What is a good portable power supply for a pc?

I have a Mac mini and a monitor, along with an iphone and speakers, what would be a good power generator/rechargeable box that has 4 female ends for wall outlets. I need something like this for trips

Possibly a power inverter can be installed in your car/truck/whatever, but I think they only come with two, but you can probably use a power strip to give you more than enough outlets.
Downside: They can't leave your vehicle. (because they get the power from your car battery)

Another option is a generator. They can be moved anywhere! The same (possible) 2 outlet problem again, can be fixed with a power strip.
Downside: They require gasoline, they are noisy, and they are big and bulky.

I could very well be incorrect about a few things, here, I suggest you do a bit of research yourself.

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