What size generator do I need to run an RV air conditioner?

Q: What size generator do I need to run an RV air conditioner?

Plan on at least 2350 running watts and 3450 watts of surge capacity. That covers 1845W of running load plus the largest start-up surge, with 25% headroom.

The 13,500 BTU rooftop AC defines RV generator sizing — its starting surge is what separates the generators that work from the ones that almost work.

The load

RV air conditioner (13,500 BTU) — 1300W running, 2900W starting
RV converter/charger — 500W running
Wi-Fi router + modem — 15W running
LED lights (per room) — 30W running

SIZING PLATE4 LOADS · +25% HEADROOM

Total running watts

1,845 W

Peak (largest start)

3,445 W

Buy at least

2,350 W rated

Look for ~2,350W running / 3,450W surge or better.

Field note: A soft-start kit (roughly a hundred dollars installed) can cut the AC's starting surge nearly in half and let a smaller, quieter, lighter generator do the job. It's often cheaper than buying the next generator size up.

Right size: Mid-size inverter (3,500W / 4,000W surge)

Typical price $600-1,400 · e.g. Champion 4250 open-frame inverter, Westinghouse iGen4500, Generac GP3500iO

RV 13,500 BTU AC (especially with soft-start), fridge + window AC, storm essentials for smaller homes. The sweet spot of quiet, portability, and real capacity for most first-time buyers.

See current prices on Amazon

One size up: Mid-size portable (6,500W / 8,100W surge)

Typical price $700-1,200 · e.g. Westinghouse WGen6500, Champion 6250, Generac GP6500

Storm essentials with margin: fridge, freezer, sump pump, furnace fan, well pump (240V models), lights and electronics together. Louder open-frame design; electronics prefer models with THD under 5% or an inverter.

See current prices on Amazon

Adjust for your setup

Different fridge? Bigger AC? Uncheck and re-check below — the plate recomputes live.

This site earns commissions from qualifying purchases made through links to Amazon and other retailers, at no extra cost to you. Wattage figures are typical estimates — actual draw varies by model. Always verify against your appliance's nameplate, and consult a licensed electrician for any panel or hardwired connections.