NOK 5G21 Gateway Battery Backup

It turns out that the battery backup not only won't keep WiFi or Ethernet connections going, it won't keep the connection either. In other words, when you get power back it will have to establish a new connection.

Mine was working fine, and after a few weeks without problems, I decided to unplug it and then plug it into a UPS. When it came back up, it wouldn't get a secondary signal (no 5G). This went on for days, and T-mobile was no help. Rebooting made no difference. Finally, almost a week later, the system  got messed up and the network was unusable. I couldn't do much other than resetting the device with a pin. After that, it established a connection with 5G, which has been working fine going on two weeks now. It wasn't a hard reset so it wasn't a settings issue.

My advice is to plug it into your own UPS and not reboot it or unplug it unless absolutely necessary. Anything I read about location or signal strength was not relevant, because if location had been a problem, it wouldn't have worked flawlessly for weeks until unplugged without being moved. And it wouldn't have stayed on 4G until some random event after a reset, and then go back to 5G even though it wasn't moved.

For those who think that maybe it's in a borderline area with respect to 5G, my download speeds with 5G are up to 600, usually a bit under 500 being typical, and upload speeds are up to 65, with around 40-50 being typical. And that's with no data errors when testing. It works great with 5G but will lose its signal even with the battery if not plugged in.

That means, in theory, that the battery serves one purpose, which is to allow you to see signal strength as you move the device around when unplugged.