The Floating Potential node is used when modeling a metallic electrode at floating potential. It applies a constant voltage on the boundary, such that the total normal electric current density equals to zero. Although locally the current density may vary, the total current entering or leaving the boundary equals zero. The constant boundary voltage implies that the tangential electric field equals zero too. Thus, the boundary will behave as an unconnected perfect conductor (a floating equipotential). This is a good approximation when the conductivity of the electrode is many orders of magnitude larger than that of the surrounding medium.

The Initial value for voltage Vinit input is used to provide the initial value for the internal state variables in the Floating Potential. This input can be useful to provide an initial guess to the nonlinear solver or the initial value in a time-dependent study, when the initial values of the other dependent variables (such as the electric potential) are computed from a separate physics or study. In most cases, the default zero value is appropriate.