Just so I understand, 0mV is when there is either a lack of permeability to an ion, no movement, or that ion is balanced concentration gradient. The resting membrane potential (Vm-Eion) happens by diffusion and electric force, which to Nernst (EP) and Goldman Weighted relative permeability. So this doesn't really require ATP, as the pumps, so those are never 0mV because there is movement. Only those ions that are balanced or where there is a lack of permeability can be at 0mV.