Do not put initial charge, just change the voltaje over time

src/modules/mesh/moduleMesh@boundaryEM.f90

@@ -159,7 +159,7 @@ submodule(moduleMesh) boundaryEM
         ! Inverse of non-dimensional capacitance
         self%invC = 1.0d0 / (capacitance / (eps_0 * L_ref))
 
-        self%charge = self%potential / self%invC
+        self%charge = 0.0d0
 
         self%update => updateFloating
 
@@ -200,7 +200,7 @@ submodule(moduleMesh) boundaryEM
       class(meshEdge), pointer:: edge
       real(8), allocatable:: mom_nodes(:)
       class(meshNode), pointer:: node
-      real(8):: mom_center, edgeDensityCurrent
+      real(8):: mom_center, edgeDensityCurrent, chargeTau
 
       select type(self)
       type is(boundaryEMFloating)
@@ -230,12 +230,14 @@ submodule(moduleMesh) boundaryEM
 
           end do
 
+          chargeTau = edgeDensityCurrent * edge%surface * tauMin
+
           ! Accumulate charge of speceis on surface
-          self%charge = self%charge + edgeDensityCurrent * edge%surface * tauMin
+          self%charge = self%charge + chargeTau
 
         end do
 
-        self%potential = self%charge * self%invC
+        self%potential = self%potential + chargeTau * self%invC
 
       end select