GENMAX 10500 Peak Watt Tri Fuel Open Frame Inverter Generator, with ATS, Silent Technology, CO Sensor, Digital Display and 50A, Ideal for Home Backup, Construction Site and RV Camping (GM10500XiT)

I've got about 20 hours on this generator so far - just enough to warrant an oil change next time I use it. Used mainly propane for break-in period. Starts every single time literally within seconds, no hassle, no fuss.. So far I'm thrilled. These are four things that NO other generator on the market right now combines into a single package: 1. >10kW, 2. Tri-fuel, 3. Inverter, 4. Has a remote start and ATS port - it even comes with a cable to hook up to your ATS or home automation system (dry contact). It's not that quiet compared to e.g. a Predator 9500 but honestly, not THAT much louder. Open frame generators are going to do that and it's still quieter than a Champion I'm replacing with it. And it comes with some nice little bonus features, like a magnetic dipstick (usually a $10 addon you always have to buy because who runs a generator without one?) and a waterproof cover! One very small complaint is that nearly every generator I've ever bought has come with the first bottle of oil you need to add. This does not. Make sure you have a quart of 10W30 before you start hooking it up. I highly recommend it and look forward to many years of strong usage with it! If you’re in the fence I hope this review helps you!

After a couple hours of running, it seems like the voltage began to swing up and down causing my lights to flicker and appliances to turn on and off rapidly. (I was using the 14-50 connector to feed my circuit breaker panel through a generator interlock.) This made the generator unusable for my intended purposes during a multi-day power outage in my area. When I contacted support they advised me to remove the front interconnect panel and look for loose connections. When I did this I found the neutral contact on the 14-50 connector had totally fallen out. The retaining screw was in the bottom of the compartment loose as well. Both of these can be seen in the images I attached. Disappointed in my experience and won't buy from genmax in the future.

I have some mixed feelings on this generator. Starting with the good, it successfully kept my all-electric house warm for a week without grid power in the aftermath of the recent ice storm. It started and ran reliably every time for 10 hours a day on propane (until I ran out), 2-year old stabilized non-ethanol gasoline (until I ran out), and fresh E10 (normal pump gasoline). I had this generator feeding into my battery backed whole-home inverter system, so I was able to precisely control how much power I drew from the generator with any surges being < 1 second before the battery charging rate adjusted. This system can automatically start the generator with a two-wire connection, and this generator was the only one I could find that natively supports this control scheme (strong selling point). My home inverter does pass through any distortion from the generator to my loads, and I am pleased to report this generator had no issues with output frequency or clean waveform. I had a different non-inverter generator before that would constantly trip my computer UPS devices - this Genmax unit never does that (excellent). Now for the bad; the power ratings are, unfortunately, lies. Running off gasoline (higher power ratings), would not run at over 7000W continuous without overloading and would not *reliably* run over 6300W continuous +1000W surges without overloading. Starting from no load, the surge capacity is not sufficient for the inverter's own governor to adjust engine speed. Applying a load of 4500W would stall or overload (engine remains running for overload, with no electrical output) before the engine ramped up (it can handle 4500W no sweat if you can bring up the load 1000W at a time). With a heavy surge under the overload threshold, the output can still very noticeably sag. As mentioned before, an inverter overload that does not stall the engine still cuts out the output power - you have to really watch it because if you don't notice that you're no longer getting incoming generator power, it will just sit there happily burning your fuel to idle until you manually hit the reset button. Finally, my unit had the whole front panel broken when I got it (plastic around the 4 mounting bolts broke). I contacted support about this and they said they would get back to me about it within 48 hours, but never did. This is only cosmetic damage, and I've worked around it with zip ties for now, but both the damage and being ghosted by support annoys me. The unit is also super loud, but that's expected and acceptable for an open frame generator.

I recently purchased this generator as all of my current inverter generators are 5000 watts or less. It was important to me to have a unit that was: 1. An inverter so it was fuel efficient, clean power, and quieter 2. A Tri-Fuel generator so I had a lot of options 3. 240v so it could power anything 4. Have a 30 and 50 amp plug 5. Be powerful enough to power my whole electrical panel 6. Include wheels, handle, and cover as well as all accessories. This generator checked ALL the boxes. I added oil, installed the handles and wheels, and hooked up battery and propane. It started right away and was able to power everything I threw at it. I like that it has eco mode and can throttle down. It also has a remote key fob to start from inside your house, electric start with the push of a button, or a recoil start. I have purchased other units before from other manufacturers and I’ve always had to buy the handle and wheel kit, cover, and cables separately - but not with Genmax. It came with everything I needed. I highly recommend it and look forward to many years of strong usage with it! If you’re in the fence I hope this review helps you!

Can only rate 4/5 due to not able to pull FULL rated continuous power on GAS, only about 85%. Still though, I AM generally happy with this generator. I own 2 of these generators, while breaking in these generators, I used them to charge my EV so I could easily vary the load and then to test the limits of what the generators could really provide in wattage. I ran some gasoline as well as propane and at 50% load ran about 1 gallon/hour on gas. At about 85% load on both gas and propane my EV started detecting voltage dropping enough that it limited the charging current to stabilize voltage I could pull a max of roughly 6500 watts on gasoline and about 5800 watts on Propane before my EV detected a voltage drop and dropped the charging amperage. I also note that a 30 gallon propane tank can NOT provide enough sustained vapor to maintain operation at 50% load for more than about an hour. Will test again when I get my new 100lb tanks. I bought 2 of these with the intention to connect them using a parallel kit, however I am waiting to hear back from after resales support to know what parallel kit should work as Genmax doesn’t currently have a parallel kit with cables long enough to connect 2 of these side-by-side.