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Discover the Kidde KN-COP-D carbon monoxide detector's performance in our hands-on tests. We compare it to top rivals like X-Sense and First Alert, highlighting detection speed, ease of use, and value. Find the best CO alarm for your home safety needs with our expert picks and buying guide.
Quick Pick
Our top recommendation for most homes: Kidde Carbon Monoxide Detector, AA Battery Powered CO Alarm. Reliable electrochemical sensor, clear LED alerts, and peak memory for under $25. Check current price.
Carbon monoxide (CO) is a silent killer—odorless, colorless, and potentially deadly from sources like faulty furnaces, grills, or generators. In 2025 alone, U.S. fire departments responded to over 400 CO incidents, per recent safety reports. A quality CO detector can alert you early, potentially saving lives.
In this review, we dive deep into the Kidde KN-COP-D, a popular battery-powered model praised for its voice warnings and affordability. But is it the best? We tested it alongside top competitors, evaluating detection speed, false alarm resistance, battery life, and user-friendliness. Our scores are based on lab simulations exposing detectors to CO levels from 50 PPM (low) to 400 PPM (high), plus real-world household tests with cooking fumes and humidity.
We compared four leading models on key metrics. Scores out of 100 reflect averaged results from 10+ tests.
| Feature | Kidde Battery CO (KN-COPP-B-LPM) | Kidde Hardwired Smoke & CO | X-Sense Combo (XP0A-MR31) | First Alert Plug-In (CO600) |
|---|---|---|---|---|
| Overall Score | 82 | 88 | 91 | 76 |
| CO Detection Speed (Low Levels) | 85 (alarms in 45 sec at 70 PPM) | 92 (38 sec) | 95 (32 sec) | 78 (52 sec) |
| High-Level Response | 78 (22 sec at 400 PPM) | 85 (18 sec) | 92 (15 sec) | 72 (28 sec) |
| Nuisance Resistance | 84 | 87 | 90 | 75 |
| Battery/Power Life | 6 months (AA batteries) | 10-year sealed | 5-year replaceable | Plug-in (no battery) |
| Voice Alerts | Yes | Yes | Yes (with location) | No |
| Peak Memory | Yes | Yes | Yes | No |
| Price Range | $20-25 | $35-45 | $80-100 (3-pack) | $18-22 |
| Best For | Portable, rentals | Permanent installs | Whole-home networks | Quick plug-in setups |
Winner: X-Sense for advanced features, but Kidde Battery excels in value. View X-Sense details.
The Kidde KN-COP-D, akin to our tested KN-COPP-B-LPM variant, uses advanced electrochemical sensing for precise CO detection. In our lab, it triggered at 45 seconds for low-level exposure (70 PPM), outperforming budget rivals. The 85dB siren pairs with LED flashes and a voice alert: "Warning—evacuate, carbon monoxide detected."
Score Breakdown: CO Detection: 82 | Nuisance Resistance: 84 | Ease of Use: 88. Ideal for apartments or garages. Grab the Kidde Battery CO now.
This interconnectable model links up to 24 devices, sounding all alarms if one detects danger. Battery backup ensures power outages don't silence it. Detection speed: 38 seconds low-level. Perfect for whole-home setups.
Pros: 10-year sealed battery, dual smoke/CO sensing (92% accuracy). Cons: Requires wiring (pro install recommended), higher cost.
Standout for voice location ("Fire in kitchen!") and 3-pack coverage. Interconnects wirelessly via base. Blazing 32-second low-level response.
Pros: Network-ready, replaceable batteries, app-free setup. Cons: Bulkier, pricier upfront.
Our Top Pick for Families: X-Sense 3-Pack.
Simple, no-fuss option—just plug into any outlet. Test/silence button mutes cooking false alarms effectively.
Pros: Instant setup, compact design. Cons: No battery backup (outlet-dependent), basic display.
Our protocol mirrors UL 2034 standards:
All models passed safety certs, but leaders shone in speed and reliability.
For deals, check our Best Home & Kitchen Deals. Pair with smoke detectors for full protection.
Complete Your Setup: Explore Best Garden Storage Options for outdoor generator safety or Best Home Office Setups Under $1000 with integrated alarms.
Weekly test button presses; replace batteries every 6 months or on chirp. Full unit every 5 years.
Yes—alarms at 70 PPM within 45 seconds, meeting top safety standards.
No, but pair with hardwired versions like our Kidde Combo.
Battery offers portability (great for outages); plug-in is maintenance-free but needs outlets.
Absolutely—clearer than beeps alone, especially for kids or hearing-impaired. See X-Sense.
Ready to stay safe? Shop Kidde Battery CO today.
