Best smoke alarm 2023: Protect your home and family from £15 | Expert Reviews
GP Lithium 9 V Block Batteries Longlife 9 Volt Lithium Li-MnO2, Pack of 5 9 V Block Lithium, Ideal as a Smoke Alarm Battery, for Fire Detectors, Microphones etc.: Amazon.co.uk: DIY & Tools
5pk Excelltec PP3 9V Battery Heavy Duty | 9V Batteries | Square Battery for Smoke Alarm