Question: what is the difference between 3 volt batteries?
Answer: The CR2032 is 20mm diameter and 3.2mm thick. A CR2025 is 20mm diameter and 2.5mm thick. A CR2016 is 20mm diameter and 1.6mm thick. If you are a consumer, replace the battery with the same one that was originally intended, as the holder was designed to fit either one or the other.