It's shame that Sonic doesn't offer UPS's for Fiber installs or at least recommendations. I suppose it's understandable since their recommendations could be used against them by some folks which is sad. Anyway, here is what I've found:
First, it looks like a company called HSN Tools has a UPS specifically for this router:
Note, I have no experience with this at all but I'd likely go this route if I didn't already have a DC UPS.
As those of you who've seen my posts before I have this UPS that I had hooked up to the BGW210:
https://www.neobits.com/apc_schneider_e ... IIQAvD_BwE
This worked great for 1.5 years and the BGW210 even provided enough power via its USB port to power the ATA which was great as I then had internet and phone for a number of hours during a power outage.
Now that I have GIG (which is great BTW) I wanted to make use of my existing UPS. Here is what I did:
1) Ordered this: https://www.amazon.com/dp/B09MBDQ69J?ps ... ct_details
2) Ordered this: https://www.amazon.com/dp/B07JMY5XXT?ps ... ct_details
3) Picked up some shrink tubing from Home Depot.
4) Pulled apart the BGW320 power supply. This was pretty tough but a knife and screw driver got the top off see BGW320-Power pic attached.
5) Cut the white and black wires back and then cut off the end that fits in the case. See 2-wires pic attached.
6) Strip white wire (this is 12V +) and then solder the ends of both the white wire and the shielding/ground to make getting them into the barrel connector (female) easier. Note I had to crimp down the ground since it's thicker but once it was soldered it went in fine.
7) Put shrink tubing on the bare shielding/ground wire exposing about 1/4". Put larger shrink tubing over the entire thing leaving just the ends exposed.
8) Push the white wire into the + side see barrel-end pic attached.
9 Do some voltage checks to make sure you've got it all right, plug in and be happy that you now have some hours of internet during a power outage.
Oh, and I think there have been a lot of questions on how much power this BGW320 uses. I plugged it into a KiloWatt and with everything powered up and nothing really using it it's right at 13.5 watts. Streaming a YouTubeTV sporting event, a Pluto TV show and doing a speed test (getting 700+MBs both up and down) while attached to that AP it went as high as 19.2 watts. That's about the highest I saw it get which is good since that APC UPS maxes out at 38.4 watts.
Hope this is helpful for some folks.