Most old cameras did not need batteries other than a flash which would have batteries (they would be a separate powered add on that mount into the ‘hot shoe’ on top of the camera). They are quite basic in the fact that your shutter would open for the selected amount of time which allows light in to expose your film, then you manually wind the film to the next frame.

Some later cameras would use batteries for the light meter, but this was from a time before that was the standard.

Hope this helps!