It may surprise you to hear that simply being able to last through the night, unplugged, with the display off, qualifies as exceptional battery life for a baby monitor. The Infant Optics was one of the only monitors in our testing that could easily do that, and then last a while longer the next day before needing a charge. (The manufacturer claims it lasts 10 hours with the display off—we got that amount of time off a full charge, even when checking the display intermittently.) This model also charges via a USB connection, which actually sets it apart from a variety of competitors, some of which use ineffective and inconvenient proprietary DC chargers or even disposable batteries.
Among the negative reviews, the most consistent complaint has to do with connectivity issues—either difficulty linking up initially or randomly dropping the connection while in use. These represent a slim minority among mostly positive reviews, and we did not have similar issues during our test. One consequence of losing the connection (whether it’s by a dropped link or via manually unplugging the camera) is that disconnecting causes the parent unit to emit a sharp, loud, repetitive beep. It is annoying—especially so if it happens in the middle of the night—but you should rarely hear it under normal circumstances.
Many audio/video monitors feature infrared light or "night vision" so you can see your baby on the monitor even when she's sleeping in a dark room. And some audio models feature a night light on the nursery unit that you can activate from the receiver. Other features may include adjustable brightness, and the ability to let you activate music or nature sounds to soothe your little sleeper by remote.
Wireless encryption: This ensures that no one else can tap into your monitor’s “feed” and see what’s going on in your house. WiFi-enabled monitors are great for portability and range, but may be more susceptible to hacking. If you go this route, be sure to secure your home wireless network and keep the monitor’s firmware updated. Otherwise look for digital monitors with a 2.4 GHz FHSS wireless transmission.