Is TalentCell Y1206000-USB a good DC UPS solution for routers?

I have a Netgear switch in the basement and a Synology MR2200AC upstairs – and I want to make sure connectivity stays up during the (so far very rare) power outages.

My modem and main router are plugged into APC UPS Battery Backup (BE600M1) but it’s very bulky and I want to use a DC UPS for the switch and the wifi access point instead.

I purchased a TalentCell Y1206000-USB battery which I believed would be suitable for the task. However, the instruction manual says not to keep it plugged in and charging all the time, which defeats the purpose of having a UPS.

Below is the photo of my current setup where I used the splitter that came with the battery to plug it both into the wall and into the Synology box.

Is this a problem? If yes, what should I be using instead? The basement setup would be similar (a single lightweight networking device plugged into the battery).

MR2200ac router plugged into a TalentCell battery