Product Reviews

Verdict: 3.9/5. The First Alert CO600 is an AC-only plug-in CO alarm with NO battery backup — it stops working during power outages when CO risk from generators is highest. Appropriate only for commercial settings with guaranteed backup power. UL 2034 listed.

Verdict: 4.1/5. The First Alert CO606 is the budget plug-in CO alarm with 9V battery backup for power outage protection. No display, no interconnect. Always choose over the CO600 (no backup). UL 2034 listed, 7-year warranty.

Verdict: 4.3/5. The First Alert CO615 plug-in CO alarm features a 6-foot power cord for flexible placement, 2 AA battery backup, and a backlit digital PPM display. Best plug-in CO alarm in the First Alert lineup for standalone use. UL 2034 listed.

Verdict: 4.2/5. The Kidde KN-COPP-3 is a plug-in CO alarm with battery backup, digital display, and peak level memory for diagnosing intermittent CO events. Compare with COPD at purchase — COPD adds rotating plug and surge protection.

Verdict: 4.3/5. The Kidde KN-COB-DP2 is the correct residential upgrade over the AC-only KN-COB-DP-LS — 9V battery backup maintains CO detection during outages. Digital display, peak memory, UL 2034 listed.

Verdict: 4.1/5. The Kidde KN-COB-LCB-A is a plug-in CO alarm with digital display and end-of-life notification — no battery backup. Best for commercial, office, and institutional spaces on reliable circuits. For residential use, choose the KN-COB-DP2 or COPD.

Verdict: 4.0/5. The Kidde Nighthawk KN-COB-DP-LS is a plug-in CO alarm with digital display but no battery backup — suitable for commercial and rental use on always-powered circuits. For residential use, choose the KN-COB-DP2 or COPD for outage protection.

Verdict: 4.2/5. The Kidde COP is a compact AC plug-in CO alarm with AA battery backup, rotating plug, and surge protection — no digital display. Budget-friendly plug-in option; step up to COPD for a display at modest extra cost.

Verdict: 4.3/5. The Kidde COPD is a solid AC plug-in CO alarm with AA battery backup, digital display, rotating plug, surge protection, and night chirp suppression — a practical upgrade to the classic plug-in CO alarm form factor.

Verdict: 4.3/5. The Kidde KN-COPP-B is the best renter-friendly battery CO alarm with a digital display — battery-primary for power-outage protection, plug-in for tool-free installation, and digital ppm readout for proactive CO monitoring.

Verdict: 4.2/5. The Kidde KN-COPP-3 Nighthawk is the right plug-in CO alarm when you need a proven AC-powered unit with digital display and Kidde’s Nighthawk platform — the wrong one when battery backup during power outages is a priority.