I would say about 70 hours but that depends on how big your generator is and how much you are running off of it. A moderate load like 1000 watts will not be much different than a light load but if you plug everything in the house, air conditioner, hair dryer, toaster, into it, it will consume more fuel. Best thing to do is keep a close eye on your gage. If you have a propane bbq grill with any fuel, you can also use the smaller tank from it.
backhoe, I saw your trick for dead batteries using the Epsom salts, That one is safe but if you got nothing at all after 30 minutes of charging, your marine batteries are most likely not going to respond and not worth wasting your limited fuel on. The only way to bring back a battery like that is not very safe. This method involves reverse charging the battery, back and forth, several times. It can generate sparks and lots of hydrogen gas, not a good combination and not recommended.
Hmmmm... is there any way to use a generator to charge the marine batteries?
If your tractor battery is any good and your if generator has an electric start, you can charge a battery by connecting jumper cables to the generator battery terminals.
While there are some major lines down, I read that a whole lot of trucks and crews are on their way so hopefully it won't be that long. Good luck and I hope you win at least a few board games.
Thanks for clarifing that- it's been so many years I was not sure.
With the roads blocked, getting the main tank refilled looks like it's a problem-- around here, all the hardware and building supply stores have racks of Bar-B-Q sized cylinders- "Blue Rhino" is the local brand. That might be one way to keep the powerplant running in a pinch. Granted, finding any would be one problem, and transporting them yet another to be solved.
The only way to bring back a battery like that is not very safe. This method involves reverse charging the battery, back and forth, several times. It can generate sparks and lots of hydrogen gas, not a good combination and not recommended.
That old trick had slipped my mind- you are certainly right about the potential hazards. If you do it, move everything out into the open air, make sure the connections to the battery are tight ( to minimize sparking ) and be sure to kill the power at the source before disturbing the connections. Hopefully, it won't come to that- it's better avoided.