The 2025 guide to RV generator sizing — rooftop AC wattage, 30-amp vs. 50-amp service, inverter generators, and everything you need to stay comfortable off-grid.
Choosing a generator for RV camping comes down to one question: do you need to run the rooftop air conditioner? If yes, everything else flows from that — because the AC's starting surge is the dominant load that determines minimum generator size. If no, a compact 2,000W inverter generator handles nearly everything else in an RV with ease.
💡 Want the exact watts for your setup? Use our free generator size calculator to check off your RV appliances and get a precise recommendation.
| RV Appliance | Running Watts | Starting Watts |
|---|---|---|
| Rooftop AC (13,500 BTU) | 1,500–1,700 W | 2,500–3,000 W |
| Rooftop AC (15,000 BTU) | 1,600–2,000 W | 3,000–3,500 W |
| Rooftop AC (11,000 BTU) | 1,200–1,400 W | 2,000–2,500 W |
| RV refrigerator (12V compressor) | 40–50 W | 40–50 W |
| RV microwave | 600–1,000 W | 600–1,000 W |
| RV water heater (electric mode) | 1,440 W | 1,440 W |
| TV + streaming device | 100–150 W | 100–150 W |
| Phone/laptop chargers | 100–200 W | 100–200 W |
| Electric blanket | 150–200 W | 150–200 W |
| LED lighting (interior) | 50–100 W | 50–100 W |
Your RV's shore power connector determines the maximum generator output you can use effectively:
30A × 120V = 3,600 watts. This is the maximum draw a 30-amp RV can pull from any source. A 3,000–3,500W generator covers a 30-amp RV completely. Going larger provides no benefit unless you use a 30A-to-50A adapter for flexibility.
50A × 240V (two legs) = 12,000 watts. Large fifth wheels and Class A motorhomes with dual roof ACs or electric slide toppers can draw this much. These RVs typically need a 6,000–8,000W generator to run both AC units simultaneously.
Most mid-size travel trailers and Class B/C motorhomes are 30-amp. Check the power cord at the back of your RV — a 3-prong TT-30 plug is 30A; a 4-prong 14-50 plug is 50A.
Without the AC, RV loads are modest: refrigerator (50W), lights (75W), TV (125W), chargers (150W), and occasional microwave bursts (1,000W). A 2,000W inverter generator handles all of this quietly and efficiently. The Honda EU2200i and Yamaha EF2200iS are the gold standard here.
A 13,500 BTU rooftop AC starts at up to 3,000W. Running watts (~1,600W) plus other loads (~500W) = ~2,100W continuous. You need a generator with at least 3,000W surge capacity. The Champion 3500W and Westinghouse iGen4500 hit this range perfectly.
Two 13,500 BTU units: 3,200W running + other loads (~800W) = ~4,000W continuous. Each AC surges independently (only one starts at a time), so add the larger surge (3,000W) to the running total: peak ~7,000W. A 7,500W or 8,000W portable generator covers this.
A SoftStartRV or MicroAir Easy Start device reduces your AC's starting surge by up to 70% — allowing a 2,000W inverter generator to start a 13,500 BTU unit it otherwise couldn't. This is popular among boondockers who want the weight and fuel efficiency of a small inverter generator. Cost: $200–$350 installed.
For RV camping, inverter generators are almost always the better choice. Here's why:
The trade-off: inverter generators cost more per watt. For RV use, the premium is almost always worth it.
Enough surge to start a standard 13,500 BTU roof AC, quiet enough for campgrounds, and fuel-efficient for all-day boondocking.
→ Browse 3,000W RV Inverter Generators on Amazon
Lightweight (~47 lbs), ultra-quiet, and runs all RV loads except the roof AC. The workhorse choice for tent campers and fair-weather RVers.
→ Browse 2,000W Camping Inverter Generators on Amazon
Dual AC capability, high surge rating, and enough headroom for all other loads simultaneously. Look for electric start and a wheel/handle kit — these are heavy units.
Not reliably without modification. A 13,500 BTU rooftop AC needs ~2,800W to start, which exceeds a standard 2,000W generator's surge capacity. You have two options: upgrade to a 3,000–3,500W generator, or install a soft-start module (SoftStartRV, EasyStart) that reduces the starting surge to ~800W, allowing a 2,000W inverter to handle it.
For most 30-amp RVs, a 3,000–3,500W inverter generator (Champion 3500, Westinghouse iGen4500, Honda EU3000iS) is the ideal balance of power, weight, noise, and fuel efficiency. For 50-amp rigs with dual AC, a dual-fuel 7,500W conventional generator is the practical choice.
Most RVs have a 30A TT-30 inlet or 50A 14-50 inlet on the exterior. Connect the generator's matching outlet to the RV inlet with a heavy-gauge RV power cord (10 AWG for 30A runs, or 6 AWG for 50A). Never run the generator inside the RV, in a storage bay, or within 20 feet of windows or vents due to carbon monoxide risk.
Portable generators should not be run through the night unattended — fuel can run out, and low-oil shutdowns are normal. Built-in (onboard) RV generators are designed for extended overnight use. If using a portable generator for nighttime AC, use a timer or check fuel levels before bed and keep the generator positioned safely away from the RV exterior.
Instant recommendation based on your exact appliance list.
Running and starting watts for RV appliances and more.
Wattage by BTU size and generator picks for AC cooling.
All use cases: home, RV, camping, job site, whole-home backup.