Hardwire Smoke Alarm with 10-Year Battery Backup | SMI105-AC

This smoke detector works as advertised. Installation was easy and straightforward. Don't know if it will last the 10 years, but as of rIght now it seems sturdy and well built. I recommend this product.

Very easy to install. I bought two 3 packs, I needed 5. Installed the 6th in a neighbor's condo that only needed one. I got rid of all my old 9v battery backup detectors. 10 year battery is Great! The Fire Inspector came, tested it, and gave it a Thumbs Up. I'm good for 10 years.

Quickly replaced my aged-out 10-year-old detectors, fit exactly in the already in place holder. Used the exact same plug system, and so it required no rewiring, and they not only tested perfectly, the interconnect compatibility alarmed all of the exiting working units in my home- as they should! They are loud! They are also a great value with the 10-year battery, so that means I can set it and forget it! Will absolutely purchase again when needed.

Screws to mount were missing but otherwise I'm very happy with it. Easy install once I found my own screws. Really like the 10 year battery as I am getting to old to climb up on a ladder to change a battery

I ordered 2 of these 3-pack of First Alert Smoke Alarms in June of 2026 and I was delighted to see that they were manufactured in May of 2026; i.e., they hadn't been sitting at the warehouse for 5 years. The batteries were fresh and ready to go. I removed all the old ones and installed all of these in my house. They all worked when tested. ...Let's hope I never need them.

Replaced my old units with these. Good instructions made them easy to install. I like that it has a built in battery that is good for 10 years. Fairly priced too.

I have had this smoke detector for 14 months. I arrived home around midnight from visiting a family member in the hospital and it was doing a low battery chirp. This product description indicated a 10 year battery life, this is false. Now I am struggling to try and change the battery at midnight. There is a lock on the battery compartment to prevent opening it. It took an absurd amount of time to figure out how to remove the pin, you access it UNDERNEATH the unhelpful sticker directions on the back. I replaced the battery only for the chirping to continue. Upon reading the product manual I have found that you cannot replace the battery and instead need to dispose of the entire device and buy a new one. This manual also indicates that they offer no warranty or guarantee on battery life. I am not capable of disconnecting this hardwired device. I also cannot afford to buy a new smoke detector every 14 months. I am stuck listening to a low battery chirp until I can get someone out to disconnect this smoke detector. Extremely disappointed.

Easy install, fits existing First Alert Smoke detector base. Recent (just a couple of months) date of manufacture and resolved the constant false alarms from the 2 year old ones installed in my house.