--- product_id: 2072181 title: "Kidde KN-COSM-BA Battery-Operated Combination Carbon Monoxide and Smoke Alarm with Talking Alarm , WHITE" brand: "kidde" price: "$9.14" currency: USD in_stock: false reviews_count: 8 url: https://www.desertcart.us/products/2072181-kidde-kn-cosm-ba-battery-operated-combination-carbon-monoxide-smoke store_origin: US region: United States of America --- # Talking alarm announces hazard type Battery safeguard prevents missing batteries Easy install, no wiring needed Kidde KN-COSM-BA Battery-Operated Combination Carbon Monoxide and Smoke Alarm with Talking Alarm , WHITE **Brand:** kidde **Price:** $9.14 **Availability:** ❌ Out of Stock ## Summary > 🚨 Speak Up for Safety: The Alarm That Talks So You Don’t Have To! ## Quick Answers - **What is this?** Kidde KN-COSM-BA Battery-Operated Combination Carbon Monoxide and Smoke Alarm with Talking Alarm , WHITE by kidde - **How much does it cost?** $9.14 with free shipping - **Is it available?** Currently out of stock - **Where can I buy it?** [www.desertcart.us](https://www.desertcart.us/products/2072181-kidde-kn-cosm-ba-battery-operated-combination-carbon-monoxide-smoke) ## Best For - kidde enthusiasts ## Why This Product - Trusted kidde brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Clear Voice Alerts:** Hear exactly what’s wrong with loud, distinct warnings for fire, CO, and low battery—no guesswork. - • **Smart Hush Feature:** Silence nuisance alarms safely for 10 minutes with a voice-confirmed hush mode—no more smoky dinner panic. - • **UL-Certified Safety:** Meets rigorous Underwriters Laboratories standards with a 10-year limited warranty for peace of mind. - • **Dual Hazard Protection:** One sleek device covers both smoke and carbon monoxide detection, replacing two alarms with one. - • **Hassle-Free Installation:** Battery-powered and wire-free, install anywhere in minutes—perfect for renters and busy pros. ## Overview The Kidde KN-COSM-BA is a battery-operated combination smoke and carbon monoxide alarm featuring a unique talking alarm system that clearly announces the hazard type detected. It uses ionization sensing technology for fast fire detection and includes a hush button to silence false alarms. Designed for easy installation without wiring, it runs on three AA batteries and meets UL safety standards. With a compact white design, tamper-resistant features, and a 10-year limited warranty, it offers reliable, dual hazard protection for any home. ## Description Product Description When every second counts, you'll have your warnings spoken to you in a loud-volume voice: “Fire, Fire!” or “Warning! Carbon Monoxide!” Two-alarm system also announces “Low Battery” when batteries need changing. Also includes chirp signal, flashing LED and test/reset button. Uses three AA batteries (included). From the Manufacturer The leading cause of accidental poisoning deaths in North America, Carbon Monoxide is odorless, tasteless and invisible. It is a silent killer. Kidde CO alarms include the most accurate sensing technology available, the patented Nighthawk electrochemical sensor. This unit combines a Carbon Monoxide and an Ionization Smoke Alarm, providing two important safety devices in a single unit. This alarm includes a voice warning system that announces "Fire, Carbon Monoxide, Low Battery or Smart Hush Activation." The voice alarm eliminates any confusion and clearly warns you and your family of a smoke or carbon monoxide danger, or if your battery is in need of replacement. This combination alarm is battery operated, protecting you and your family even during a power outage when many incidences occur. Install at least one CO alarm on every floor and in sleeping areas. Make sure CO and Smoke alarms are at least 15 feet away from cooking or heating appliances to prevent false alarms. Replace CO alarms every 5 to 7 years to benefit from the latest technology upgrades. Replace smoke alarms every ten years. Review: Works well / Easy to understand / Great battery life - I bought this Kidde KN-COSM-B Battery-Operated Combination Carbon Monoxide and Smoke Alarm with Talking Alarm last July, since one of my old carbon monoxide alarms started 'chirping' (due to end-of-life). So far the Kidde alarm seems to work really well. Of course, as with any safety devices, you never know it actually works until something BAD happens. So it is more for "peace of mind" than anything else. The 'Talking Alarm' feature is a great help because it makes the device so much easier to use than any of my previous detectors. For example, once I inserted three AA batteries, the device goes through the test procedure, by saying "Testing" "Fire, Fire" "Warning, Carbon Monoxide" As the battery voltage gets too low, the device will actually say "Low battery". That means there's no need to dig up the product manual and struggle to read the tiny prints, in order to understand the meaning between 'long beep' or 'short beeps', and so on. If you don't have all three AA batteries installed, a safety latch prevents the device to be mounted to the base plate. This is a good safty feature, since it prevents people from simply hanging an alarm on the ceiling without batteries inside. The battery consumption is very low. I measured 0.10mA in standby. An alkaline AA battery has a rated capacity of around 3000mAh in light load. So a set of 3 AA alkaline cells should last for 30,000 hours, or over 3 years. By the way, all carbon monoxide detectors have a built-in termination date of around 7 years (something to do with the half life of the radioactive isotope in the detector). So remember to replace them promptly. [Side Note] Some people may want to use low-self-discharge rechargeable batteries such as Sanyo eneloop in smoke detectors. But that does not make economical sense in this case, since you only replace/recharge the batteries once every 2-3 years. Also in general it is not safe to use rechargeable NiMH batteries in safety devices. This is because the low battery detection circuit is designed for alkaline batteries. The voltage profile of alkaline cell starts from 1.6V and drops linearly as the battery is used up. The low-battery warning is designed to give at least one week of warning before the voltage drops too low. In the case of NiMH cell, its voltage profile stays flat at around 1.25V for most of its discharge period. But it drops rapidly as the battery is exhausted. So the warning period could be shortened to a few days of just hours. For the same reasons, using Energizer AA Lithium Batteries is also not a good idea. Review: Great CO2 / CO Alarm - This purchase was an exact replacement for the previous one in my bedroom . . . which automatically deactivated itself at the end of its 7 year lifespan (a built-in feature of this alarm). This alarm provides a voice system as well as the beeping alarm to alert the owner of either "fire" or "carbon monoxide". Both features have sounded in my home in the past, resulting from: using a cooking stove as a heat source, and on another occasion, closing the damper on the fireplace too soon after I thought the fire was out. So --- this thing works. Nice silence feature allows you to silence nuisance alarms (such as smoky cooking events) for 8 minutes simply by pressing the test button. Takes 3 AA batteries (which I prefer to the 9 volt battery that most detectors require). And, I love the mounting system: The mounting plate screws to the ceiling or wall, then the detector unit snaps into the base plate with an easy push and a turn. This allows the owner to easily take it down for battery replacement (instead of standing on a chair trying to snap in a battery). It also allows the unit to be taken down and relocated elsewhere (like outside or the garage), when there is a persistant nuisance alarm situation (like smoky cooking). This is my second one and I've found them to be trustworthy and easy to operate and maintain. 5 star device. ## Features - Talking alarm announces the hazard type detected, helping to speed up reaction time - A single unit can be installed where previously two were needed - Battery safeguard ensures the unit cannot be accidentally mounted without batteries installed - Test-reset button tests alarm circuitry and triggers the voice announcement - Meets requirements of Underwriters Laboratories (UL), an independent facility that tests products for safety compliance ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B00004WA4C | | Alarm | Audible | | Best Sellers Rank | #291,031 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #88 in Smoke & Carbon Monoxide Alarms | | Brand | Kidde | | Built-In Media | 900-0102 | | Color | WHITE | | Customer Reviews | 4.5 out of 5 stars 1,551 Reviews | | Enclosure Material | Bamboo | | Global Trade Identification Number | 00784908010209 | | Item Dimensions D x W x H | 1.8"D x 5.6"W x 5.6"H | | Item Type Name | 900-0102 | | Item Weight | 10.4 ounces | | Manufacturer | Kidde Safety | | Manufacturer Warranty Description | Ten-year limited warranty | | Mfr Part Number | 900010202 | | Model Number | KN-COSM-BA | | Number of Items | 1 | | Operating Humidity | 10 to 95% relative humidity (RH), non-condensing | | Power Source | Battery Powered | | Product Dimensions | 1.8"D x 5.6"W x 5.6"H | | Product Style | Previous Model | | Sensor Type | Ionization | | Style | Previous Model | | UPC | 251221511138 783324977752 047871072866 784908010209 047871090686 094700377241 | | Unit Count | 1.0 Count | | Upper Temperature Rating | 100 Degrees Fahrenheit | ## Product Details - **Alarm:** Audible - **Brand:** Kidde - **Color:** WHITE - **Item Weight:** 10.4 ounces - **Operating Humidity:** 10 to 95% relative humidity (RH), non-condensing - **Power Source:** Battery Powered - **Product Dimensions:** 1.8"D x 5.6"W x 5.6"H - **Sensor Type:** Ionization - **Style:** Previous Model - **Upper Temperature Rating:** 100 Degrees Fahrenheit ## Images ![Kidde KN-COSM-BA Battery-Operated Combination Carbon Monoxide and Smoke Alarm with Talking Alarm , WHITE - Image 1](https://m.media-amazon.com/images/I/51+CIUg7YJL.jpg) ## Questions & Answers **Q: ceiling** A: According to the mounting instructions, the best place to mount the Kidde KN-COSM-B is on the ceiling 4 inches 4 inches away from any wall; however, also in the installation instructions, an acceptable mounting can be done on a wall 4 inches below the ceiling but no more than 12 inches from the ceiling. **Q: I thought carbon monoxide detectors should be installed close to the ground?** A: Molecular weight of air (the mixture of gasses) is 29 g/mol, and molecular weight of CO is 28 g/mol. Air is mostly nitrogen, N2, and its molecular weight is 28 g/mol. In a still room, CO would have a slight tendency to rise. In an average house with some activity, CO would be evenly dispersed. Bottom line is that you could put the detector at any height and it should be okay, but higher would be marginally better.Contrast this with carbon dioxide, CO2, which has a molecular weight of 44 g/mol. This is significantly heavier than air. When I ferment my homebrew in a chest freezer, the generated CO2 doesn't come out quickly when I open the top. I can lower a flame into it, and it will extinguish when it hits the CO2 level. Try it, it's fun!M.Hall, Ph.D. **Q: Does this detector have a hush feature?** A: It DOES have a hush feature. Pushing the test/reset button temporarily desensitizes the smoke alarm for approximately 10 minutes. It will automatically reset and sound again if smoke is still present. This process can be repeated until the air has cleared. **Q: Is it suitable for a RV?** A: I would think so. It runs on batteries so you can put it up anywhere. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Works well / Easy to understand / Great battery life *by N***R on October 10, 2012* I bought this Kidde KN-COSM-B Battery-Operated Combination Carbon Monoxide and Smoke Alarm with Talking Alarm last July, since one of my old carbon monoxide alarms started 'chirping' (due to end-of-life). So far the Kidde alarm seems to work really well. Of course, as with any safety devices, you never know it actually works until something BAD happens. So it is more for "peace of mind" than anything else. The 'Talking Alarm' feature is a great help because it makes the device so much easier to use than any of my previous detectors. For example, once I inserted three AA batteries, the device goes through the test procedure, by saying "Testing" "Fire, Fire" "Warning, Carbon Monoxide" As the battery voltage gets too low, the device will actually say "Low battery". That means there's no need to dig up the product manual and struggle to read the tiny prints, in order to understand the meaning between 'long beep' or 'short beeps', and so on. If you don't have all three AA batteries installed, a safety latch prevents the device to be mounted to the base plate. This is a good safty feature, since it prevents people from simply hanging an alarm on the ceiling without batteries inside. The battery consumption is very low. I measured 0.10mA in standby. An alkaline AA battery has a rated capacity of around 3000mAh in light load. So a set of 3 AA alkaline cells should last for 30,000 hours, or over 3 years. By the way, all carbon monoxide detectors have a built-in termination date of around 7 years (something to do with the half life of the radioactive isotope in the detector). So remember to replace them promptly. [Side Note] Some people may want to use low-self-discharge rechargeable batteries such as Sanyo eneloop in smoke detectors. But that does not make economical sense in this case, since you only replace/recharge the batteries once every 2-3 years. Also in general it is not safe to use rechargeable NiMH batteries in safety devices. This is because the low battery detection circuit is designed for alkaline batteries. The voltage profile of alkaline cell starts from 1.6V and drops linearly as the battery is used up. The low-battery warning is designed to give at least one week of warning before the voltage drops too low. In the case of NiMH cell, its voltage profile stays flat at around 1.25V for most of its discharge period. But it drops rapidly as the battery is exhausted. So the warning period could be shortened to a few days of just hours. For the same reasons, using Energizer AA Lithium Batteries is also not a good idea. ### ⭐⭐⭐⭐⭐ Great CO2 / CO Alarm *by T***R on February 25, 2014* This purchase was an exact replacement for the previous one in my bedroom . . . which automatically deactivated itself at the end of its 7 year lifespan (a built-in feature of this alarm). This alarm provides a voice system as well as the beeping alarm to alert the owner of either "fire" or "carbon monoxide". Both features have sounded in my home in the past, resulting from: using a cooking stove as a heat source, and on another occasion, closing the damper on the fireplace too soon after I thought the fire was out. So --- this thing works. Nice silence feature allows you to silence nuisance alarms (such as smoky cooking events) for 8 minutes simply by pressing the test button. Takes 3 AA batteries (which I prefer to the 9 volt battery that most detectors require). And, I love the mounting system: The mounting plate screws to the ceiling or wall, then the detector unit snaps into the base plate with an easy push and a turn. This allows the owner to easily take it down for battery replacement (instead of standing on a chair trying to snap in a battery). It also allows the unit to be taken down and relocated elsewhere (like outside or the garage), when there is a persistant nuisance alarm situation (like smoky cooking). This is my second one and I've found them to be trustworthy and easy to operate and maintain. 5 star device. ### ⭐⭐⭐⭐⭐ So far, so good *by +***- on March 21, 2011* It was time to replace the battery on our NIGHTHAWK smoke detector and I realized that it had been manufactured in 1999! Checked the plug in NIGHTHAWK carbon monoxide detector and found that it also was manufactured in 1999. They both were working well when tested, but we've fortunately never had a fire or carbon monoxide experience, so the alarm warning was never utilized for evacuation purposes. We changed the batteries, but figured it was time to replace both units. After much research, the Kidde KN-COSM-B Battery-Operated Combination Carbon Monoxide and Smoke Alarm with Talking Alarm (also NIGHTHAWK product) was the clear winner. It was a little difficult to remove from the plastic shell packaging but was a breeze to install. The alarm will not snap into its holder without batteries in place, so on the day I was ready to install, I put in the (3 enclosed) AA batteries (must insert them in the order specified in the battery compartment) then twisted the alarm onto its holder and tested the alarm. All it's warnings functioned properly, so the old alarm was removed from the ceiling and the new base was installed onto the same ceiling location. The alarm was twisted into place and the it was tested a second time. My unit was manufactured five months ago but from what I understand, the 7 year self-destruction warning sounds 7 years from the date the batteries were installed. I personally would not purchase this in an opened package for that reason -- could be that someone inserted the batteries a year ago and returned the item. The included manual specifies that certain AA batteries be used and I don't know what occurs if one uses another brand. When I have time, I'll contact the company to check that out. I hope to only hear the warning "voice" from this alarm every time I press the test button but am comfortable with the security I feel knowing this alarm is functional. Its warranty expires in 5 years. --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.us/products/2072181-kidde-kn-cosm-ba-battery-operated-combination-carbon-monoxide-smoke](https://www.desertcart.us/products/2072181-kidde-kn-cosm-ba-battery-operated-combination-carbon-monoxide-smoke) --- *Product available on Desertcart United States of America* *Store origin: US* *Last updated: 2026-05-20*