In a nutshell: Comcast has become the first Internet service provider to introduce what it describes as a product designed to keep you connected when the weather gets rough and the power goes out. The new Storm-Ready WiFi device is a two-part backup connectivity solution consisting of the router itself and a battery backup unit. When there's a loss of power, the Storm-Ready device will automatically switch your Internet connection from broadband to its integrated 4G LTE cellular connectivity.
It is not fast, topping out at up to 30 Mbps download / 7 Mbps upload, but it is better than nothing. Comcast said actual speeds will vary and are not guaranteed, so take that for what it's worth. The battery backup can keep you online for up to four hours through network and power outages, and there is no additional charge for using the unit's cellular connection.
Of course, a connection to the outside world is of little use if your devices aren't charged as well. As such, we would recommend keeping an external battery pack or two fully charged and at the ready at all times.
When not serving as a last resort, the Storm-Ready WiFi device serves as a tri-band WiFi 6 extender to help eliminate weak coverage zones in your home. It also features two Ethernet ports, measures 110 mm x 110 mm x 160 mm (4.33 in x 4.33 in x 6.29 in), and weighs two pounds. The separate battery backup is a bit smaller at 98.5 mm x 41.25 mm x 110.25 mm (3.87 in x 1.62 in x 4.34 in) and tips the scales at 1.04 pounds.
Comcast said you will need an Xfinity Gateway and a speed package of at least 800 Mbps or faster to be eligible for its Storm-Ready WiFi device. Pricing is set at $7 per month for 36 months, which works out to $252 over the course of three years. It is available to purchase from today at Xfinity Stores and online.
https://www.techspot.com/news/99795-comcast-introduces-storm-ready-wifi-solution-battery-backup.html
