Can you replace CR2025 with CR1620?

No, you cannot replace a CR2025 battery with a CR1620 battery. The CR2025 is thicker (2.5 mm) than the CR1620 (2.0 mm), which means the CR1620 may not fit securely in devices designed for the CR2025. Additionally, the CR2025 typically has a higher capacity, providing longer battery life, so using the thinner battery may result in reduced performance or shorter usage time.