Amazon has the X-Sense SD2L0AX smoke detector 3-pack at $9 off the regular price. Each alarm uses a sealed battery rated for up to 10 years, so there are no battery swaps to track. Shipping is free. Buy Now at Amazon
Features
Pack of 3 battery-powered smoke alarms Built-in lithium battery lasts up to 10 years ETL listed and tested to UL 217 safety standard Photoelectric sensor helps reduce cooking false alarms No wiring needed, mounts with included screws Test/silence button & built-in self-test
