A voltage detecting apparatus for a combination battery includes a multiplexer type flying capacitor voltage detecting circuit, a synchronous control type A/D converter, and a battery controller. The battery controller has a timing table to regulate generation timings of a switching control signal, an activation signal, and a transfer command signal on a common time axis. The timing control is carried out by outputting the switching control signal, the activation signal, and the transfer command signal to the flying capacitor voltage detecting circuit, the A/D converter, and the battery controller at the timing regulated in the timing table and according to an order memorized in the timing table.