This is my review of the best generator for 15000 BTU air conditioner.
Most RV and travel trailers come with an air conditioner pre-installed on the roof. To get the AC started and running, you need to choose the right generator.
If you have a 15,000 BTU air conditioner, you’re going to need at least a 3500 Watt to get it started and about 1500 Watt to keep it running.
After spending more than 36 hours researching, I found that DuroMax XP12000EH Portable Generator is the best overall option for a 15000 BTU air conditioner.
So, in this review, I’ve included some of the standard generators, inverter generators, and best brands.
Let’s get started.
Our Best Generator For 15000 BTU Air Conditioner
- DuroMax XP12000EH Portable Generator (Best Overall)
- Champion 4000 Watt Inverter Generator (Best Wireless Remote Start Inverter Generator)
- DuroMax XP4850EH Dual Fuel Portable Generator (Affordable High-Power Dual Fuel Generator)
- WEN GN4500 Portable Generator (Best Gasoline Generator On A Budget)
- Westinghouse iGen4500 Inverter Generator (Best Midrange Inverter Generator)
- WEN GN400i RV-Ready 4000-Watt Inverter Generator (Best Inverter Generator On A Budget)
- Honda EU2200i 2200 Watt Inverter Generator (Best Quality Small Inverter Generator)
7 Best Generator For 15000 BTU Air Conditioner Reviewed
All these generators have different surge wattage, running wattage, features, and types. I didn’t mention the pricing because they are always changing.
To find out what’s the latest pricing, just click the link provided.
- Surge Wattage: 12000W (Gasoline), 10200W (Propane)
- Running Wattage: 9500W (Gasoline), 8075W (Propane)
- Engine: 457cc OHV (18 HP)
- Fuel Tank: 7.9 Gallons
- Fuel Type: Gasoline, Propane
- Run Time: 10 hours @ 50% load (Gasoline), 5 hours(5 gallons) @ 50% load (Propane)
- Outlets: 120/240V 50A Heavy Duty Outlet (x1), 120V 30A twist lock (x1),120V 30A twist lock (x1), 120V 20A standard outlets (x2)
- Noise Level: <74dBA
- Best For: Best Overall
The DuroMax XP12000EH Portable Generator is the most powerful generator on the list, and I think it is the best value for money.
It’s not the most expensive generator out there, but the quality and what it can do are excellent.
It’s a dual fuel generator that can run on gasoline and propane. This 12000 Watts generator is very powerful. It can handle almost every heavy load.
It can do a 15000 BTU AC, refrigerators, microwave, tools, lightings, and many other things. That means this generator is not just perfect for an RV but also can run your entire house.
It has a very powerful 457cc engine that produces a peak of 12000 Watts on gasoline and a peak of 8075 Watts on propane.
Although it has a bigger engine capacity, the noise level of this genny is relatively quiet. The DuroMax claims it generates less than 74 decibels. But it depends on the loads.
As this generator isn’t an inverter type, it doesn’t produce clean power, though. That’s something you should consider when using sensitive electronic devices like laptops and Smart TVs.
Based on some real owners’ reports, most of them claimed that this genny could run about 10 to 14 hours of runtime per 8-gallon fuel tank and 6-8 hours of propane.
Feature-wise, this generator has an electric start which is very handy. It comes with several outlet plugs, a voltmeter, circuit breaker, low oil alert, and an MX2 switch.
The downside of this generator is that it weighs about 224 pounds. It’s pretty heavy to move around. The wheels that are included in the package are not great and can easily go flat.
Overall for a low-cost, high-powered generator that runs on gasoline or gasoline, I think you would be hard-pressed to find another that has all the options, electric key start, and comes with the battery and all accessories included.
- High power output
- Can run an entire house
- Excellent overall package
- Reasonably priced
- The wheels are weak
- Fairly noisy
- Surge Wattage: 4000W
- Running Wattage: 3500W
- Engine: 224cc OHV
- Fuel Tank: 2.9 Gallons
- Fuel Type: Gasoline
- Run Time: 17 hours @ 25% load
- Outlets: 120V 30A RV twist lock (x1), 120V 20A standard outlets (x2), 12V USB adapter (x1)
- Noise Level: 64 dBA @23 feet
- Best For: Best Wireless Remote Start Inverter Generator
If you’re strictly looking for an RV generator, then Champion 4000-Watt Inverter Generator might be your best choice.
With 4000 starting watts and 3500 running watts, you should have no problem getting the 15k btu air conditioner started because it has extra power on it.
Being an inverter, it also produces clean power for your sensitive devices like your laptop.
What’s the cool thing about this generator is the wireless remote start system. It’s super easy to use. If you’re inside the camper, press the start button once, and you’re ready to go.
But make sure that the generator is on standby mode, and you must be within 80 feet range.
Speaking of outlet features, it gives you one standard 120V 30A for RV and two 120V 20A standard outlets for various uses.
There’s a cigarette-style 12V USB adapter that you could use to charge your phone or charge your car battery.
The parallel ports are also available to connect to another inverter generator to double up the power output. Take note that the parallel kit is sold separately.
This Champion 4000 Watt Inverter Generator generates about 64 decibels at 23 feet. A bit louder than expected but considering it’s an open case generator, that’s acceptable.
This generator is very economical. It can run up to 17 hours on Eco mode on a full tank of gasoline, providing you a longer run time before the next refill.
Overall, this inverter generator is easy to use, powerful, economical, and has excellent after-sales support. You’ll get a 3-year limited warranty with free lifetime technical support from Champion dedicated experts.
- Longer run time
- Remote start feature
- Great for sensitive electronic devices
- Excellent Champion after-sales support
- A bit noisy
- Parallel kits doesn’t include in the package
- Surge Wattage: 4400W (Gasoline); 3740W (Propane)
- Running Wattage: 3740W (Gasoline); 2975W (Propane)
- Engine: 212cc OHV (7 HP)
- Fuel Tank: 3.96 Gallons
- Fuel Type: Gasoline, propane
- Run Time:
- Outlets: 120/240V 30A RV twist lock (x1), 120V 20A standard outlets (x2)
- Noise Level: 69 dBA
- Best For: Affordable High-Power Dual Fuel Generator
The DuroMax XP4850EH Dual Fuel Portable Generator has plenty of power to run your 15000 BTU air conditioner on a hot summer.
It generates about 3740 Watts of power on propane which is more than enough to start your AC without stressing the generator.
If you have gasoline available, the generator produces about 3740 Watts of running wattage, which is a little more power than propane to run many of your appliances.
On a full tank of gasoline, it runs about 8 hours. On about 20 pounds of propane, it’ll run about 12 hours.
This generator has an electric start. You don’t have to do a lot of pulling and a lot of work to get it started, which comes in handy. It’s effortless to use in cold weather. It’s reliable and starts easy.
One of the great features is that it has an oil shutoff. If you’re running low on oil, it will shut it off. However, you shouldn’t rely on it much. The best practice is you probably want to check the oil indicator before starting the generator.
Speaking of the loudness of this generator, it produces about 69 decibels. Relatively louder, but it’s acceptable because it is an open case, and it’s not an inverter type of generator.
The generator weighs 130 pounds which is quite heavy for one person to handle. However, Duramax has provided two handles and a real kit that help you get this thing where you need it to be.
My grip on this power generator lacks a transfer-ready switch outlet for backup power for your home. But it can be easily solved by using an adapter extension cord.
If you want a powerful dual fuel generator at an inexpensive price tag, the DuroMax XP4850EH Dual Fuel Portable Generator is worth your consideration.
- 120V and 240V options available
- Easy to start (electric start system)
- Powerful even on propane
- No transfer switch ready
- Not super quiet
- Surge Wattage: 4500W
- Running Wattage: 3600W
- Engine: 212cc OHV
- Fuel Tank: 4 Gallons
- Fuel Type: Gasoline
- Run Time: 13 hours @ 50% load
- Outlets: 120V 30A RV twist lock (x1), 120V 20A standard outlets (x4), 120V 30A Transfer Switch Ready (x1)
- Noise Level: dBA
- Best For: Best Gasoline Generator On A Budget
The main advantage of this WEN GN4500 gasoline-powered generator is that it’s powerful enough to run your 15000 btu AC on your travel trailer.
The 212cc OHV engine produces a surge wattage of 4500 Watts which is plenty enough to startup your AC while running your fridge or freezer at the same, without tripping the breaker.
One full tank of gasoline can run about 13 hours at the half load, but around 10 hours is the sweet spot.
It’s because we’re likely to pull more power when running multiple appliances at the same time like TV, fridge, freezer, and AC in the summer.
Other than the attractive price, I like this generator because it can directly be hooked up to an RV or a transfer switch to your home.
Also, you’ll have four 120V 20A standard outlets that you can use to connect to all kinds of things. Plus, with the digital display, you can check the voltage, frequency, session runtime, and total runtime.
That’s a lot of features for this price range.
This generator’s least attractive feature is that it doesn’t come with a wheel and handle kit. They are sold separately. Being weighed around 100 pounds makes it hard to handle and lug around.
Another negative point to consider is that the noise level of this generator is pretty loud. But I think that’s isn’t a deal-breaker as the features outweigh its disadvantages.
- Generous voltage outlets available
- Transfer switch ready
- Powerful to run multiple appliances
- No 240V available
- The wheel and handle kit doesn’t come in the package
- The noise level is a bit noisy
- Surge Wattage: 4500W
- Running Wattage: 3700W
- Engine: 224cc OHV
- Fuel Tank: 3.4 Gallons
- Fuel Type: Gasoline
- Run Time: Up To 18 Hour Run Time
- Outlets: 120V 30A twist lock (x1), 120V 20A standard outlets (x2), 5V DC USB Ports (x2)
- Noise Level: <~52 dBA
- Best For: Best Midrange Inverter Generator
The Westinghouse iGen4500 Inverter Generator positioned itself as a midrange inverter generator at a far lower price to competing machines by Honda and Yamaha.
Although it has the same price range as the more powerful DuroMax XP12000EH Portable Generator, this Westinghouse generator produces clean power, easy to handle. It can fire up the 15k BTU AC without any issue.
Speaking of handling this generator, it weighs about 93 pounds. This lightweight generator comes with two wheels, and a telescoping handle makes it manageable to move around.
The 224cc OHV engine produces a peak of 4500 Watts and a running power of 3700 Watts. The noise level is relatively quiet, around 52 decibels, but it could be noisy when running at full load.
It will run 16 to 18 hours at 25-30% load on a full tank of gasoline. One of the real owners said it could run all night for about 10 to 12 hours with 2 of his 1500 Watts heaters.
What I like about this genny is that it comes with an LED digital display. It cycles through voltage, remaining run time, the fuel level in liters, output in kilovolts, and total run hours.
The Westinghouse iGen4500 Inverter Generator features an electric starter which makes it easy to use. However, this generator isn’t perfect.
Some owners encountered an issue with the auto choke. It wouldn’t disengage. You have to open a side panel to reset the choke for the unit to start manually.
However, I found that a disconnected plug caused this issue to the circuit board inside the unit. Another option is to call the Westinghouse support center as the generator comes with a 3-year limited warranty.
- Easy to handle
- Relatively quiet
- Adequate power for 15000 BTU AC
- I love the LED Data Center
- Plague with some choke issue
- If it comes with a manual choke would be great
- Slightly expensive
- Surge Wattage: 4000W
- Running Wattage: 3500W
- Engine: 212cc OHV
- Fuel Tank: 1.85 Gallons
- Fuel Type: Gasoline
- Run Time: 7 hours @ 50% Load
- Outlets: 120V 20A receptacles (x2), 5V USB ports (x2), 120V 30A RV outlet (x1), Parallel Connection
- Noise Level: 72-76 dBa @ 20 feet
- Best For: Best Inverter Generator On A Budget
Although the WEN GN400i generator has a similar engine capacity (212cc OHV) with the WEN GN4500 generator, the former produces less than 500W starting power than the latter.
But can it run the 15000 BTU AC on the travel trailer? The answer is YES!
The 4000 Watts starting power of this inverter generator is enough to get your 15K BTU AC started. To avoid the breaker trip, try not to run your refrigerator and microwave run simultaneously.
The generator is great for your RV, but it may not be suitable for household usage. However, if you have another generator, it has a parallel connection feature that allows you to connect to gain more power.
This inverter generator is very economical. With about ⅔ full tanks of gasoline, it can run about 7 to 8 hours runtime.
The fuel tank size is pretty small, about 1.85 gallons. As a result, it reduces the overall weight of this generator. At 66 lbs, it is very light enough to move around.
My only gripe is that thing is loud. The open frame model maybe a little louder than the closed frame but much easier to work on, and runs are a little cooler.
For a generator that can power so much with clean power for sensitive electronics, be easy to maintain, and lower cost, I feel the unit is a great buy.
It is quieter than most open frame non-inverter type generators for not much more money than those units.
- Fuel economy
- Parallel connection available
- A bit loud
- The power is a little bit weak
- Small fuel tank
- Surge Wattage: 2200W
- Running Wattage: 1800W
- Engine: 121cc OHV
- Fuel Tank: 0.96 Gallons
- Fuel Type: Gasoline
- Run Time: 6 hours @ 50% load
- Outlets: 120V 15A standard outlets (x2), DC 12V 8.3A (x1), Parallel Operation Outlets
- Noise Level: 47-57 dBA
- Best For: Best Quality Small Inverter Generator
The Honda generator needs no introduction. This small genny is very popular due to its high quality, super-quiet operation, lightweight, and long-lasting.
You might be wondering why Honda EU2200i is on the list. Can this small generator run the 15000 BTU air conditioner in my travel trailer?
Yes! You can run it in 2 ways.
The first method is by installing a soft start on your AC. The initial starts of 15k BTU AC pull about 30 Amp.
So what the soft start does is reducing the starting amps of your AC unit by almost half. This small power drawn won’t trip your breaker.
Once the AC is running, the Honda generator should be able to handle it. The price range of the soft-start kit is varied depending on the models.
The second method is to run it parallel with another similar generator to deliver enough power to start the AC. In this case, it’s better to have another Honda EU2200i for the best companion.
Regardless of the method you choose, to run this generator on RV, you’re going to need an accessory adapter to connect the two generators electrically. This generator doesn’t have a 120V 30A RV outlet.
So, the adapter has a 30 amp RV plug and allows the connection to the RV.
If only one generator is being used (15 amps), an adapter plug is required to connect the RV 30 amp cable to the generator 15 amp plug.
One advantage of having dual generators and a parallel kit is that the other still works if one dies. Besides, it’s easier to carry a small generator around than bulky generators.
The downside of it, you end up getting tired of changing oil for two generators and keeping track of hours on each of them.
- Reliable and proven generator
- Small and easy to carry
- Fuel economy
- Super quiet
- Lack of features
- No 120V 30A for RV connection
Guide To Buying A Generator For 15000 BTU Air Conditioner
There are seven main factors to consider when selecting the best generator for a 15000 BTU air conditioner:
As mentioned in the early post, the 15000 BTU RV air conditioner requires at least 3500 starting watts (or surge wattage) to start up.
Once it’s running, the AC only needs an estimated about 1500 to 2000 watts. 
If you’re looking for a single power generator to run your AC, microwave, TV, refrigerator, freezers, and lighting, any generator with starting watts from 4000 watts is a good start.
If you hate these generators’ bulkiness and loudness, you can opt for a smaller generator like the Honda EU2200i.
But choosing this route will require you either to run in parallel with another generator or by using a soft start kit.
Conventional Vs. Inverter Generator
The conventional or standard generator is generally more robust and relatively cheaper than the inverter generator.
You can get the 12000W generator and the same price range as the 2200W inverter generator—for example, the DuroMax XP12000EH and the Honda EU2200i generators.
Furthermore, most conventional generators have the 120V 30A outlet ready for travel trailers.
One of the drawbacks of conventional generators is that they’re not suitable for your sensitive devices like laptops because of the “dirty” power.
On the other hand, the inverter generator is quieter in operation and produces clean power that is safe for your laptop and Smart TV.
The disadvantage of the inverter generator is that they’re generally more expensive.
There are two common types of fuel for the generator that are gasoline and propane.
The generator does provide a little more power when it runs on gasoline than on propane. But the advantage of propane is that you have propane around all the time.
If you want more efficient fuel and more power, choose gasoline. 
If you want something easy to store and cleaner-burning fuel, pick the propane.
I recommend you get a hybrid generator. Propane lasts twice as long, but gasoline is there for your trip to the propane refill if you run out.
Ideally, you want to choose a generator that has a longer runtime. You don’t want to wake up on a cold night to refill the fuel.
However, you just can’t rely on the run time as a single factor alone in choosing the right generator for you.
The run time is hard to gauge depending on several factors:
- The size of a fuel tank (for gasoline)
- The size of the propane bottles
- The load. The more appliances you run at the same, the load will increases
- Engine capacity and efficiency
On average, the run time sweep spot of the run time is between 10 to 18 hours on gasoline.
I’m pretty sure that you’re a good neighbor. When you’re going to a campsite, the first thing you worry about is the loudness of your generator.
You don’t want your neighbors to hate you.
The source of noise is coming from the engine. The bigger the engine, the louder it gets.
Generally speaking, a noise level below 60 decibels is considered quiet. A typical conversation is about 60 decibels. 
Anything above that might be annoying to some people.
When it comes to loudness, the open case generator is the worst. The solution could be either putting it a bit far away from your RV or investing in a portable generator enclosure.
The panel includes a wide selection of outlets for maximum compatibility in your applications. Some of the features that you can find on the panel are:
- AC 120/240V 30A twist lock – to connect to RV
- AC 120V 20A outlets – for misc
- USB ports
- Parallel Operation Ports
- 120V 30A Transfer Switch Ready
- Display meter – to display various information
- Engine start switch
- Low oil indicator
All these features do vary depending on the product.
If you’re Californian or plan on camping in California, you also need to ensure that the generator complies with the California Air Resource Board (CARB) requirements. 
The industry standard rates the minimum number of hours a portable generator can run before exceeding emission requirements.
Some of the most efficient generators can run for 500 hours before producing high carbon emissions levels, while others can operate for about 250 hours.
I’ve found that inverter generators are more likely to be CARB compliant, as they are naturally more efficient than conventional generators.
Here are some answers to frequently asked questions about a generator for 15000 BTU air conditioner:
What size generator do I need for a 15000 BTU air conditioner?
A 15000 BTU air conditioner needs at least 3500 Watts to start up. As a general rule of thumb, you should look for a power generator with surge wattage or starting wattage at least 3500 Watts and above.
If you’re running two paralleled generators, make sure the combination of power output from those generators produces more than 3500 Watts.
How many watts does it take to run a 15000 BTU air conditioner?
The average watts once the air conditioner is running estimated at 1500 Watts.
What’s the difference between surge watts and running watts?
Think of the running watts as the generator stabilizing its power output & staying level. When you plug another item into it, that means it has to do more or output more power for a few seconds. It amps up to compensate for the new item plugged in.
A quick surge in watts happens & eventually levels out back to the running watts. If it happens to go over the max surge watts too far, it’ll shut off.
Will a 3500 Watt generator run a 15000 BTU AC?
Will a Honda 2000 run a 15k AC?
The Honda 2000W has a 2000 Watts starting power. So, it’s insufficient to start a 15k AC by itself alone. You might want to either use the soft start kit or run parallel with another Honda 2000W to double the power output.
A 15000 BTU Air Conditioner needs a lot of power to start up. Thus, you need a powerful generator.
When it comes to power output, features, price, and versatility, I would recommend the DuroMax XP12000EH Portable Generator to everyone.
This generator has more than enough power to run your AC, freezers, fridge, and many other devices. It also has dual fuel options, which are very handy.
If you are not using it on an RV or travel trailer, this generator is still handy to use as home backup power during hurricanes and power outages.
I hope this list comes in handy for you.
Hey there, my name is Joe and I am the person behind this website. I am an electrical engineer and I created this site to share my knowledge of the generator. I hope this will help you. Read more about me.