From January 1st, 2022, all new QLD rentals & lease extensions must have photovoltaic smoke alarms hardwired with a battery backup. 9 volt battery models are no longer suitable.
New smoke alarm systems must also be interconnected, meaning if one goes off, they ALL go off.
So, if you have an old smoke alarm system, you'll want to organise your free quote ASAP. There are less than 2 months before the new laws come into effect.