Technically, the goal zero unit comprise of a battery with 12vdc to 240v AC inverter.
A 12v battery with 60ah (Power = Voltage x Current) capacity should yield about 720watts-hours.
So if your load or device runs 360w continuous, your setup ideally will run 720 / 360 = 2 hours approx..
That itself depends on the efficiency of the inverter unit for power conversion.
You also need to see what type of batteries are used, and the specs of the inverter unit.
Different battery chemistry will have different voltage holding capacities.
Some like the sealed acid batteries in cars are designed for cranking / voltage surge, so the true capacity before voltage drops to a minimum level will not be ideal for powering equipment on a long term basis. Some batts are designed for deep cycle purpose. eg. marine grade sealed acid battery.
For inverters, there are different types too.
Modified sinewave unit cannot power sensitive equipment as they'll cause a lot of electrical noise.
If you use a modified sinewave inverter with ballast driven lights, there is a high possibility that your inverter will blow the ballast unit.
Pure sine wave inverters are a lot more stable in it's output, but significantly more expensive.
Then you'd also need to look at the power rating of the inverter.
Some are rated to be continuous, and some peak power.
eg. if an inverter is rated to run 300w continuous, you won't be able to start a high-surge device like a fan/blower unit rated at 300w because the initial surge will be a lot higher.
Having said all these in a gist, if you think a petrol genset is a hassle, try having to charge the battery system for hours before field usage.
the weight of a typical 60ah marine deep cycle battery is easily 20+kg. a new model Honda Eu1000i genset only weighs about 12kg.
Petrol is messy, but instantly available. If you go for a 4-stroke engine, you don't need to mix 2T lube.
If you need silent operating, then you have no choice but to go battery options, but if lighting is all you need, it's a better investment to buy LED lighting units that can be powered by V-mount or other options.
I have both Petrol & LPG gensets, and also a huge variety of battery & pure sinewave inverter units in my inventory, and I think they all have different purposes. Ultimately if your purpose is for lighting & filming with small crew setup, go for lightweight & battery capable devices. We kind of standardise all our gears to be v-mount compatible so we don't need to worry about a million type of batteries for a million type of devices.
Hope this helps.
