What are you running that uses 30+ gallons of gasoline per day? Personal AI datacenter? I barely use that much in my car per month.

You should be able to expect at least 4-6kwh per gallon at the generator output. So $25 worth of gas in a 5 gallon can stores 5x the energy of a $2000 battery. The only maintenance I've done on my generator is to drain the fuel lines after use. Maybe change the engine oil once or twice per decade. Apart from that, it runs just as well as 30 years ago when it was new.

True, the gasoline doesn't last that long in storage, but I just use it to fill my car every now and then, and get new gas.