AbstractThrough computer control, precipitated manganese(II)‐hydroxide and manganese(II)‐hydroxide/aluminum hydroxide are investigated as positive electrodes for secondary cells in aqueous potassium hydroxide solution with regard to charge capacity and cycling behaviour. Pure Mn(OH)2is oxidizable to MnO1.21, the discharge capacityqdlies between 17.2 and 24.0 in mAh/g; ca. 50 cycles are measured during decreasing discharge capacity. Manganese(II)‐hydroxide/aluminum hydroxide takes up comparatively more charge with better Faraday‐efficiency and can reach the oxidation stage MnO1.48. The determined maximal discharge capacityqdwith 121 mAh/g is also much greater than with Mn(OH)2; with decreasing discharge capacity 60–70 cycles are observed. The electrochemical properties are influenced by thepHvalue of the precipitation medium.