On interior boundaries, the Surface Charge Accumulation node implements the boundary condition

where ρs is the solution of the following distributed ODE on the boundary:

where n · Ji is the normal component of the total ion current density on the wall and n · Je is the normal component of the total electron current density on the wall.

Enter the values or expressions for the Normal ion current density n · Ji (SI unit: A/m2) and the Normal electron current density n · Je (SI unit: A/m2).