Is there a way to give a two-pronged plug power from a battery?

Dear forum folks:

I am someone with only the most basic electronic knowledge. I am working on a project with string lights which need to be portable. For this reason, I am unable to power these lights in the conventional manner (ie extension cord). I am wondering if there is a way to power the string lights, which have a two-pronged plug, through a battery of some kind. Is there an adapter for two-pronged plugs which uses batteries, for instance? Any advice would be appreciated. Many thanks.

I know they make DC > AC converters. I looked at getting one for a robot I wanted to make one time that involved an indistrial PLC machine self contained inside the robot.

They do make them though, I think they run off of 12V batteries, and some can output well above the average wall outlet.

They are called 'inverters' and very common. There are even portable power pack with a battery built in. What sort of lights, and how many watts do you need to power? Maybe I can help you find something.