This invention relates to a lithium ion multi-cell battery (15) wherein plural lithium ion cells (C.sub.n) are arranged in series. Each cell comprises a positive electrode of manganese/spinal oxide and a negative electrode. A first Zener diode (Z.sub.n 1) and first resistor (R.sub.n 1) are connected in series between the electrodes. By setting the Zener voltage (VZ1) of the first Zener diode (Z.sub.n 1) equal to the cell voltage VL of the responding cell (C.sub.n) when positive electrode crystal phase transport stars in that cell (C.sub.n), the charge amount of each cell is made uniform.