Congratulations... your MedAngel temperature sensor has arrived! :) It is waterproof, so no refrigerator, cool bag or rainfall can harm it.
This is why 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 open it again to change the battery.
The instructions and videos below will help you open the battery cover and insert the battery.
1. When taking the sensor out of the package for the first time, the battery lid should already be turned to 'open' (two small dots at the back help you check whether the cover is 'open' or 'closed'), but you might have to turn it a bit further to the left with a coin to open in completely. This is best done while the sensor is lying flat on a table. Once it comes out a little, you can pry it open.
2. Once the lid is open, the battery is to be inserted with the plus sign (+) facing upwards.
3. The lid should then be closed by being pressed down in the 'open' position, and then by being turned to 'closed' with a coin, as can be seen below. Once again, this works best when the sensor is lying flat on a table.
4. The surface of the back of the sensor has to be completely flat for it to be closed correctly. Once this is done, the battery compartment is sealed and waterproof.