Portable power from RV power specialists

Pick the right dual-fuel generator for your RV.

Run on gasoline or your RV’s propane. Compare the 3300ies, 4500ies and 6500ies by what you want to power, how you connect, and how you want to start it.

  • 3 Dual-fuel sizes
  • 2 Fuels: gas or propane
  • 2 yr Warranty
Flex Power 3300ies dual-fuel generator beside an RV
Flex Power® 3300ies Dual Fuel + Electric Start Silent Portable Inverter Generator

Flex Power 3300ies Dual Fuel

  • Gas or propane
  • Electric or pull start

46 lbs · 3,300 starting / 2,700 running watts on gas, 10% less on propane · 30A RV outlet

Best if you run the essentials and want the easiest one to carry.

$779

In stock. Ships from Columbus, OH. Free shipping in the contiguous U.S.

See full specs
FlexPower® 4500ies Quiet Inverter Generator with Electric Start

Flex Power 4500ies Dual Fuel

  • Gas or propane
  • Electric, pull or fob start

78 lbs · 4,500 starting / 3,800 running watts on gas, 10% less on propane · 30A RV outlet

Best if you want the A/C plus other big loads on a 30-amp RV.

$1,099

Ships from Columbus, OH. Free shipping in the contiguous U.S.

See full specs
FlexPower® 6500ies Quiet Inverter Generator

Flex Power 6500ies Dual Fuel

  • Gas or propane
  • Electric, pull or fob start

109 lbs · 6,500 starting / 5,500 running watts on gas, 10% less on propane · 30A RV outlet and 120/240V 30A twist-lock outlet (L14-30)

Best if you want the most output and 120/240V for a bigger rig.

$1,399

In stock. Ships from Columbus, OH. Free shipping in the contiguous U.S.

See full specs

Not sure? Get a recommendation in 60 seconds · Call an RV power specialist · Don’t need propane? Gas-only versions cost less

Which one fits your RV?
Check in 60 seconds.

Tick what you’ll run and our wattage calculator recommends the generator that fits.

Open the wattage calculator

Compare the three

Same fuel choice, three sizes. Pick by what you want to run and how your RV connects.

Compare the three
Spec3300ies Dual Fuel4500ies Dual Fuel6500ies Dual Fuel
Price$779$1,099$1,399
Output on gas (start / run)3,300 / 2,700 W4,500 / 3,800 W6,500 / 5,500 W
Output on propane2,430 W running (10% less than gas)3,420 W running (10% less than gas)4,950 W running (10% less than gas)
RV connection30A RV outlet (all three)
Voltage120V/60Hz120V/60Hz120/240V
StartElectric and pull startElectric, pull and remote-fob startElectric, pull and remote-fob start
Weight46 lbs78 lbs109 lbs
Runtime, 50% load6–7 h on gas; ~8 h on a 20 lb propane cylinder8–10 h on gas; 10–12 h on a 20 lb propane cylinder10 h on gas; ~12 h on a 20 lb propane cylinder
Gas tank1.53 gal1.9 gal3.6 gal
Noise59 dBA at 23 ft57 dBA at 23 ft60 dBA at 23 ft
At 5,000 ftAbout 2,230 wattsAbout 2,970 wattsAbout 4,540 watts
Size18×12×20 in24×12×22 in23×17×20 in
Outlets2×120V GFCI, 30A RV, USB-A, USB-C, 12V DC, parallel4×120V GFCI, 30A RV, USB-A, USB-C, 12V DC, parallel2×120V GFCI, 30A RV, 120/240V 30A twist-lock, USB-A, USB-C, 12V DC, parallel
In the boxEngine oil, oil funnel, spark plug toolkit and owner’s manual, LP hose with regulatorEngine oil, oil funnel, spark plug toolkit and owner’s manual, remote key fob, LP hose with regulatorEngine oil, oil funnel, spark plug toolkit and owner’s manual, remote key fob, LP hose with regulator
Warranty2 years on manufacturing defects (all three)
Buy
$779

In stock

$1,099

Ships from Columbus, OH

$1,399

In stock

Don’t need propane?3300i (gas only): $639Save $1404500ies (gas only): $849Save $2506500ies (gas only): $1,299Save $100

Want more power later? Two matching generators connect with a parallel kit. Same size only; a pair of 6500s also gives you 240V.

Gas or propane: what changes

Output

On propane, every dual-fuel model makes 10% less power than on gasoline. The 3300ies makes 2,430 running watts, the 4500ies 3,420 and the 6500ies 4,950. If your loads are close to the limit, size up or plan to run on gas.

Runtime

At half load, the 4500ies runs about 10–12 h on a 20 lb propane cylinder, versus 8–10 h on a full tank of gas.

Storage

Propane keeps for years without going stale, so it’s ready when the generator has sat all winter. Gasoline should be 87 octane or higher, ideally ethanol-free, and never E15 or E85.

Hookup and price

Every dual-fuel model includes an LP hose with regulator for a 20 lb propane cylinder, the same size as a gas grill tank. Dual fuel costs a little more than the gas-only version of the same model; the prices are under the comparison.

How it connects to your RV

30-amp RVs

The 3300ies, 4500ies and 6500ies all have a 30-amp RV outlet, so your shore power cord plugs straight in. A 30-amp RV can draw up to 3,600 watts. The 3300ies supplies 2,700 running watts on gas, enough for the essentials. The 4500ies supplies 3,800, so it covers far more of what a 30-amp RV can use at once. The 6500ies supplies 5,500, more than a 30-amp RV can draw.

Up to 240V

The 6500ies has a 120/240V 30A twist-lock outlet (L14-30) and makes 5,500 running watts on gas. Call us to confirm the fit for your rig if you have any questions.

Running your air conditioner

The 3300ies runs most RV roof A/Cs on gas. The 4500ies and 6500ies run the A/C with room left for other big loads like the microwave. Your setup depends on the A/C’s size, whether it has a soft start, fuel, altitude and outside temperature. Use our wattage calculator to gauge your setup, or tell our specialists your A/C model and we’ll give you a straight answer.

More power from two units

Two matching generators (two 3300s, two 4500s or two 6500s) connect with a parallel kit. Don’t mix sizes or brands. A pair of 3300s or 4500s puts out 120V; a pair of 6500s also gives you 240V.

What owners say

4.7
Rated 4.7 out of 5 Based on 184 verified reviewsRead all reviews →

Due to the excellent and diligent efforts of Grant and the staff at RVMP, I received the 4500 watt generator I ordered well before my departure date. The Onan generator in my RV went out while en route to Florida. What a blessing they are.

Jim F.RV owner · 4500 watt generator
5 out of 5 stars
“Best generator I have ever owned. Remote start is awesome. This is my second purchase.”
Peter F. Verified buyer 4500ies Gas
5 out of 5 stars
“Set up was easy. Fired right up with both hand pull and with key fob. Quiet as advertised. Very pleased with the weight and dimensions.”
Russell B. Verified buyer 4500ies Gas
5 out of 5 stars
“Shipped quickly, no messing around, and it is quieter than Honda and lighter. Very nice unit.”
Randall L. Verified buyer 4500ies Gas

What you get when you order

Flexible payments
Pay in full with a credit card, PayPal or another express payment option, or pay over time with Shop Pay.
Shipping
Free standard shipping in the contiguous U.S. Ships from Columbus, OH. You’ll get tracking by email as soon as the label is created. Need it faster? Call (855) HappyRV for an expedited quote.
Warranty
2 years on manufacturing defects.
Returns
Return it unused, in its original packaging, within 30 days of delivery. Email support@rvmp.co first and we’ll send instructions. Return shipping is paid by the customer.
In the box
Engine oil, oil funnel, spark plug toolkit, LP hose with regulator and owner’s manual, plus a remote key fob with the 4500ies and 6500ies.
U.S.-based generator pros
Our hands-on support team is based in the U.S. We’re headquartered in Columbus, OH, and our generators are engineered in Elkhart, IN. Flex Power is a division of RV Mobile Power LLC, a leader in RV generator technology for nearly a decade.

Portable power from RV power specialists

Flex Power is made by RVMP (RV Mobile Power), founded in Columbus, Ohio in 2017. RV power is what we do. We design and engineer every Flex Power generator in the U.S. Our portable inverters are built by manufacturing partners overseas to RVMP’s designs.

When you call, you reach our support team in Columbus, not a call center reading a script. Tell us your rig and what you want to run, and we’ll tell you straight which generator fits, including when the smaller, cheaper one is enough.

Not sure which one fits your rig? Ask an RV power specialist.

Tell us your RV and what you want to run. A real person on our Columbus team will tell you which generator fits, and whether it’ll handle your A/C.

Call (855) HappyRV

Mon–Fri, 9am–5:30pm ET

Or send a question

Questions RV owners ask

Which one do I need for a 30-amp RV?

If you run the essentials (fridge, lights, fans, TV, coffee), the 3300ies. If you want the A/C plus other big loads, or you’ll run on propane near the limit, the 4500ies. Our wattage calculator does the math.

Which one for a 50-amp RV?

None of them has a 50-amp outlet. The 6500ies comes closest: 5,500 running watts on gas and a 120/240V 30A twist-lock outlet (L14-30). Call us to confirm the fit for your rig if you have any questions; some 50-amp owners run fine on less.

How much power do I lose on propane?

10% of running watts on every model. On propane the 3300ies makes 2,430, the 4500ies 3,420 and the 6500ies 4,950 running watts. Size with that in mind.

Will it run my RV air conditioner?

The 3300ies runs most RV roof A/Cs on gas. The 4500ies and 6500ies run the A/C with room for other big loads. Start the A/C before other big loads like the microwave or coffee maker, and a soft-start kit lets you run more alongside it. Questions about your rig? Ask a specialist.

How do I hook up propane?

Every dual-fuel model includes an LP hose with regulator for a 20 lb propane cylinder, the same size as a gas grill tank. Full steps are in the owner’s manual.

Can I run two together?

Yes, two of the same size with a parallel kit. Output stays 120V.

How long does it run?

At half load:

  • 3300ies: 6–7 h on gas, ~8 h on a 20 lb propane cylinder
  • 4500ies: 8–10 h on gas, 10–12 h on a 20 lb propane cylinder
  • 6500ies: 10 h on gas, ~12 h on a 20 lb propane cylinder
What’s in the box?
  • 3300ies: Engine oil, oil funnel, spark plug toolkit and owner’s manual, LP hose with regulator
  • 4500ies: Engine oil, oil funnel, spark plug toolkit and owner’s manual, remote key fob, LP hose with regulator
  • 6500ies: Engine oil, oil funnel, spark plug toolkit and owner’s manual, remote key fob, LP hose with regulator
What’s the warranty and return policy?

2 years on manufacturing defects. Return it unused in original packaging within 30 days of delivery; contact support@rvmp.co first. The customer pays return shipping.

How fast will it ship?

3300ies: In stock. Ships from Columbus, OH.4500ies Dual Fuel: Ships from Columbus, OH.6500ies Dual Fuel: In stock. Ships from Columbus, OH. Free standard shipping in the contiguous U.S.

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