Realtime software often means "hard real time"[1] which is a constraint where a response is guaranteed within a particular time.

This is a fairly specific area where special real-time deterministic operating systems are used etc.

I think your usage was fine, and the pedantic use of "real time" is dying anyway. There's a whole field of "soft real time" which blends into online, and some parts of the battery control SCADA systems may well be true real time anyway.

[1] https://en.wikipedia.org/wiki/Real-time_computing