Quick answer: an RV generator supplies 120-volt power when you are not plugged into a campground pedestal. Onboard generators are built into many motorhomes, while trailer owners often use portable inverter generators, which are quieter and produce cleaner power for electronics. A 30-amp RV can draw up to about 3,600 watts and a 50-amp RV up to about 12,000 watts, but most campers size a generator for what they actually run, often 2,000 to 4,000 watts. The biggest risk is carbon monoxide, so keep generators outdoors, exhaust pointed away from the RV and windows, and test your CO alarm before every trip. Check park generator hours and quiet hours before you start one.
A generator turns an RV into a self-contained home on wheels, powering the air conditioner on a hot afternoon, the microwave at dinner and battery charging when solar is not enough. It can also be the most annoying thing in a campground and, used carelessly, a genuine danger.
This guide explains how RV generators work, how to choose and size one, which fuels make sense, how to use one safely and how to stay on good terms with your neighbors and the rules. For the broader picture of RV travel, see our RV and van camping guide.
Sources: U.S. Consumer Product Safety Commission (CPSC) portable generator and carbon monoxide safety guidance; Centers for Disease Control and Prevention (CDC) carbon monoxide poisoning prevention; National Park Service regulations at 36 CFR 2.12 (audio disturbances) and park camping pages; National Fire Protection Association (NFPA) 1192 Standard on Recreational Vehicles; RV Industry Association (RVIA) resources; generator manufacturer owner’s manuals for maintenance intervals. Checked October 2026.
What an RV Generator Does
Your RV runs on two electrical systems. The 12-volt DC system, powered by the house batteries, runs lights, the water pump, fans, the furnace blower and control boards. The 120-volt AC system runs household-style outlets and larger appliances such as the air conditioner, microwave, coffee maker and, in many rigs, the refrigerator on electric mode.
At a campground with hookups, shore power feeds the 120-volt system and the converter charges the batteries. Off grid, a generator replaces shore power. Plug the RV into the generator (or start the onboard unit), and the RV behaves as if it were connected to a pedestal, within the generator’s limits.
For a deeper look at the battery side of the system, read our guide to RV battery basics.
Types of RV Generators
Onboard (built-in) generators
Many Class A and Class C motorhomes, and some larger fifth wheels and toy haulers, come with a generator mounted in a compartment. These usually run on the coach’s gasoline, diesel or propane supply, start from a switch inside the RV and connect automatically through a transfer switch. Common sizes range from about 3,600 to 8,000 watts or more.
Pros include convenience and no setup, while downsides are weight, cost and noise levels that vary widely by model.
Portable inverter generators
Inverter generators produce AC power, convert it to DC and then invert it back to a clean AC waveform. The result is stable voltage suited to laptops, TVs and RV control boards. They also throttle engine speed to match the load, which makes them quieter and more fuel efficient at light loads. Many models can be paired with a second identical unit using a parallel kit to double available power.
Portable inverter generators in the 2,000 to 4,500 watt range are popular with travel trailer owners because they are light enough to lift and quiet enough for campgrounds that allow generators.
Open-frame (conventional) generators
Open-frame generators run at a constant engine speed and are common for home backup. They usually cost less per watt but are louder, heavier and may produce power with more distortion. Many campgrounds and public lands have noise limits that open-frame units struggle to meet.
How to Size an RV Generator
Know your RV’s electrical service
RVs are typically wired for 30-amp or 50-amp service:
| Service | Configuration | Maximum power |
|---|---|---|
| 30-amp | One 120-volt leg | About 3,600 watts (120 V x 30 A) |
| 50-amp | Two 120-volt legs | About 12,000 watts (2 x 120 V x 50 A) |
Few campers need the full theoretical capacity. A generator only has to cover what you run at the same time.
Running watts vs starting watts
Generators list two numbers. Running (rated) watts is what the generator can supply continuously. Starting (surge or peak) watts is the brief extra power available when a motor kicks on. Air conditioners, refrigerators and some pumps need a burst of starting power that can be two to three times their running draw. Owner’s manuals or appliance labels list the exact figures.
Typical appliance loads
The figures below are approximate ranges; check your appliance labels for real numbers.
| Appliance | Approximate running watts |
|---|---|
| Rooftop air conditioner (13,500 BTU) | 1,200 to 1,700 (higher to start) |
| Rooftop air conditioner (15,000 BTU) | 1,400 to 2,000 (higher to start) |
| Microwave | 1,000 to 1,500 |
| Electric water heater element | About 1,400 |
| Coffee maker | 800 to 1,200 |
| Converter charging batteries | 300 to 1,000 depending on charge rate |
| Refrigerator on electric | 300 to 600 |
| TV and electronics | 100 to 300 |
A simple sizing method
- List what you want to run at the same time.
- Add up their running watts.
- Add the highest single starting surge, usually the air conditioner.
- Choose a generator whose running watts cover the total, with some margin.
Many 30-amp trailers can run one air conditioner and a few small loads from a 3,000 to 3,500 watt inverter generator. A soft-start device added to the air conditioner reduces the startup surge and can make a smaller generator work, as many RV owners and manufacturers note. Running two air conditioners on a 50-amp rig usually takes 5,500 watts or more.
Gas, Propane or Diesel
| Fuel | Pros | Cons |
|---|---|---|
| Gasoline | Widely available, most common for portables | Stale fuel gums up carburetors; storage hazards |
| Propane | Stores indefinitely, cleaner burning, shares RV tanks | Usually about 10% less power output; tanks need monitoring |
| Diesel | Efficient, common on diesel motorhomes | Heavier, more expensive units |
| Dual fuel | Flexibility between gas and propane | Slightly higher purchase price |
Propane is popular with RVers because many rigs already carry it and it does not go stale. If you use propane, follow the safety practices in our RV propane safety guide for connections, leak checks and tank storage.
Carbon Monoxide Safety
Carbon monoxide (CO) is the most serious generator hazard. It is colorless and odorless, and it can build to dangerous levels quickly. The CPSC reports that portable generators are linked to dozens of CO deaths in the United States each year, and the CDC lists symptoms of CO poisoning as headache, dizziness, weakness, upset stomach, vomiting, chest pain and confusion. People who are asleep or drinking alcohol can die before they notice symptoms.
Safe placement
- Never run a generator inside an RV, a vehicle, a tent, a garage, a camper shell or any enclosed or partly enclosed space.
- Place portable generators outdoors and well away from the RV, with the exhaust pointed away from doors, windows, vents and neighbors’ campsites.
- Watch the wind, which can carry exhaust back toward your rig or the campsite next door.
- Do not put a portable generator in a truck bed or pickup camper while running, unless the manufacturer specifically permits a vented setup.
- For onboard generators, check that the exhaust pipe is intact and not blocked by snow, mud, a berm, tall grass or a wall, and avoid parking with the exhaust facing an obstruction.
CO alarms
NFPA 1192, the standard RV manufacturers follow, requires CO alarms in RVs with fuel-burning appliances or generators. Test the alarm before each trip and replace it at the end of its service life, which is printed on the unit. Replace the battery if it is battery powered. If the CO alarm sounds, get everyone outside into fresh air immediately, turn off the generator and call 911 if anyone feels ill.
Our guide to tent safety and carbon monoxide explains why CO is just as dangerous in tents and camper vans.
Other Generator Safety Points
- Refuel only when the generator is off and cool. Spilled gasoline on a hot engine can ignite, as the CPSC warns.
- Store gasoline in approved containers, away from the RV living space and ignition sources.
- Keep the generator dry. Use a cover or tent designed for generators in rain, never an enclosure that traps exhaust.
- Use heavy-duty, outdoor-rated cords sized for the load, and do not run them through windows or doors where they can be pinched.
- Keep children and pets away from hot exhaust and moving parts.
- Never backfeed power into a home or building through an outlet.
Grounding and surge protection
Many portable inverter generators have a floating neutral, which means the neutral and ground are not bonded inside the unit. Some RV surge protectors and energy management systems read this as an open ground and refuse to pass power. Generator and surge protector manufacturers describe using a neutral-ground bonding plug in this situation. Check your generator’s manual and your surge protector’s instructions before using one.
Generator Rules, Hours and Etiquette
National parks and public lands
National Park Service regulations at 36 CFR 2.12 prohibit operating motorized equipment, including generators, in a way that exceeds 60 decibels measured on the A-weighted scale at 50 feet, or in a way that is unreasonable considering the time of day and impact on others. Many parks also set specific generator hours, often a few blocks of time in the morning, midday and evening, and some campgrounds or loops ban generators entirely. Check the campground page on the park website or Recreation.gov before you go.
National forests, BLM land, state parks and private campgrounds have their own rules, typically including quiet hours, often from 10 p.m. to 6 a.m. or similar.
Being a good neighbor
- Run the generator only when you need it, and combine tasks such as charging and cooking.
- Point the exhaust and the loudest side away from neighboring sites.
- Turn it off during quiet hours, even if it is technically allowed.
- Consider solar panels and a larger battery bank to reduce generator time.
See our guide to campground etiquette for more on sharing space well.
Generator Maintenance
Generators that sit unused are the ones that fail to start. Manufacturer manuals list exact intervals, but these habits apply broadly:
- Change the oil on the schedule in the manual, usually more often for new engines during break-in.
- Exercise the generator regularly, often monthly, by running it under a moderate load for the time the manufacturer recommends.
- Use fresh fuel, add a fuel stabilizer for storage or run the carburetor dry if the manual recommends it.
- Check and clean or replace the air filter.
- Inspect the spark plug and spark arrestor screen.
- Keep the unit clean and free of debris, especially around cooling vents.
- Inspect the exhaust system on onboard units for leaks, rust and damage.
Many onboard generators also log hours on a meter, which helps you track service intervals.
Alternatives and Supplements to a Generator
Solar panels, lithium batteries and portable power stations can handle lights, fans, phones, laptops and the furnace blower without any engine noise. They usually cannot run a rooftop air conditioner for long without a large, expensive system. Many RVers combine solar for daily loads with a generator for air conditioning and rainy stretches. Our guide on RV boondocking for beginners covers power planning for off-grid stays.
RV Generator Summary
An RV generator replaces shore power when you are off grid. Choose an onboard unit for convenience, or a portable inverter generator for quiet, clean power and flexibility. Size it based on what you actually run at the same time, remembering that 30-amp rigs top out around 3,600 watts and that air conditioners need extra starting power. Pick a fuel that suits your rig, keep the generator outdoors with exhaust aimed away from people and test the CO alarm before every trip. Respect generator hours and quiet hours, and keep up with oil changes and regular exercise runs so the generator starts when you need it.
Frequently Asked Questions
What size generator do I need for my RV?
Add up the running watts of what you will use at the same time and the largest starting surge, usually the air conditioner. Many 30-amp trailers do well with a 3,000 to 3,500 watt inverter generator, while 50-amp rigs running two air conditioners often need 5,500 watts or more.
Can I run my RV generator while sleeping?
Only if the generator is outdoors, the exhaust is clear and pointed away from the RV, the CO alarm is working and campground rules allow it. Most campgrounds ban generators during overnight quiet hours.
Is an inverter generator better for an RV?
For most campers, yes. Inverter generators are quieter, more fuel efficient at light loads and produce stable power that suits RV electronics.
Can I run an RV generator on propane?
Yes, propane and dual-fuel generators are common. Propane stores well and burns cleanly, though it usually produces slightly less power than gasoline.
What are generator hours in national parks?
They vary by park and campground. NPS rules limit generator noise to 60 dBA at 50 feet, and many parks set specific generator hours; check the campground’s page before your trip.
