Home > All Products > Generators > Portable Generators > GP Series > GP3500iO
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Model #7128

Starting At

$789.00 MSRP
Where To Buy

Introducing the GP3500iO Open Frame Inverter featuring PowerRush™ Technology.

The Generac GP3500iO open frame inverter featuring new, advanced PowerRush™ technology delivers over 50 percent more starting capacity for tools and other motor-driven equipment—so you can do more with less.* Both quieter and lighter, it’s the ideal portable solution for camping, powering your RV essentials or tools.

Over 50 percent more starting capacity with new, advanced PowerRush™ technology so you can do more with less*

50 percent quieter for noise sensitive environments

25 percent lighter, helping reduce fatigue while improving portability

Clean power for sensitive electronics with TruePower

One simple-to-use dial that integrates start/run/stop functions with PowerDial

*Increases electrical current upon demand; above rated output when starting electric motors.


The Power to
Live. Work. Play.

Portable generators are a welcome addition to many activities at home, at work, and away. In an emergency, portable generators can provide critical backup power. They make camping and tailgating more comfortable. And contractors appreciate the flexibility portable power brings to the jobsite.

GP Series Accessories

Maximize your investment and maintain your Generac portable generator with a variety of accessories.

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Enjoy writing your review!

Rated 5 out of 5 by from Great Service Purchased due to Hurricane. Twenty six days without power and generator never skipped a beat. Changed oil as recommend and allowed to cool down at each re-fill of fuel. Connected directly to home and ran ceiling fans, all lighting, freezer, refrigerator and two window units. Easy start and CO2 SENSOR. Highly recommend.
Date published: 2020-12-09
Rated 5 out of 5 by from Great relief in time of need!!!! Machine worked great. Found in our home town Generac dealer/installer(?). Used for 2 full days. Kept our ac on for necessity and saved some food Great investment for home owner. Would highly recommend it for the price and value. Thank you Generac. Appreciate you all Happy Holidays Merry Christmas. Happy new year to us all.
Date published: 2020-12-03
Rated 5 out of 5 by from Darned Outages We have been subject to power outages about once a month for hours on end-which pushed me to make power of my own. Here in the South in summertime it gets very humid and without air I have a hard time breathing-well no more. Fired right up on 2nd pull of the recoil and ran as it should right from the start. I installed a wall kit to transfer power indoors without exhaust and rain coming in from an extension cord thru the door. This unit will run a 12000BTU air/heat unit and also other electrical items at the same time without barely a complaint. If I had to rebuy I definitely would.
Date published: 2020-11-04
Rated 5 out of 5 by from Fairly quiet for the power you get Bought this unit for camping where we had no power it ran my 13,500 BTU air conditioner no problem. It ran up for a split second then basically went back to idle. Comes with oil just poured it in and gas and gave it a pull.
Date published: 2020-09-10
Rated 5 out of 5 by from Awesome Generator I just purchased this generator because of the size and weight and to run my 13,500 BTU A/C in my pickup camper along with the other items in it and after I got it all full of oil and gas I was taken by the quietness and power. When I turned on the A/C it never fazed it just keep on running as if I had never turned anything on. Its an amazing generator if your in the market..!!
Date published: 2020-06-16
Rated 5 out of 5 by from GP3500io-Nice & Quiet! Just what I was looking for, easy to move around, quieter than I thought it would be,love it!
Date published: 2020-04-29
Rated 4 out of 5 by from More quiet than i imagined Nice size, unbelievably quiet. I have a Genrac Home Standby generator and have had great luck with it so hoping for the same with the portable. I wish 'RV Ready' meant it had a 30A RV plug instead of 30LR5 Twistlock or at least make it an option to eliminate the need for an adapter. Wish there was a wheel kit, cover, & other accessories available for this unit.
Date published: 2020-04-18
Rated 5 out of 5 by from GENERAC IO3500 I purchased this generator a few days ago to use with my travel trailer and it did not disappoint. The A/C unit in my trailer is louder than the generator. I can not hear the generator when the A/C is running. It powers everything in my trailer. Great product.
Date published: 2019-06-17
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GP3500iO is rated 4.9 out of 5 by 10.
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