New alarms hu? Hum... how long should fire alarms ben used? I think mine are going on 6 yrs now.
Better yet, bring you home up to current building code. Hardwire these into your home. Mine are so loud they will wake the dead, potentially starting a Zombie apocalypse if they ever go off near a dead body.
If you want more, then have your secondary alarms tied into you alarm system and have it trip your internal siren.