How long does the battery last?
The battery life indicated on the data sheet is calculated on the normal consumption of the logger and should be taken as a rough indication. The consumption of the batteries obviously depends on the use made of the instrument and above all on the acquisition rate set and on the temperature of use: the higher or lower it is, the higher the consumption will be.
Furthermore, lithium batteries do not have a depletion curve like alkalines but they maintain more or less their nominal voltage almost to exhaustion and then suddenly collapse.
Another caveat is that if you connect the loggers that are still very hot or very cold you could read low battery voltages but once they return to room temperature the readings will also return to normal.