Roost packs smarts into a familiar 9V form (pictures)

It might look like an ordinary battery, but Roost is anything but. Complete with Wi-Fi capability, Roost will send you a notification should your smoke alarm sound. Click through to see how this smart device can add retrofit connectivity to your old smoke detector.

Roost looks just like a 9V battery.

And it installs into your old smoke detector.

Put Roost into your smoke detector and install the app on your phone.

The app will walk you through the rest of the steps to connect the battery to your router.

And you're done. Roost's setup was as easy as any smart device I've ever tested.

Roost's main app page and menus show all is well.

You can easily add additional monitors to Roost, so your family can also receive notifications when an alarm sounds.

The bottom of Roost pulls free, letting you peek at the packed-in tech.

On the back of the battery, you can see a small microphone. Pull off the bottom to see Roost's circuits.

You can also replace Roost's power source when it runs out, though Roost claims its battery can last up to five years.

Once you're up and running, Roost stands guard for smoke.

When an alarm sounds, your phone's notification will sound like a siren. Pull up the app, and you'll be prompted to take action. Roost's emergency contact defaults to 911.

By swapping out the battery, you can make your old smoke detector smart. Thanks to the Roost Smart Battery, you'll be notified of any alert no matter where you are.