Smoke Detector inside the room of a condo - Doesn't blink, should it?

[bbi1]

In a previous condo building I lived in, the smoke detector inside the room flashed red every so often, maybe around 30 seconds to a minute each flash.

 

I am now living in a different condo building. The smoke detectors inside my room of this condo building doesn't blink at all. I thought that smoke detectors should periodically have a flashing red LED light that blinks every minute to show that it's working and that there's still battery in it. I asked my real estate agent when I moved in, who's also a foreigner, but he had no clue. The Thai owner of the room said he thinks all the smoke detectors in the rooms should be hard-wired and doesn't think there's a battery in each. I asked the juristic office and they also had no clue.

 

Anyone here experts in smoke detectors know what could be the correct answer?

[scubascuba3]

Usually there is a button on it, press and test it. Maybe connected to mains or battery only. Take a photo of it and do an image search