- Open the battery cover of the data logger.
- Use a small flat-head screwdriver to lift the top part of the small plastic cover marked Clock battery (CR1/3N), and slide the cover upward until it comes loose.
- Use the small screwdriver to lift the old clock battery from the battery socket.
- Take the new clock battery and verify the + and - markings of the battery itself and the clock battery socket. Insert the new clock battery in the clock battery socket.
- Replace the clock battery cover.
- Close the battery cover of the data logger. Push the latch down until you hear a click. If the cover does not close easily, push the probe (or extension cable) in and try again.