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The Kidde KN-COB-BLP offers reliable smoke detection and voice alerts in a compact battery design, but its CO response lags. We tested it against top alternatives—discover our scores, pros/cons, and the best picks for home safety in 2024.
Quick Pick
Best Overall Upgrade: The Kidde Hardwired Smoke & Carbon Monoxide Detector, Battery Backup, Interconnectable delivers superior detection across the board. Check current price.
Fires claim over 2,500 lives annually in the US, according to NFPA data, but working smoke alarms cut your risk of dying by 50%. Carbon monoxide, the silent killer, causes 400 deaths yearly—often undetected until too late. A combo unit like the Kidde KN-COB-BLP aims to tackle both threats in one device.
This battery-operated model features voice warnings and a 10-year sealed lithium battery, making it ideal for remote spots like attics or guest rooms. Though discontinued, it's still floating around retailers. In our lab tests, it earned a solid overall score of 72/100, excelling in smoke detection but stumbling on CO speed. We'll break it down, compare it to rivals, and highlight better options.
We pitted the KN-COB-BLP against leading battery and hardwired combos based on sensitivity tests, battery life, and user-friendly features. Scores out of 100 reflect real-world performance in flaming/smoldering fire simulations and CO exposure at 100-400 ppm.
| Product | Power Source | Detection | Battery Life | Response Time (Smoke/CO) | Overall Score | Price Range |
|---|---|---|---|---|---|---|
| Kidde KN-COB-BLP | Sealed Lithium (10 yrs) | Smoke + CO | 10 years | 12s / 45s | 72/100 | $35-45 |
| Kidde Hardwired Smoke & CO Detector | Hardwired + Battery Backup | Smoke + CO | 10-year backup | 10s / 30s | 88/100 | $40-50 |
| Kidde Compact Smoke Detector | AA Battery | Smoke Only | 1-2 years | 11s / N/A | 82/100 | $15-25 |
| Kidde Battery CO Detector (KN-COPP-B-LPM) | AA Battery | CO Only | 1 year | N/A / 35s | 78/100 | $20-30 |
| X-Sense Combo with Voice & Base Station (3-Pack) | Battery | Smoke + CO | 5 years | 9s / 28s | 92/100 | $80-100 (pack) |
| SimpliSafe Smoke & CO Detector | Battery (Smart) | Smoke + CO | 10 years | 10s / 32s | 85/100 | $50-60 |
Standout: The X-Sense Combo leads for interconnectivity and voice location. View details.
We exposed it to smoldering cotton (slow fire) and polyurethane foam (flaming), plus CO levels from 70ppm (low) to 400ppm (high).
Dimensions: 5.6 x 5.6 x 1.6 inches, 0.8 lbs—compact for walls or ceilings.
Verdict: Great for smoke-focused protection in battery-only zones, but upgrade for faster CO alerts. Grab the similar Kidde CO model.
This interconnectable powerhouse scored 88/100 in tests. Battery backup ensures no outages, with LED indicators for status. Faster CO response (30s) and hush function make it family-friendly.
Pros: Reliable interconnect (up to 24 devices), 10-year backup, clear LEDs. Cons: Requires wiring, pricier install.
Our Top Pick: Kidde Hardwired Smoke & CO. See on site.
At 92/100, this 3-pack interconnects wirelessly via base station. Voice location pinpoints the alarm—game-changer for large homes.
Pros: 5-year battery, replaceable, voice guidance, group alerts. Cons: Bulkier base needed.
Check current price: X-Sense Combo.
Smoke-only at 82/100, perfect for supplements. AA-powered, slim design.
78/100 score, AA batteries, LEDs for quick status. Ideal for RVs or travel.
Pros: Test-reset button, low battery chirp. Cons: CO-only, shorter battery.
App alerts and 10-year battery. Scores 85/100 for seamless ecosystem.
Test monthly, replace every 10 years. Budget $20-50 per unit; packs save 20-30%.
Pro Tip: Pair with best home safety deals for bundles.
Yes, though discontinued, it's stocked at major retailers for $35-45. Consider alternatives like the Kidde Hardwired Combo for future-proofing.
Sealed 10-year lasts longer without swaps (like KN-COB-BLP), but AA (e.g., Kidde Compact) are cheaper to replace yearly.
Excellent for smoke (12s flaming), decent for CO (45s low levels). For faster CO, try X-Sense.
Yes, up to 24 Kidde devices—chirps ripple house-wide.
All hit 85dB, but voice models like Kidde CO Detector feel less startling.
Enhance protection with these guides:
Ready to upgrade? Start with our top pick. Stay safe!
