 It is possible that the jacket could hold a voltage, but the effects of this would not be visible - if they were, they would be short-lived as the jacket would lose its static energy.
<coherence>  It is possible that the jacket could hold a voltage, but the effects of this would not be visible - if they were, they would be short-lived as the jacket would lose its static energy.
 It is possible that the jacket could hold a voltage, but the effects of this would not be visible — if they were, they would be short-lived as the jacket would lose its static energy.