, making them the preferred choice for residential use, camping, tailgating, and other off-the-grid applications, and, of course, in emergencies.

Note: Power generators, both regular and inverter generators, MUST be kept outside, down the wind, during operation - they produce fumes that contain carbon monoxide (CO) which is very dangerous to humans and animals. For exact safety procedures, please, check the Owner's Guide of the generator that You have.

Do inverter generators have batteries?

Some inverter generators do have small, usually motorcycle-style, starting batteries, allowing them to be started with just a press of the button.

Also, in advanced models, such batteries power onboard electronics while the engine is turned Off - such onboard electronics may support features like remote start, WiFi/Bluetooth connectivity, etc.

When the engine is started, the onboard battery is recharged automatically.

To help with the maintenance, some inverter generators with onboard battery are delivered with battery charger, allowing the users to recharge the battery periodically while the power generator is stored without starting the engine.


Just to clarify a few things, here are a few additional notes:

Power Inverter vs. (Power) Inverter Generator

giandel ps 1200jcr inverter 1Power inverters are electronic devices that convert electric energy, usually from the deep cycle batteries, of one form (usually 12V, 24V, 36V, 48V DC) into electric energy of another form, usually AC electricity - 120V, 220V, single-phase, three-phase, and similar.

Very often, power inverters have USB ports for direct charging of smartphones, tablets, and similar devices.

Also, power inverters during operation don't emit any fumes and can be used indoors, unlike power inverter generators.

Can a power inverter replace a power generator?

An average 3000W power generator can operate 7-9 hours on one full tank of fuel @25% load - that is ~750W.

For a 95% energy efficient power inverter to operate, let's say, 8 hours, it takes:

P(W) = 750W / 0.95 = ~790W

If the power inverter is a 12V unit, then its current is (Ohm's Law):

I(A) = 790W / 12V = 65.8 Amps

And for the 12V battery pack to provide 65.8A for 8 hours, one needs the battery pack of at least:

Capacity = 65.8A * 8h = 526.4 Ah

So, if you wonder if a power inverter can replace a power generator, the answer is yes, if you have a large enough battery. Also, when the fuel tank of the power generator is empty, it can be refilled within seconds, while the battery takes anywhere from 1-2 hours (lithium battery) to 6-8 hours (lead-acid battery) to be fully recharged.

For more information about these units, feel free to check out the Power Inverters page.

Power Station vs. Power (Inverter) Generator

jackery explorer 1000 w300Power stations are devices that combine built-in deep cycle, usually lithium batteries and power inverters in single units.

As such, they can be used both indoors and outdoors since they don't emit any fumes.

Also, they are very quiet during the operation.

However, the operating time of the power stations is limited by the amount of energy stored in the local battery.

For more information about these units, feel free to check out the Best Portable Power Stations page.

Fuel Cell vs. Power (Inverter) Generator

hydrogen fuel cells 2

A fuel cell is an electrochemical device that converts the chemical energy of hydrogen into electricity through a pair of redox reactions.

Unlike batteries, fuel cells require a continuous source of fuel and oxygen to sustain the chemical reaction.

In essence, fuel cells can be considered as devices "between" the batteries and power (inverter) generators - fuel cells "burn" hydrogen using oxygen from the air and produce electricity and water as a byproduct.

Fuel cells are much more efficient than internal combustion engines, with efficiency in the 50-60% range, which is better than the efficiency of large diesel engines that go up to 40-50%.

Also, to increase the efficiency of the fuel cells, thermal energy can be captured and used for other purposes, the efficiency of fuel cells can rise to 80-90%.

For more information about this topic, feel free to check out our Guide to Hydrogen Fuel Cells article.

Just for comparison, when the lead-acid battery is discharged in one hour, its efficiency is in the 50-60% range, with lithium batteries featuring efficiency in the 80-90% range, with newer models having efficiency >90%.

Note: the efficiency of the batteries, especially lead-acid batteries, depends on the drain current, temperature, and similar.

The fuel efficiency of the power generators depends on the engine type (two or four strokes), fuel type (gas/propane/natural gas/diesel), and generator load and can be anywhere from 10-15% to ~30%.

Large diesel generators can operate at 35-45% efficiency, but those are large industrial units with turbochargers, intercoolers, and similar features that increase the complexity of the power generator but also increase the efficiency of the unit.


Long Story Short: the main difference between regular power generators and inverter power generators is the output controller (inverter) found in inverter power generators, allowing them to be more fuel-efficient, to require less maintenance, generate less noise, and to have output power with less THDs, often under 3%.

Inverter generators initially cost more than regular generators, but they compensate for the price difference rather quickly.

Again, never, but really never operate any power generator indoors...