First Alert CO605 Plug-In Carbon Monoxide Alarm with Battery Backup
A basic, budget-friendly plug-in CO alarm with battery backup. It sounds when it should but shows you nothing in between.
Updated
- Plug-in with battery backup for power outages
- Low-battery light and chirp, plus an end-of-life signal
- Front test button
- No display and no CO level readout
- The Amazon listing also uses the name CO606
Best For / Not For
Best for
- Adding an alarm to every level or sleeping area on a tight budget
- A backup alarm next to a display model elsewhere in the house
Not for
- Anyone who wants to see CO levels or check a past peak
- Buyers who don't want to change backup batteries
Key Details
What You Give Up Without a Display
A CO alarm's main job is to sound at dangerous levels, and the CO605 does that. What you lose is information. A display model shows a low but rising level, and a peak memory tells you whether CO rose while you were away. With the CO605 the first sign of trouble is the alarm itself.
Battery Upkeep
The backup battery is replaceable, and First Alert recommends testing the alarm regularly with the front button and changing the batteries at least twice a year. Put it on the same schedule as your smoke alarm checks.
Pros and Cons
Pros
- Budget-friendly way to cover more rooms
- Battery backup keeps it working during outages
- Low-battery and end-of-life warnings
Cons
- No display, so low CO that stays under the alarm level is invisible to you
- Replaceable backup battery; First Alert recommends changing it at least twice a year
- Listings differ on the backup battery type between variants, so check the package
Bottom Line
Consider the First Alert CO605 if the goal is to put a working CO alarm in more rooms on a budget. It covers the basics, but for the main alarm near bedrooms a display model like the Kidde KN-COP-DP-10YL tells you much more.
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