Clock change=Time to upgrade. Amazon has the Kidde Smoke & Carbon Monoxide Detector Sale battery that lasts for the life of the detector for $29.40, Free Shipping with Prime or $25 order. No more chirping in the middle of the night! Rated 4.2 out of 5 stars.

• These are required in California and some other states starting in 2014

• Fire & CO detector in 1 unit with alert modes, LED lights, & voice alarm, that states, "Fire Fire", "Warning Carbon Monoxide", or "Low Battery"
• Ionization sensor technology - smoke detector detects invisible fire particles, 85 decibel alarm alerts of fire at 10 feet
• Protects during a power failure - combo smoke and CO alarm operates on 2-AA batteries
• Test-Hush Feature - silences the unit for approximately 8 minutes; tamper-resistant technology deters removal of the unit from the wall or ceiling
• UL Certified, 10-year limited warranty

• Free 30 day trial to Amazon Prime for Free Two-Day Shipping.
• Students get a free 6 month Amazon Prime Trial