High differential charging is known to occur on geostationary satellites between two electrically isolated pieces of the same material. This happens because current balance with the ambient space environment on each surface can be satisfied by different surface potentials. Three such potentials (two stable and one unstable) are found for the two-Maxwellian plasmas considered in this study and in the absence of photoelectron emission. Thus two isolated surfaces can have significantly different potentials leading, possibly, to electrostatic discharges. It is shown that in an electrostatically noisy environment, one of the surface potentials is more likely to occur than the others and thus both surfaces will achieve this most probable potential independent of their previous charging history. The time for this to happen, while dependent on the characteristics of the roots, can be relatively short and may limit this type of differential charging. This effect is examined in quantitative detail for the environments measured by the ATS-5 and SCATHA satellites.