On 18/03/2018 21:24, alan_m wrote:
In addition, there will be a 10-year age limit for alarms and all
alarms will have to be ceiling-mounted, and should be
interlinked.".........

As they have to be interlinked do they also have to be mains powered?

I dont know, I am only asking as I am writing to my MP asking how he
expects those that can ill afford to pay for the installation.