You hear that chirp, chirp, chirp. Spiders and dust can get in there. Also, did you know you need to replace your smoke alarms every 10 years?

The Fremont Fire Department wants to help members of the community who are unable to replace the batteries in their smoke alarms.

Prompting the campaign is research showing only 76% of householders replace their smoke alarm batteries regularly. Nearly 5% of smoke alarms don't work because the battery is dead or has been removed.

Enter companies like Roost — which just released its first device: a smart battery designed to make battery-powered devices like a smoke alarm "smart" without having to replace them.