Health & Wellness · Head-to-head
Kidde KN-COP-DP-10YL Worry-Free Plug-in CO Alarm vs First Alert CO710 Carbon Monoxide Alarm with 10-Year Battery
Which should you buy? Our verdict on both, pulled from our full The Best Carbon Monoxide Detectors: 4 Compared (and One to Skip) comparison.
The Kidde wins because it removes both failure modes at once: no battery to forget, and a display that survives a blackout when more than 100 ppm is present. The First Alert CO710 gets you a sealed 10 year battery with no wiring and a ppm and peak readout, as long as a tabletop or shelf is the right home for it.
Kidde KN-COP-DP-10YL Worry-Free Plug-in CO Alarm
Buy itA plug-in alarm with a sealed 10 year lithium backup and an LED ppm readout, backed by a full published spec sheet.
- Kidde's data sheet states an electrochemical fuel cell sensor, 85 dB at 10 feet, a 10 year limited warranty, and listing by UL to the UL 2034 standard.
- The sealed lithium backup keeps it running through a power cut and cannot be borrowed for the TV remote.
- A peak level button recalls the highest CO concentration recorded since the last reset, which Kidde notes is useful for medical responders.
- The display shows nothing until CO reaches 30 ppm, which is a UL 2034 rule rather than a Kidde choice, so a blank screen is not evidence of clean air.
- Kidde specifies display accuracy of plus or minus 30 percent, so read the number as a magnitude rather than a measurement.
- The display switches off when AC power is removed unless more than 100 ppm is detected or the unit is alarming.
First Alert CO710 Carbon Monoxide Alarm with 10-Year Battery
Buy itA tabletop alarm with a sealed 10 year lithium battery and a backlit display that shows CO in ppm, a recent peak and the room temperature.
- First Alert's spec table lists an electrochemical sensor, 85 dB at 10 feet, a 10 year limited warranty, and listing to the UL 2034 standard.
- The built-in 10 year lithium battery is listed as not replaceable, so there are no battery changes or low battery chirps over the life of the alarm, and an end of life warning tells you when to replace it.
- First Alert says the display can show current CO concentration and recent peak levels in ppm, and that the stored peak can help emergency or hospital staff.
- First Alert describes it as intended to sit on a tabletop or shelf with no installation, so it is not the alarm to fix to a hallway wall.
- The product page lists an end of life warning but does not describe the signal pattern, so keep the manual.
- Interconnection is not listed on the product page, so plan on it warning only the room it is in.
Side by side
The 8 criteria below are the ones our full comparison judged every product on, narrowed to these two.
| Kidde KN-COP-DP-10YL Worry-Free Plug-in CO Alarm Our pick | First Alert CO710 Carbon Monoxide Alarm with 10-Year Battery | |
|---|---|---|
| Our verdict | Buy | Buy |
| Best for | Someone who wants one alarm per level, permanently powered, that they never have to maintain or think about again. | Renters, dorm rooms, and anyone adding a bedside alarm on a nightstand or shelf without wiring or drilling anything. |
| Price tier | $$ · mid-range | $ · budget |
| Power | Plug-in, sealed 10 year lithium backup | Sealed 10 year lithium battery, not replaceable |
| Digital display | LED, ppm plus peak level | Backlit, ppm plus recent peak, temperature |
| Sensor | Electrochemical fuel cell | Electrochemical |
| Stated alarm life | 10 years | 10 year battery life, end of life warning listed |
| End of life signal | Beep every 30 seconds, display reads END or ERR | End of life warning listed, pattern not on the product page |
| Listing | UL listed to UL 2034 | Listed to UL 2034 |
| Loudness | 85 dB at 10 ft | 85 dB at 10 ft |
| Warranty | 10 year limited | 10 year limited |
Which one is right for you?
Pick the Kidde KN-COP-DP-10YL Worry-Free Plug-in CO Alarm if
someone who wants one alarm per level, permanently powered, that they never have to maintain or think about again.
Know before buying: the display shows nothing until CO reaches 30 ppm, which is a UL 2034 rule rather than a Kidde choice, so a blank screen is not evidence of clean air.
Pick the First Alert CO710 Carbon Monoxide Alarm with 10-Year Battery if
renters, dorm rooms, and anyone adding a bedside alarm on a nightstand or shelf without wiring or drilling anything.
Know before buying: first Alert describes it as intended to sit on a tabletop or shelf with no installation, so it is not the alarm to fix to a hallway wall.
The bottom line
Our overall pick is the Kidde KN-COP-DP-10YL Worry-Free Plug-in CO Alarm - A plug-in alarm with a sealed 10 year lithium backup and an LED ppm readout, backed by a full published spec sheet. Choose the First Alert CO710 Carbon Monoxide Alarm with 10-Year Battery instead if renters, dorm rooms, and anyone adding a bedside alarm on a nightstand or shelf without wiring or drilling anything.
Want the full picture, including the other options we compared and the popular one we'd skip? Read the complete The Best Carbon Monoxide Detectors: 4 Compared (and One to Skip).