I replaced my batteries yesterday as they were just over 3v (3.04v) but noticed that the temperature recorded suddenly jumped higher with battery voltage. I handled the unit with my hands very briefly and might be the source of higher recorded temperature but I did not expect such a jump as this was all done outside in the cold. The Dew-point quickly returned to about where it was before changing batteries.
I changed the batteries because I’ve had it in the past that the unit suddenly stop working somewhere around three volts or less. At this point the battery voltage drops rapidly.
Then I noticed the new batteries voltage drop quite a bit after changing them. They are new (purchased a month ago). Maybe they’re not as fresh as I thought and pretty sure the are the real brand as recommended by Weatherflow.
I have noticed that with lower ambient temperatures, the battery voltage will drop and in warmer temperatures the voltage will increase. That I guess is as a result of the chemical nature of batteries and temperature.