I admire Roost's approach to smartening up the home one 9-volt battery at a time. The company's latest gadget looks a lot like the original Roost Smart Battery ($37.02 at Amazon.com) that fit into your smoke detector, except this one slides into a plastic case that mounts on the top of your garage door. Once in place and connected to Wi-Fi, the Roost Smart Garage Door Sensor can send you notifications if you forget to close your garage.

The main piece of the Roost Smart Garage Door isn't exactly a 9-volt, it just looks like one. It's missing the usual terminals and it has an accelerometer built in, so it knows when the garage door moves.

The original Roost battery built Wi-Fi and a microphone into a 9-volt so it could know when your smoke detector sounded and send you an alert. The Garage Door Sensor can also send you alerts whenever the garage opens or closes. If you don't need that much info, you can customize what notifications you want based on time of day or time passed since it opened or closed.

For instance, you can get an alert that it's still open 5 minutes after you first opened it to leave, so you know if you accidentally drove away and forgot to close it. You can also get an alert if it's still open at night or if it opens between 3 and 4 p.m. when your kids are due home. You can also always check the app for an updated status on the door.

Note that if you do discover your door is open after you left, there's nothing Roost can do to fix the issue. The sensor can't actually control your garage door like the Chamberlain MyQ Garage ($114.15 at Amazon.com) Door Opener, but whereas the Chamberlain smart garage is $130, Roost's sensor is only $40. The Sensor will only be available in stores in the US at first, but Roost is partnering with insurance companies that may bring it to other countries. The US price converts to roughly £30 or AU$50.

You'll be able to buy the Roost Smart Garage Door Sensor this spring. The battery is rated for two years of life and replacement batteries cost $10. Just like with the $100 Nest Protect ($168.00 at Amazon.com) and the original $35 Roost, the Garage Door Sensor looks to be a nice affordable alternative if you don't want wholesale smarts but would like a little extra peace of mind. 

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