
UPS I just simply leave it connected to an electric socket outlet so remains continuously charged , mine has been sitting in circuit since 2017 ,all that is connected to it is the Davis console and router as I use a NANOSD .The advantages are the NANOSD continues to log data without the need of having the batteries inserted ,which would probably not last long as the consumption drawn by the NANOSD would likely flatten(batteries) them in a few hours . I also have a router which simply has a USB port which allows me to connect my 3g travel dongle which uses my cellphone/smartphone carrier service. generally power cuts are not as frequent these days here but back in 2017-2018 it was weekly sometimes daily especially during hot periods as most households have air condition units (you can't live here without one in June,July,August and early September you would never sleep ) but last couple of years its improved vastly to once a month but we are now notified in advance of downtime ..
I paid around $50 (based on exchange rate at the time) in 2017 ,this is the model below , but they probably come in different brands but 1500va is good for 48 hours for a console and router , if you were to run other items off it it wouldn't be that long ..
have a good day..