Generator Battery Dead! Will it still Run? 

I think what is going on on most of the tests is that if you start the generator with a little bit of gas in the carb, then it produces just enough power to energize the electric solenoid that permits propane flow. After that, it continues to run on propane. So I think if you started with dry gasoline tanks, the results would be different.

This is a great test. Great info...thanks.

I own the 7250 running on propane. Had starting issues. Just cracked the valves opened on both of Tank and generator side And see if it will start. If does not start adjust until it does.

This is exactly why I run my gensets twice a month. If the battery gets weak, you'll know it hopefully in time to replace before it's really needed. As always, great video and love the topic!

My Champion 3500 watt duo fuel will start on propane but not gas with a dead battery. It needs power to open a solenoid for gas to flow. It covers in in the owners manual.

Thank you for the video. One issue that you didn't address, at least in this video, is: Does a generator without a battery actually produce an AC output? Under what circumstances might or might it not produce an AC output? What if there isn't enough residual magnetism in the rotor to self-excite?

Great Video!

Thanks Johnny, that's a really valuable test. I am fairly sure all the single cylinder standard gasoline only generators will run without the battery unless they are fuel injected. I think all of the V-twin generators need battery power to run the ignition. The designers of those generators that won't run without battery power obviously don't understand necessary critical operation when the generator is used for backup emergency power. If you are serious about maintaining your backup power, you will run your generator periodically to exercise it and and make sure it is performing properly. However, the average person doesn't think about the generator until the power is out. I can't speak for the Lithium batteries the generators are starting to come with now but, the sealed lead-acid batteries typically last 1 - 2 years if left in the generator, which is generally stored in a room with an uncontrolled temperature. I have had so much trouble with these batteries dying, that I only install the battery in the unit when I actually use it. When not being used, I keep the battery in a controlled environment and charge it every 2 months, which extends the battery life to at least 5 years. Mounting any battery inside one of these soundproofed generators results in a brutal operating environment for the battery, with the heat being the number one problem. This holds true for the Lithium batteries as well as the lead-acid, the battery should never be exposed to temperatures over 90F/32C. If the battery is mounted properly, it will be in front of the air intake for the inverter circuit. My concern with the use of lithium-ion batteries in these generators is, if overheated, they could catch on fire (a fire that is self-sustaining) but, time will tell.

Catch 22 with an electric fuel valve: Without electrical power, the fuel valve won't open. Without fuel, it won't start. Heavy cranking might just generate enough electrical power to open the fuel valve. Energy to open the valve could be different for fuel types. Also, it could depend if the generator was just running previously. There could be just a minute amount of fuel remaining in the carburetor jet. There may still be some propane in the hose going to the carburetor. A manual valving could make it start reliably.

Great video, Genmax has a diverse line of products, I wish they were available in Canada.

What would happen with a battery connected with let's say 10ish volts? Not enough to start it but some signal reference? 👍

My question is, can you switch it from gas to propane while the generator is running?

I need a new battery for my genmax 5500i. does it take a special battery? does it hurt anything to run them with no battery?

Do you recommend a battery charger/maintainer like a NOCO? If so, which one? I've been thinking about this for a while

Champion makes a duel fuel open frame inverter pull start only generator. I'm thinking of buying it for a backup for 3 regular gas generators. Like the duel fuel option, the model# is 200978. Anyone out there had any experience with it...

I wonder if a dead battery has to be disconnected for the generator to run without it. I have the Maxpeedingrods dual fuel generator, which started fine about 2 months ago. I left the battery connected, no trickle charge, and when I went to start it today, on propane, it wouldn’t start with the start button. And wouldn’t start with the recoil either…..????

I have the 3500 brand new out of box starts on both gas and propane runs for a few seconds the dies any ideas

Great videos. Could Generator be plugged into trailer battery if Gen battery is dead?

Good chance a backup generator will have a dead battery.

I have the Genmax 9000 IEDC with 10 hours in the clock. It was stored drained or gas on the tank and carb. The battery reads 12.5 volts but will not crank up to start. I tried to start it on gas as well and it won't. May I ask for suggestion? I called genmax and was told to bring it to a repair shop at my cost.

Interesting because the battery of my GM3500iED died and I can not start the generator without the battery. Lucky me I have a 2nd GM3500iED and I use that battery for now.

what I want to know is where you got that propane regulator for the genmax 3500. I can tell it's not the original one and I was wondering if your original one they sent with the generator failed in your case also. Mine failed with less than 5 hours on it and 1 year old. Very disappointed in genmax , I don't even know if I want to buy a replacement from them.

Wow you have a lot

Where to get the Battery for the dual fuel genmax? Seems to be a plastic cartridge which can’t be opened that contains the cells. Its printed with 1.6Ah / 12.8 V but I can’t find any spare part battery for that machine. Someone found them?

My battery wasn't dead...it was wired wrong at the plug from the factory.

I use my jump starter to start my generator when the generator battery is dead

Good video, thank you, but a comment on language. In Usian, you refer to "gas" meaning gasoline, whereas in English we call this "petrol". Then you are stuck with what to call the propane. It's actually a real gas, and we would call it "gas" in English. In USian, you need to be very specific about what sort of gas it is. So, you need to specify Hydrogen, methane, ethane, propane, butane. In English, all of those would be gas. 😄

My Champion will run on propane with dead battery.

See just like cars and motorcycles becoming more complicated taking kickstarts of the motorcycles generators are becoming that way too. There was nothing wrong with old made in Japan Yamaha and Honda that had a pull start only and started every time. Society is stupid

Genmax now out of business