When constructing a new smart battery (or selecting a battery for the first time after loading a game), the texts for the sliders read "Break starts at" and "Break ends at" instead of "Standby" and "Active":
It reverts to "Standby" and "Active" after deselecting and reselecting the battery:
Steps to Reproduce
Start a new game. Construct a smart battery. Select battery. - or - Load a game with a smart battery. Select battery.
This issue has not been confirmed by a developer yet.