A quartz movement is powered by a battery. Its regulator (time measuring device) is a quartz crystal. An electrical current causes the crystal to vibrate consistently and at a very high frequency (32,768 times per second). This gives the movement almost perfect precision (a variation of only a few seconds per month).
The quartz movements used by TAG Heuer are among the most reliable and accurate made anywhere in Switzerland. They are also distinguished by their excellent resistance to shocks and magnetic fields.
The batteries for TAG Heuer quartz movements have a service life of at least two years.
For increased security, all TAG Heuer quartz watches (except chronographs) are fitted with an end of battery life indicator (EOL). When the battery shows signs of weakening, the second hand starts making four-second jumps every four seconds. However, the movement continues to display the exact time until the battery is exhausted.