Your battery should be properly installed.
When replacing a new battery always make sure the Metal Clip, which holds
the battery in position, is firmly fitted for contact activation.
To confirm this you will see all LED lights scanning around the display.
If after installing a new battery you did not see the LED scanning display, this means that
the battery has not been installed properly, please repeat the installation.

We recommend for the first time use a Jeweller to change the battery,

Do not leave a dead battery in the watch for a long time.
It may cause a malfunction due to leakage and be sure to replace it with a new correct one.