[Brad] was asked by his Sister to design a motion-based alarm that would help her catch ... that is only active at night and can be battery-powered. What he came up with is a light-sensitive ...

Basic alarm clock & battery operated clock - This clock is powered by 4 x AA alkaline batteries only (not included), which can keep Constantly Big 1.2'' LED digit time display for more than 12 months.

We spoke to a fire safety expert and weighed the pros and cons of cost, reliability and installation of hardwired smoke alarms versus battery-operated. Here’s everything you need to know.

It’s battery-operated and can be interconnected, so if one alarm goes off, the others will follow. Kidde also offers a highly-rated battery-powered detector, and Walmart’s Siterwell model ...