Do I absolutely need to have the battery in a Canonet 28 to use it?

A relative gave me one to lighten his packing load before he moved to another state.

It has some nice aperture settings and if the shutter speed is not controlled singly by the camera's battery, I for the most part, want only want to use it in natural light without a flash; the auto settings seem kind of weak.

I think this would be a much stronger camera if it could be used only in a mechanical fashion without necessity of a battery alone.

It has an old film roll in it right now that it's former owner used, that is why I am not messing about with it too much and not completely familiar with it yet, but I did replace the battery a short time ago.