RADO Chronograph_DiaMaster_mini - Manual (Page 10)

Battery
The end of the battery’s life is indicated by the second hand making
4-second jumps. Your watch will continue to run for a few days
but you should have the battery changed as soon as possible by your
Rado retailer.
We recommend that you have the watch tested for water-
resistance at the same time.
Approximate battery life: 2 years.
Renata battery No. 394, 1.55 V.
ø 9.55 mm, H 3.60 mm.