Method and cell monitoring unit for monitoring a battery, central monitoring unit and battery

The method involves measuring parameters of cells (2a-2n) of a battery (1), and synchronously transmitting the parameters to a central monitoring unit (4) using pulse-width modulated signals. The signals are added in the monitoring unit, and steps in the added staircase-shaped signal are interpreted as measured values of the cells in the monitoring unit. The measured values are isolated from the added signal, and a deviation of the parameters of the cells from a reference value of the respective cell is derived as the measured values. An independent claim is also included for a cell monitoring unit comprising a measuring device.