Yes, you are a little unclear when you say *battery potential.* But I think I know what you mean, so let me try to explain it.

Inside the battery there is a process going on which *forces* the electrons (or any other negatively charged species) to one side and the positively charged things to the other side. A very simple battery does this by redox reaction. Since, now we have oppositely charged species separated by a distance therefore there develops an **Electric Field **going from positive side to negative side.

The definition of the potential says "*amount of work done to move a unit charge from one place to another"* , in mathematical terms we can write it as \(\displaystyle \int_{a}^{b} \mathbf{E} \cdot d\mathbf{dl}\) . Since, we have understood how the electric field was created, so from there it follows that a potential has been created.

As far as analogy with gravity is concerned, you can view it as charged things have tendency to *FALL* from positive side to negative side, due to lower potential on the negative side.