We’re in the middle of a winter storm season and that signals the possibility of prolonged power outages. I can’t imagine surviving for a single day without heating or a functioning fridge. So I decided to take a look at some affordable medium-sized portable generators. I found out that between 3500 to 4000 watts is the sweet spot if you want a nice balance between weight and power. This is more than enough power to run your fridge, lights, TV, water heater, electric hob, etc. And you can even use one of these 4000W generators to power a 15k BTU air conditioner in your camper/ RV.
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While doing my research, I found out that a lot of people are interested in the Champion 100573. This is a 4000W open frame inverter, i.e. “digital hybrid”. Basically, it has all the benefits of a traditional open-frame generator (like what you’d find on a jobsite) – low cost, ease of maintenance, lots of power. Without any of the negatives like high levels of noise and decreased fuel efficiency. Don’t get me wrong, this is still a noisy machine. It isn’t something you can run all day in a campground. However, it is much quieter than a regular open frame generator. Quiet enough to run in bursts of 1 or 2 hours without causing any noise complaints from your fellow campers. Besides, you can comfortably use one of these at home to run essential appliances overnight if your area has been hit by a storm and you won’t have power for a while.
Champion also makes another 4000W open-frame inverter generator that’s significantly cheaper than the 100573. The model 100302 has the exact same 3500 running watts and 4000 starting watts as its more expensive cousin, but lacks certain quality of life features. I feel these added features on the 100573 are worth the additional money unless you’re on a really tight budget.
No matter which Champion you purchase, it beats owning a cheaply designed generator from cheap brands which might break down on you when you need it the most. Champion is renowned for delivering quality products at reasonable prices, plus their customer support is stellar. Each generator comes with a sticker on the back that has a phone number you can call, and your call will be received by an actual person. Champion also offers plenty of accessories in the box, and a 3-year warranty on all of their generators. You can’t place a price on stuff like this, the added peace of mind is enough to justify paying for a Champion product over some no-name Chinese generator.
Review : Champion 100573
Best 4000W Open-Frame Generator
- Advanced Open Frame Inverter Design: 50% quieter and 20% lighter than a traditional Champion 3500-watt generator, plus this inverter only produces Clean Power, and Economy Mode saves fuel
- Outlets : RV Ready inverter — 1x 120V 30A RV (TT-30R) / 2x 120V 20A household outlets (5-20R) / 1x 12V DC automotive-style outlet / 2x USB adapter and battery-charging cables.
- Wireless Remote Start: The wireless remote key fob allows you to start and stop your inverter from up to 80 feet away, plus the electric push-button start includes a battery
- 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
- Parallel Ready: The optional Parallel Kit (Amazon.com) allows you to increase your power output even more by connecting up to two 2800-watt or higher inverters or digital hybrids
- Champion Support: Includes 3-year limited warranty with FREE lifetime technical support from dedicated experts
“The Champion 100573 blends practicality and convenience into one very portable package that anyone can operate. It is powerful enough to start and run a 15,000 BTU RV air conditioner, but can also be quiet when you need it to be. The Eco mode on this generator will cut down on fuel consumption and noise levels if you aren’t powering heavy loads. And its remote start function is something that all generators at this price point should have, it’s simply the most convenient way to start a generator.”
There are several things I absolutely love about this generator. Its pricing, remote start, the fact that it’s an open-frame model with inverter tech which allows Champion to sell it at very competitive prices. Most inverter generators don’t even get up to 4000 watts, and the ones that do cost way more than the Champion 100573. If I were to pick the top 3 reasons you should buy this generator, they would be the following —
Clean Power (and plenty of it):
These days we rely on our laptops and phones to do a lot of our daily work. Pretty much everything is done on a computer – office work, filing taxes, listening to music, watching movies, playing games, etc. And when the power goes down, you rely on a generator to run your laptop or phone. But a conventional generator doesn’t produce “clean” energy. The AC current you get from a regular open-frame has Harmonic Distortion in excess of 20 percent. Harmonic Distortion is the amount of deviation present in the electrical power compared to an ideal sine wave. The power you get from a utility company at the wall is very close to a pure sine wave current. It’s ideal for operating delicate electronics with complicated circuitry and microchips.
But the power generated by a conventional generator isn’t smooth, it isn’t consistent. There are plenty of fluctuations in current which can cause electronics to overheat, and in worst case scenarios even fry the delicate circuits. An inverter takes this haphazard current, rectifies it into DC, and inverts it back into pure sine wave AC power which is clean and safe for phones/ computers. Total Harmonic Distortion must be under 5 percent to safely operate electronic gadgets and computers, and these THD values are only possible on an inverter generator. The Champion 100573 is one of the few inverter generators which offers 3500 running watts of clean power at under 1000 bucks. A competing model from Honda will cost way more.
I believe this is one of those features you don’t truly appreciate until you actually get to experience it. Imagine starting your 4000 watt generator powered by a 224cc engine, using the same amount of effort it takes to turn on a TV. Pretty awesome, right? Every mid-tier generator should have this feature. I know, it’s not commercially viable for companies to install batteries, starter motors, and wireless transceivers on every generator that costs 400 to 700 dollars. But Champion does it very well. There are 2 keys on the remote, one to turn on your generator and another to turn it off. Simplicity at its best.
One thing a lot of people will overlook is the remote shutdown. Yeah, being able to start your generator from inside the home or RV is cool. But you can also turn it off remotely. Imagine being at a campsite with a generator that pumps out around 68 decibels of noise. Clearly you can’t run this for extended periods, people will complain. So what you do, is use it in burst of 30 to 60 minutes to get the fridge cooled up or heat some food in your microwave. Then you switch it off. This entire process is made much simpler with a remote control since you can do it from the comfort of your couch instead of going outside twice every hour. Very convenient, especially if it’s raining or snowing.
A standard feature on every inverter generator, and one that is impossible to implement on a conventional generator. The alternator of an inverter is designed differently from that of a conventional generator. It doesn’t have to spin at a constant 3600rpm to generate 60Hz current. Which means the engine of an inverter generator can slow down or speed up, depending on the load. This allows for decreased noise levels and reduced fuel consumption. Think about all the times you don’t connect a heavy draw appliance to your generator. Maybe you just want to run a few LED lights and charge your phone. With the flip of a switch you can get the Champion 100573 into Eco Mode which significantly lowers noise and increases fuel efficiency. Not just that, but it also decreases mechanical wear and tear in the long term. The generator will automatically switch into full power mode if you connect a heavy draw appliance.
These are my top 3 reasons to purchase a Champion 100573. And remember, this is one of the highest value for money inverter generators you can purchase that isn’t junk. You get a nation wide support network and convenient parts replacement, not to mention a 3 year warranty. The open frame design does make it noisier than closed frame inverter generators. But it also allows Champion to keep the prices low. You trade off 4 to 5 decibels of additional noise for a cheaper generator. And if you’re a handyman with some DIY experience, you can easily rig up a plywood enclosure with some internal foam padding which will bring the noise levels down by almost half.
Open frame does have its advantages over closed frame in areas other than pricing. Maintenance for instance is much easier when everything from the muffler to the carburetor is exposed. You can easily drain the oil on this generator, and changing out the spark arrestor or air filter is a piece of cake. An open frame design also assists with cooling.
The Champion 100573 is capable of home backup, although I feel 4000 watts is not enough for a dedicated home backup unit. Around 6000 to 7000 watts is more like it. Still, 3500 running watts is plenty for mission critical stuff like CPAP machines. You can even power your computer, fridge, and 13.5k BTU air conditioner simultaneously in the RV/ camper. I also recommend the Champion 100573 for DIYers and jobsite use because it comes with a robust wheel system. These are hard plastic wheels instead of the foam filled “never flat” types you find on a lot of other generators. Hard plastic wheels don’t get those little dents in them like the foam filled never flats. Very handy on a jobsite with rough and uneven terrain. And there’s a folding handle on the front which makes transportation even easier.
You get a 30-amp RV outlet on the control panel, along with a parallel connection system so you can hook up two Champion 100573 generators together and run a 50 amp service in your RV. Champion includes battery charging cables in the package which you can power with the 12V automotive outlet. You can use this to jump start a vehicle or charge its battery. Running the generator will automatically charge its 2 volt 7Ah internal battery. And of course, you can start this generator by pulling a recoil starter rope. That comes in handy whenever the battery dies. Most people will use the push button electric start or remote start 99 percent of the time.
When you receive the generator, you’ll have to set it up. It’s very simple. You just need to attach the wheel kit (wheels and handle), and fill the generator with oil and gasoline. Then for the final step, you have to screw in the two battery cables. Champion provides a 12V USB adapter (with 2 ports) and 12V battery charging cables in the box.
Note: The Champion 100302 is basically a 100573 minus the wheel kit and electric starter. So you only get recoil start, and have to lift the generator if you want to transport it. It isn’t super heavy, since the removal of the wheel kit, battery, and electric starter bring the weight down from 97 to just 81 pounds. But still, lifting this is not something I would recommend for senior citizens or women. Plus, the 100302 has no flip-up covers for its outlets.
- Clean power thanks to inverter technology
- 4000 starting watts and 3500 running watts in a package that weighs just under 97lbs fully assembled
- Remote start/ shut down
- Eco mode which significantly lowers noise and fuel consumption if you don’t have power hungry appliances/ tools connected
- RV-ready with 30 amp twist lock outlet
- Parallel connection with another compatible Champion generator via parallel connection kit (purchased separately)
- Only 64 dBA of noise when measured at a distance of 23 feet (without any load connected, with a heavy load it’s closer to 68 or 70 decibels)
- 3-year warranty and free lifetime technical support
- All outlets have flip-up rubber covers to protect them from dust and moisture
- The relay for the remote start will drop out of standby mode after 12 hours of inactivity, so you have to walk up to the unit and reactivate it.
- I read reports of some customers who have a malfunction with the low oil sensor that causes the generator to auto shutoff after just a few minutes. This is very rare, and you should check oil levels to see if the sensor is malfunctioning.
Review : Powermate PM4500E
- One-touch electric start with auto-choke provides reliable, hassle-free startups.
- Large capacity steel fuel tank provides durability and up to a 20 hour run-time at 25% load.
- Powered by Generac 224cc OHV Engine provides consistent power for multiple applications.
- 8″ Never flat wheels for easy transportation. Hour meter tracks run-time and maintenance intervals. Low-oil level shutdown prevents engine damage.
- Fuel gauge allows users to keep track of gasoline levels. Covered outlets provide protection and keep out debris.
“An excellent choice for jobsites, home backup, and recreational purposes, the Powermate PM4500E delivers 4500 starting watts and 3600 running watts. It has one-touch electric start with auto choke which simplifies the startup process. The generator has a massive 5-gallon fuel tank that feeds a very efficient Generac 224cc OHV engine, resulting in runtimes of up to 20 hours (at ¼th load).”
Most of you reading this article probably never heard of Powermate before. But perhaps the name “Coleman Powermate” rings a bell for those among you who were shopping for generators a few decades ago. Coleman generators used to be a very popular brand, and their products were used everywhere from jobsites to campgrounds. But Coleman doesn’t make generators anymore. They sold their generator division called Powermate which declared bankruptcy in 2008. In 2009 Powermate was acquired by an Italian company called PRAMAC, which used significant sums of money along with dedicated management to revive this dying brand.
Today the Powermate brand is registered in Long Grove, Illinois. Powermate sources key components like the engine from some very reputable manufacturers. Think Honda, Generac, Subaru, etc. High quality components sources from across the world are put together in the US, and you should have no issue finding spare parts since every generator repair shop has Honda or Generac parts laying around. Plus, Powermate themselves have a robust support network and cover each generator with a 3-year residential warranty. They have everything from 1000W inverter generators to 9400W conventional generators. It is very easy to recognize a Powermate generator, just look out for the bold red color and aggressive styling (also… you know, the name POWERMATE in bold lettering).
The Powermate PM4500E is the electric start model of their conventional open-frame 4500W generator. There is another version called the PM4500 COsense which has a built-in carbon monoxide sensor (something every modern generator should be equipped with). Often, you’ll see “49ST” or “50ST” after the model name of a Powermate generator. That refers to the number of states where you can safely operate the generator while complying with state-specific emissions laws. Some Powermate models are also CSA certified for the North American region.
Both the PM4500E and PM4500 COsense use a Generac 224cc OHV engine, and share a similar frame design. Both have the same rated wattage too – 4500W starting, 3600W running. Where they do differ is the feature set. The 4500E comes with an electric starter and battery, so you simply push a button to get it running. Choke is automatically applied, so you don’t have to mess around with it during cold starts. It has a giant 5 gallon steel fuel tank, which gives it a runtime in excess of 10 hours at high loads (20hrs at 25% load). This is NOT an inverter generator like the Champion 100573 or 100302. As a result, it doesn’t produce clean power and runs louder. But it’s also much cheaper and generates 4600 starting watts compared to the Champion’s 4000 starting watts. You also get an extra 100 running watts. This means the PM4500E and PM4500 COsense can start tools and air conditioners that the Champion 100573 cannot.
The slightly cheaper COsense model has a carbon monoxide threat detection system which alerts you when CO levels start climbing into the uncomfortable zone. And if the sensor detects that CO levels have risen beyond permissible limits it will automatically shut off the engine to protect you. This generator doesn’t have electric start, which is a bummer. I wish Powermate made a PM4500 model with both COsense and electric start. It would probably still cost less than the Champion 100573.
So how does this Powermate cost less than the Champion while generating slightly more power? You have to understand that this generator fulfills a very different role compared to the Champion 100573. While the Champion is more of a RV/ recreational generator, the Powermate PM4500E/ PM4500 COsense generators are designed for running tools in a workshop or powering your home during emergencies. These don’t generate clean power, so you cant run your phone or laptop off them. Both PM4500 models have never-flat wheels and a folding transportation handle. Outlets are protected from dust and debris by flip-up rubber covers. The generators weigh about 105 lbs. fully assembled.
- 4500 starting watts and 3600 running watts, more than enough to handle a 1hp air compressor and 8” bench grinder simultaneously
- COsense model comes with a 3-position dial that integrates the OFF/ RUN/ CHOKE functions into one simple control
- Built with quality components, including a 224cc OHV engine sourced from Generac
- Extremely good value for money if you consider the power output and build quality
- Solid 3-year residential warranty
- 20hr runtime at 25 percent load (or approximately 10 hours on full load)
- 4500E model has push-button electric start with auto choke
- Powermate doesn’t officially mention noise levels, so I’m going to assume this isn’t something you can operate on campgrounds (like every other conventional open frame model)
- At 105lbs, this is a fairly heavy unit and you will need to install the wheel kit if you’re planning to move it around a lot
Review : A-iPower SUA4000i
- Inverter Technology
- Clean and safe power for sensitive electronics
- A-iPower / SENCI 4-Cycle OHV Engine
- Cast iron cylinder sleeves for added durability and longer life
- Low Oil Protection
- Turns the engine off when oil level is low
- 2.6-Gallon Fuel Tank w/ Fuel Gauge
- Provides up to 7 hours of run-time at 50% load
- Automatically adjusts engine speed based on demand
- Helps provides quieter operation and less fuel consumption
- Shows output indicator, low oil alarm and overload alert
- Fully-Enclosed Design For Quieter Operation
- 58 dBA at 50% Load @ 21’/ 7m
- 30-Amp 120-Volt (L5-30) Twistlock Outlet
- Includes 30-Amp RV adapter for RV applications
- Parallel Capacity : Connect (2x) A-iPower Inverters for even more power
- 8.3-Amp 12-Volt DC Outlet
- Telescopic Handle & Never-Flat Wheels
- 2-Year Residential & Commercial Warranty
A-iPower is another of those names you’ll occasionally see on generator and RV forums, but you know this isn’t a “mainstream” brand like Westinghouse, Champion, or Honda. Nevertheless, they make quality products and we’ve reviewed their products before. The SUA2000iV is an excellent alternative to the Honda EU2200i, it delivers similar performance at much lower prices. However you do sacrifice build quality and noise levels compared to a Honda.
So, how does the SUA4000i compare to more expensive inverter generators from popular brands? Well for starters, it uses an engine that is a Yamaha clone. The 7.5hp 4 stroke OHV motor is paired with a Senci alternator, Senci being a Chinese company that started production in 1990 at Chongqing. A-iPower is effectively a Chinese brand with a North American branch headquartered in Ontario and California. But at this price you can’t really get a 100% American generator with parts that are locally sourced. Even top brands like Champion and Generac outsource manufacturing to China so they can bring down costs on these low to mid-range products.
From all the research that I did on various forums, I didn’t find too many complaints regarding the reliability or build quality of A-iPower. Their generators seem to function well enough for most people. And when you consider the value proposition here it is hard to justify spending 3 times as much on a Honda. Especially if you’re just looking to power the microwave and AC in your RV during trips that you’ll make once or twice a year. For home backup though, it’s a completely different story, and investing in a WEN or Honda is well worth it in the long term. But for occasional DIY/ recreational use? An A-iPower is more than adequate and dependable enough for 99 percent of homeowners.
The SUA4000i is an inverter generator, with a closed frame design. You get clean sine wave power with THD under 3 percent, and the noise levels are also quite low. It is interesting to note that A-iPower rates this generator’s noise levels at 68 decibels when measured from a distance of 23 feet. It is unclear whether this was measured with a load attached, because Champion’s 100573 makes 64 decibels at the same distance without any load. If we follow the laws of physics it should be impossible for an open frame of similar capacity (4000 starting and 3500 running) to make less noise than a closed design. But noise measurement is a very complicated topic. Things like ambient noise, distance of measurement, attached loads, and surrounding objects can drastically change the decibel level.
Either way, it is safe to say that you’ll get a much quieter inverter if you go with Honda or WEN. However, those will cost 2 to 3 times as much for a similar wattage rating. And the A-iPower has all the usual features like a 30amp RV outlet, parallel capability, telescopic handle, never-flat wheels, etc. The inverter will automatically lower engine speed depending on load, and a digital display will show all important stats like hours, volts, watts, etc. Starting this generator should be fairly east thanks to the choke/ start/ stop combo dial. You even get a 2-year residential warranty. Runtime should be around 7 hours at 50 percent load. The noise level varied between 58 to 69 decibels depending on load, and it is going to be quieter than open frame inverter models.
- Probably the cheapest 4000 starting/ 3500 running watts closed frame inverter you can buy that isn’t terribly designed
- It uses a Yamaha engine clone, so expect good reliability and fuel efficiency
- Eco mode, automatically switches to full power if you increase the load
- Start/ Stop/ Choke integrated into single control for simple and easy starts
- Clean power with THD under 3 percent, so you can power sensitive electronic equipment
- Despite this being an inverter with a closed frame, it isn’t as quiet as a Honda or WEN inverter generator
- Don’t expect the same level of customer support as what you’ll get from Champion or Honda
Review : DuroMax XP4400E
- Includes : Electric Start, One oil funnel, One spark plug wrench, tools set, wheels and handle kit, DC charging cables and owner’s manual
- Size : 24” L x 17″ W x 17″ H. / Weight: 127 lbs
- Noise level – 69 dB. Fuel tank capacity (GASOLINE) – 3.96 gallons
- 4,400 starting watts / 3,500 running watts
- Operate at both 120 V and 240 V simultaneously, or at 120 only with full power
“A no-frills open-frame conventional generator from DuroMax that is built like a tank and delivers tons of power for all your DIY and workshop needs. It is an excellent choice for running the furnace fan or sump pump during emergencies, and can easily power any tool in your shop. The lack of clean power means you shouldn’t run sensitive electronics with this generator, but it handles everything else just fine.”
DuroMax are one of the most popular generator brands, and they make some excellent home backup generators like the XP15000EH. They do make a few low capacity (2000W and below) inverter models; however their brand isn’t as focused on inverters. Large, heavy duty open-frame generators with tons of power are what you can expect from DuroMax. And their pricing is also very reasonable.
A nice example of their DuroMax excellence is the XP4400E – a mid tier open frame generator with commercial grade parts. The 212cc OHV engine in this generator is a beast, capable of running for days on end if you keep it fueled. The heavy duty tubular steel frame with anti-rust powder coating allows this generator to be operated on jobsites. The steel fuel tank holds just 3.96 gallons of fuel, which is the only major downside to this otherwise excellent generator. For comparison, the Powermate PM4500 series has a massive 5 gallon tank.
The XP4400E stands out from other 4000w generators due to its unique MX2 power delivery system which combines both 120V circuits into a single one, significantly boosting 120V current output. This, and the fact that it also has a 240V outlet for running heavy draw tools. You can power equipment with this generator that you simply can’t with any other generator we’ve reviewed in this article. And you’ll love to hear the DuroMax manufactures their generators right at home in California. No Chinese outsourcing here.
- Rugged build quality
- All components, including the engine are made in California
- MX2 system combines both 120V circuits into one, doubling amperage
- 240V outlet, something you won’t find on most generators in the 4000W category
- Fuel capacity of 3.96 gallons, not bad but could’ve been better
- No electric start