A method for determining a state of charge of at least one battery cell, having the following steps to enable an improved determination of the state of charge of a lithium iron phosphate cell: generating an alternating current pulse in a circuit connected to the at least one battery cell, determining an impedance of the at least one battery cell on the basis of the alternating current pulse and determining the state of charge by comparing the impedance to predefined map data, wherein a relationship between the impedance and the state of charge of the at least one battery cell is determined from the predefined map data.