Solution
The RTC batteries used in sbRIO controllers are standard coin cell batteries. This means that if a specific model, such as the BR1225 from RAYOVAC, is no longer available in RAYOVAC’s catalog, you can acquire them through other manufacturers or sellers.
To ensure proper functionality, it's important to use the exact same battery model specified for your device. As long as the replacement battery matches the original in terms of specifications (voltage, size, and chemistry), it should work correctly in your sbRIO controller.