So I bought a couple of these Fire Pro fire alarms (smoke alarms) from Bunnings. I realised I never keep the installation manuals for these things, so In case I needed them later I scanned the manual. It’s the cheapest photoelectric smoke alarm in Bunnings, powered by a standard 9V battery (NOT a 10 year lithium). It was pretty easy to install and just like every other cheap smoke alarm out there.
One thing to note is that is has no hush button. There is a test button, but no hush. I prefer the hush ones in rooms near the kitchen, but this should be fine for a couple of bedrooms.
However if you live in Queensland, you can only use these as a quick fix for your existing home. In the future smoke alarms will need to be interconnected.
Here is the timeline from https://www.qld.gov.au/about/newsroom/smoke-alarm-legislation
To comply with legislation, interconnected photoelectric smoke alarms are required:
From 1 January 2017: in all new dwellings and substantially renovated dwellings (this applies to building applications submitted from 1 January 2017).
From 1 January 2022: in all domestic dwellings leased and sold.
From 1 January 2027: in all other domestic dwellings.
But for now, it’s cheap peace of mind.