How to create an electrical charge from a wire in water, with a battery charger and/or battery?

Create an electrical charge? I think you meant 'make a current flow' in water from a wire and a battery.

What do you need for a current to flow? Either delocalised electrons or charge carriers, for example moveable ions. Water consisting of covalent molecules (therefore no delocalised electrons) hardly dissociates to form ions.

Therefore, moveable ions are to be introduced in the system. A small amount of an acid would do that very well, such as dilute sulphuric (or sulfuric) acid works great!