Q: The data logger loses its time when power is disconnected
A: The battery on the main board is empty or the battery holder contacts are corroded or worn. First measure the battery voltage on the battery holder contacts with a volt meter. It should read 3V. If lower, replace the battery, type CR1632. When the problem persists, remove the battery (it is hooked under the small positive pole contacts) and clean all the contacts carefully. Re-install the battery and check the voltage again.
T: Check the “data logger manual” Chapter 1.1 “Models and Editions” for the Main Board Lay-Out to find the RTC Clock battery location (13). The picture shows the contacts to check with a voltmeter.