... your MedAngel temperature sensor has arrived! :) It is waterproof, so no refrigerator, cool bag or rainfall can harm it.
As a result, the battery compartment is sealed up really well and can be a bit tricky to open - but don't worry, it will be several months before you need to change the battery.
Open the lid
by turning it to 'open' (left) with a coin
When taking the sensor out of the package, the battery lid should be turned to 'open' position, but you may have to turn the lid even a bit further in direction of the 'open' symbol (left). This is best done using a coin and with the sensor flat on a table. It should lift a little, so you can pry it open.
Insert the battery (+) facing up,
close the lid
by first pressing it down in the 'open' position, then turning it to 'closed' with coin
This works best, when the sensor is lying on a table. You can see if the lid is closed correctly when the surface is completely flat. The battery compartment is now sealed and waterproof.