Generators Inverter Generators

The Ultimate Champion 100302 4000-Watt Inverter Generator Review

Nothing beats a generator when it comes to powering your home during an emergency power outage or providing power for your RV, campsite, and other outdoor adventures. However, purchasing the right generator to meet your power needs can be an uphill task and becomes more intimidating when you have hundreds of options to consider.

We researched various generators that can meet the average household’s needs and looked at how they would power all your essentials like lights, TV, internet, refrigerator, sump pump, and many other appliances. Then, we shortlisted our picks and settled on the Champion 100302 4000-watt open frame inverter generator. Simply put, this generator can be defined as the ideal balance between power, features, reliability, and durability. It has everything you would need in a home backup and outdoor-use generator.

Moreover, it comes from a reliable brand. Champion is a well-known brand that has been in the market for quite some time and provides dependable alternative power solutions worldwide.

Before we explore the Champion brand and investigate Champion’s 4000-watt open frame inverter generator, it is pertinent that we understand what an open frame inverter is and how it is different from a simple (closed frame) inverter generator.

What is an Open Frame Inverter Generator?

When searching for a new generator, you’ll come across countless types of generators available on the market: portable, dual fuel, standby, closed-frame inverter, and open frame inverters. Unfortunately, it isn’t easy to navigate through the veritable sea of generators out there. Luckily for you, we are here to help you understand the open frame inverter and how it differs from a closed frame inverter generator. 


Open Frame Inverter vs. Closed Frame Inverters

  • Design: Open frame inverters have a more accessible design compared to closed frame inverters. It makes maintenance easy but removes the safeguards from elements like wind, dirt, and water.
  • Noise Levels: Open frame inverters are noisier than their closed counterparts. The reason is they don’t have sound-absorbing covers over the engine and have more moving parts than closed frame inverters.
  • Price Point: Open frame inverters are cost-effective against closed-frame machines. They are best for people on a tight budget that still want clean and low THD power for sensitive appliances like TV, laptops, phones, etc.

Champion Power Equipment Brand

Champion Power Equipment, commonly known as Champion in generator world, was founded in 2003 in Santa Fe Springs, California. Over the years, Champion expanded its North American footprint to include facilities in Jackson, Tennessee, Milwaukee, Wisconsin, and Toronto, Canada.

The yellow and black colored Champion generators are now well known for reliability, durability, and above all, affordability. Champion has powered millions of homes, offices, RVs, and commercial facilities with its vast product range and versatile generators. Apart from generators (portable, inverters, dual-fuel, and standby), Champion also produces log splitters, chipper shredders, cultivators & tillers, pressure washers, water pumps, snowblowers, and gardening tools. 

Aided with innovative technology, superior customer service, and US-based engineering, Champion has succeeded in selling 2.5 million generators in its 18-year journey and is gearing for more.

Learn more about the history of the Champion Power Equipment brand and get our list of their top 8 products here.

Let’s get down to real business now and review the Champion 100302 4000-Watt Open Frame Inverter Generator!

Review of the Champion 100302 4000-Watt Inverter Generator

Champion’s 100302 4000-watt inverter generator is one of the most sought-after and frequently purchased generators in its category. It offers the convenience of a conventional generator and the class of an inverter generator. In addition, with 100302, you get easy maintenance and low THD output.

Champion describes this model as 50% quieter and 20% lighter than a traditional generator with the same output. Moreover, it offers parallel connectivity, extended runtime, and economy mode.

Let’s check out its features compared to other generators in the same category and its customer reviews.

Power Output and Usability

The gasoline-powered machine produces 4000 starting and 3500 running watts. The power output is in line with other generators in its class. You can power lights, run your computer, TV, sump pump, and even a small AC on this generator. It is also best for running sensitive appliances because it produces power with a total harmonic distortion of 3% or less. This feature is impressive and sets the machine apart from its competitors.

The power output makes the machine ideal for small to medium RVs, fairs, festivals and other outdoor events, small worksites, people who have to run tools on the go, tailgates, and campgrounds. It is also best for homeowners looking to power their essentials during emergency-based outages. However, it lacks the dual-fuel option, which is an added benefit during outages.  

The starting amps for this machine are 33A, and running amps are 29.2A, whereas the output is 120 volts and frequency 60Hz.

Gas Tank Capacity and Runtime

The gas tank capacity is 2.9 gallons, and the machine offers a runtime of 17 hours at 25% load, as stated by Champion. At 50% load, the runtime is around 8 hours and 4 hours for a full load. Thus, the gas tank capacity and runtime are in perfect harmony. Let us break this down for you.

When the load applied on the inverter is 1750 watts, your machine will run for approximately 8 hours. Unfortunately, we can’t provide fixed runtime because runtime depends on a few factors such as your generator’s age and engine performance, appliances’ age, wires affectivity, and gas quality. In practical situations, the runtime can differ by 30-60 minutes than the stated runtime.

However, to get the best runtime, you must add one appliance at a time and turn off the appliances you don’t need anymore. We aren’t talking about refrigerators; fixtures such as lights, chargers, sump pumps, water heaters, well pumps must be turned off quickly once their work is done. Moreover, the Champion 4000-watt inverter comes with an eco-mode that adjusts the engine speed according to the load applied. It results in two benefits; first, it gives better fuel economy and extended runtime. Secondly, it keeps your generator quieter when running at a low load.

Engine Specifications

The machine uses a 224cc 4-stroke Champion engine with variable speed. The engine is powerful enough to supply a steady flow of 3500 watts, and you will never feel that your machine is underpowering your appliances. Of course, if the carburetor and fuel pipes are not working correctly, you may face some issues, but with a mint condition engine, your machine will always be up and running with 1-2 pulls of the starting rope.

The gas tank on the engine is made of steel. The manufacturer recommends putting fresh gas all the time and keeping the carburetor empty when you plan on storing the machine for a long time. The recommended engine oil type is 10W-30. You will need to buy engine oil (0.6 quartz) separately as it is not included in the original purchase.

Champion’s 100302 comes with an eco-mode that reduces the engine speed as per the load on it and results in higher engine life, quieter operation, and higher fuel economy.

Control Panel and Outlets

The control panel on this machine is too outdated and straightforward for many people’s liking. It lacks a voltmeter or a data center, forcing users to keep a manual record of running hours for maintenance and oil change. However, the control panel offers LED indicators for output, low oil, and overloading.

The generator comes with an on/off button (not electric/push start) for controlling the current flow, an eco-mode button, parallel connectivity port, breakers, and outlets.

The outlets consist of one 120V 30A (TT-30R) outlet, one 120V 20A duplex (5-20R) outlet, and one 12V DC automotive outlet. Please note that these outlets are not GFCI protected and are not rubber covered. Moreover, the circuit breakers are not covered; therefore, you will have to take extra care to keep the outlets free from dust and debris.  

Noise Level

The stated noise level is 64.0 dBA at 23 feet. The noise level is higher than closed frame inverters but lower than traditional generators in the same range. One effective way to reduce the sound level is to use a muffler or build a generator enclosure with ample exhaust and heat exchange space.

Dimensions and Weight

The unit measures 20.5 x 17.9 x 17.7 inches and weighs 81.6 pounds. The dimensions and weight are almost the same as other generators with 3500-watt output.   


Portability is a crucial feature for open-frame inverters and other generators in this power range. Unfortunately, this model doesn’t come with wheels and a handle kit. This creates a big question mark about this machine and leaves users pondering whether to buy this machine or select a more portable option.

However, considering the wheel kit and generator’s price, it is still cheaper than machines that come with wheel kits. Champion’s 4000-watt inverter’s wheel kit is easy to install, and you can read more about it here and find installation details in the manual.      

Warranty and Certifications

Champion’s 100302 inverter generator is covered with a 3-year limited warranty for residential use 2 years for commercial and industrial use. The warranty agreement covers defects in material and workmanship for mechanical and electrical components. The warranty is not applicable when normal use has exhausted the life of a part of the whole machine. Therefore, you must regularly maintain your machine and take care of its parts. The warranty also excludes cosmetic defects such as paints and decals. Furthermore, it stands void due to the installation of non-Champion parts and against acts of God. Please note that transportation charges on products submitted for warranty claims are the sole responsibility of the purchaser.

The Champion 100302 is EPA-approved and CARB-complaint. Its sale and purchase are legal in all 50 states. EPA recommends keeping the generator at a safe distance of 15 feet to limit exposure to sound and emissions. It is essential to highlight that the machine is not PGMA G300-2018 Compliant.  

Additional Features

  • Cold-start Technology: 100302 comes with a cold-start technology that enables buyers to start the machine quickly when the temperature drops below the freezing point.
  • Economy Mode: The machine comes with an eco-mode that adjusts the RPM according to the load applied, resulting in longer runtime and engine life.
  • RV-enabled Outlets: The 120V 30A (TT-30R) outlet is RV-ready. It functions like just plug-and-play for your RV.
  • Parallel Connectivity: Parallel connectivity allows you to connect your machine with another Champion hybrid unit or a compatible Champion inverter to double up the power.
  • Included Parts: You get an oil funnel, battery charging cables, and a USB adapter. Please note that battery, oil for first-time use, and wheel kit are not included in the purchase.     
  • Lifetime Support: The unit comes with free lifetime technical support from Champion Power Equipment.


The open-frame inverter is on the average price side, as you will see in the comparison section below. Hence, it suits the pockets of budget buyers people looking for a generator that does what it’s supposed to do: provide backup power without any tantrums.

User Reviews

The overall rating for this machine is on the good side. A majority of the buyers (more than 90%) rate this machine with 4-5 stars. Buyers like the machine due to its reliability and dependability during the time of need. They say that the machine starts quickly without making any fuss and runs smoothly. They rate it best for appliances like sine-wave UPSs that are very sensitive to power fluctuations and voltage drops.   

Another thing commonly praised by buyers is the durability and sturdiness of the machine. The frame is well-built with powder-coated steel and every part installed on the unit looks good. Setting up the machine and installing the wheel kit (not included) is also easy and you can be up and running in a couple of hours.

A lot of buyers like shipping and customer service as well. There have been no significant incidents of receiving defective products or damaged units. If any customer has faced such an issue, Champion has gone the extra mile to help them out.

The common complaints are a noisy machine. Buyers are also frustrated about the non-included parts like battery and oil. Many buyers wish to have a data center in this machine.   

Champion 100302 Open Frame Inverter Generator


Champion 100302 Open Frame Inverter Generator vs. Competitors

The major competitors to this model are Westinghouse Wgen3600v, DuroStar DS4000s, Champion’s 200986 4500-watt inverters, and WEN GN400i 4000-watt open inverter generator.

  • WEN GN400i is compact and lightweight than Champion 100302 and weighs only 66 pounds. It is also cheaper than Champion, but it is slightly noisier than 100302. All the other features are somewhat similar. Not to mention, it made our list for Best Bang For Your Buck – Picking A Small Generator At The Best Price.
  • Compared to Westinghouse’s Wgen3600v, Champion’s 4000-watt open frame inverter is costly but slightly underpowered. Wgen3600v delivers 4650 starting and 3600 running watts compared to 4000 starting and 3500 running watts produced by Champion’s machine. However, Wgen3600v is bulkier and doesn’t offer low THD. So, it is not safe for sensitive appliances. Moreover, it is a conventional generator.
  • DuroStar’s DS4000s is also inexpensive compared to Champion’s 100302, but it is noisy and unsafe for sensitive appliances. We also found it among the 5 Best Value Generators For Your Home.
  • Champion’s 200986 4500-watt closed frame inverter offers 4500 running and 3500 running watts. It is more costly than the 100302 4000-watt open frame inverter but is less noisy. It also comes with wheels and a retractable handle, making portability as easy as you like. However, it is heavier than the 4000-watts inverter generator.

Champion 100302 4000-Watt Inverter Generator


  • Affordable
  • Lightweight than other machines
  • RV ready
  • Parallel capable
  • Easy to maintain and use
  • Impressive fuel efficiency
  • Decent runtime
  • Lifetime technical support


  • Battery and oil not included
  • Noisy
  • No data center
  • Lacks electric start option
Champion 100302 4000-Watt Inverter Generator
  • Advanced Open Frame Inverter Design: 50% quieter and 20% lighter than a traditional Champion 3500-watt generator, plus our Economy Mode feature saves fuel and extends engine life
  • Quiet Technology and Extended Run Time: 64 dBA is great for RVs, tailgating, your next project or home backup, with 4000 starting watts and 3500 running watts for up to 17 hours run time on gasoline
  • Clean electricity for sensitive electronics: RV Ready with a 120V 30A RV, plus two 120V 20A household outlets with clean power (less than 3% THD) and 12V DC outlet with dual USB adapter
  • Parallel Ready: Increase your power output by connecting up to two 2800-watt or higher inverter or digital hybrid with the optional Parallel Kit
  • Champion Support: Includes 3-year limited warranty with FREE lifetime technical support from dedicated experts

Champion 100302 4000-Watt Inverter Generator Documentation:


Are Champion generators worth buying?

Yes. Champion generators have one of the best ratings on almost all the platforms and review sites. As a result, buyers frequently recommend Champion products. Moreover, they are affordable, have a decent warranty, and offer great features.

What will a Champion 4000-watt generator run?

The rule is simple; anything with a starting wattage below 4000 watts and running wattage below 3000 watts can be powered on a 4000-watt generator. However, you can run your essentials like lights, TV, internet, laptops, phones, sump pumps, refrigerators, and well pumps. You can also connect your RVs.

How many hours is a Champion generator good for?

A Champion generator can last between 1000 and 2000 hours. So if you run your generator for an average of 100 hours per year, it can last for 10-20 years.

Are Champion Generators made in the USA?

Champion has 4 production facilities in North America. Its machines are made in the USA and also imported.