An apparatus, for providing electrical power, comprising: an electrode assembly (300,700,800,1100) having a positive electrode, a negative electrode, a layer of electrolyte between the positive electrode and the negative electrode, a positive tab (310, 804, 1102) electrically connected to the positive electrode, and a negative tab (312, 806, 1104) electrically connected to the negative electrode, and configured so that an electric current flows through the positive electrode in a first pattern and flows through the negative electrode in a second pattern that is unmatched to the first pattern, resulting in unmatched electric current in a section of the electrode assembly; and a magnetic compensation (420, 820, 1100) structure adjacent to the electrode assembly (300,700,800,1100) and comprising a body of conductive (422, 822, 1122), material, a first compensation conductor (424, 834, 1134) electrically connected to the body, and a second compensation conductor (426, 826, 1136) electrically connected to the body with one of the first compensation conductor (424, 834, 1134) and the second compensation conductor (425, 836, 1136) electrically connected to one of the positive tab (310, 804, 1102) and the negative tab (312, 806, 1104), the magnetic compensation structure (420, 820, 1110) configured so that electric current flowing through the body matches the unmatched electric current in the section of the electrode assembly; characterized in that the positive electrode has a first surface with a first edge and a second edge, the negative electrode has a second surface with a third edge and a fourth edge; and the electrode assembly further comprises a positive tab (310, 804, 1102) electrically connected across the first surface of the positive electrode from the first edge to the second edge, and a negative tab (312, 806, 1104) electrically connected across the second surface from the third edge to the fourth edge; and the magnetic compensation structure (420, 820, 1100) further comprises a first compensation conductor (424, 834, 1134) electrically connected to the body and entirely overlying the positive tab (310, 804, 1102) of the electrode assembly; and a second compensation conductor (426, 826, 1136) electrically connected to the body and entirely overlying the negative (312, 806, 1104) tab of the electrode assembly. an electrode assembly (300,700,800,1100) having a positive electrode, a negative electrode, a layer of electrolyte between the positive electrode and the negative electrode, a positive tab (310, 804, 1102) electrically connected to the positive electrode, and a negative tab (312, 806, 1104) electrically connected to the negative electrode, and configured so that an electric current flows through the positive electrode in a first pattern and flows through the negative electrode in a second pattern that is unmatched to the first pattern, resulting in unmatched electric current in a section of the electrode assembly; and a magnetic compensation (420, 820, 1100) structure adjacent to the electrode assembly (300,700,800,1100) and comprising a body of conductive (422, 822, 1122), material, a first compensation conductor (424, 834, 1134) electrically connected to the body, and a second compensation conductor (426, 826, 1136) electrically connected to the body with one of the first compensation conductor (424, 834, 1134) and the second compensation conductor (425, 836, 1136) electrically connected to one of the positive tab (310, 804, 1102) and the negative tab (312, 806, 1104), the magnetic compensation structure (420, 820, 1110) configured so that electric current flowing through the body matches the unmatched electric current in the section of the electrode assembly; characterized in that the positive electrode has a first surface with a first edge and a second edge, the negative electrode has a second surface with a third edge and a fourth edge; and the electrode assembly further comprises a positive tab (310, 804, 1102) electrically connected across the first surface of the positive electrode from the first edge to the second edge, and a negative tab (312, 806, 1104) electrically connected across the second surface from the third edge to the fourth edge; and the magnetic compensation structure (420, 820, 1100) further comprises a first compensation conductor (424, 834, 1134) electrically connected to the body and entirely overlying the positive tab (310, 804, 1102) of the electrode assembly; and a second compensation conductor (426, 826, 1136) electrically connected to the body and entirely overlying the negative (312, 806, 1104) tab of the electrode assembly.