A 13,500 BTU rooftop RV air conditioner draws about 1,500 watts running and a 15,000 BTU unit about 1,700-1,900 W. Without a soft starter, expect a start surge of roughly 2,800-4,000 W.
- Running watts
- 1,600 WTypical; 1,300–2,000 W across models
- Starting watts
- 3,000 WWithout a soft starter a 13,500 BTU unit can surge to about…
- Per day
- 7.7 kWh8 h of use, cycling
- Current
- 13.3 AAt 120 V while running
Figures checked against DOE, ENERGY STAR and manufacturer data on . Your model's label is the final word.
Watts by model and setting
Most rv air conditioner models draw between 1,300 and 2,000 W while running; a typical one draws about 1,600 W. Assumes 8 hours of use with the compressor running about 60% of the time on a hot day; 1,600 W x 8 h x 0.6 = about 7.7 kWh.
- Capacity: 13,500 BTU units draw about 1,500-1,670 W, 15,000 BTU units about 1,700-1,950 W
- Outdoor heat and sun load: running watts rise as it gets hotter
- Low voltage at a campground pedestal or long cord raises current and stresses the compressor
- Heat pump models and heat strips have different draws in heating mode
- A soft-start kit lowers the compressor's start surge, not its running watts
Running an RV air conditioner on a generator or power station
- Generator: at least 1,600 running watts and 4,600 starting watts (running plus the 3,000 W start surge, the cautious way to size it). Check both numbers on the spec sheet. A generator rated 5,500 W or more covers it with room to spare.
- Power station: continuous output of at least 1,600 W and a surge rating that covers about 3,000 W. Pure sine wave output is the safe choice for motors and electronics.
| Power station capacity | Estimated runtime |
|---|---|
| 500 Wh | 0.4 h |
| 1,000 Wh | 0.9 h |
| 2,000 Wh | 1.8 h |
| 3,000 Wh | 2.7 h |
Based on 960 W average draw (running watts × duty cycle) and 85% usable capacity.
- Without a soft starter a 13,500 BTU unit typically needs a 3,000 W+ generator, and a 15,000 BTU unit about 4,000 W; with a soft starter about 2,000-2,200 W can work
- A soft-start kit is an add-on module wired into the AC unit's compressor circuit that ramps the motor up gradually; it lets smaller inverter generators and large power stations start the AC
- Running an RV AC on batteries takes big capacity: at about 1,500 W, a 3 kWh battery bank lasts roughly 2 hours of compressor run time
- Point the generator exhaust away from the RV, its windows, vents and neighbors' campsites; carbon monoxide can enter through slide-outs and vents. Keep CO alarms working.
Add it to the generator calculator
Questions people ask
What size generator do I need for a 15,000 BTU RV air conditioner?
About 4,000 W without a soft starter, because start-up can surge to 3,500-4,000 W. With a soft-start kit, many owners run one on a 2,200-3,000 W inverter generator.
Can a 2000 watt generator run an RV air conditioner?
Usually not without a soft starter, since a 13,500 BTU unit can surge to around 3,000 W. With a soft-start kit, a 2,000-2,200 W inverter generator can often start and run a 13,500 BTU unit in moderate heat.
Can a portable power station run an RV air conditioner?
Only a large one: it needs about 1,500-1,900 W continuous output, a surge rating high enough for the start (or a soft starter), and several kWh of battery for more than an hour or two of cooling.
Sources
- Dometic Brisk II 13.5K BTU rooftop AC specifications (1,670 W cooling, ISO 5151)
- Dometic Brisk II 15K heat pump specifications (1,725 W cooling, ISO 5151)
- Micro-Air: What size generator do you need to run an RV air conditioner
- Generac portable generator brochure: wattage reference chart (approximate running and starting watts)