Initial handwaving suggests power needs aren't too unreasonable.
Swann run their 4 camera CCTV systems off two 12 volt 2 amp wall warts. One for the cameras and one for the recorder / control box. My BT Home Hub also has a 12 volt 2 amp wall wart which I assume is pretty typical. So thats a theoretical 6 amp demand from the simple 12 volt CCTV and router idea. I imagine there is some margin between the wall wart output and what the kit actually uses when running flat out. I also suspect that in passive daytime watching mode the CCTV draws rather less than when recording at night with the IR illuminators on.
Approaching a couple of hours from the 9 amp hour float batteries often found on alarm systems is probably not unreasonable.
My boiler specification says 60 watts power draw, the heating pump needs 50 watts maximum and the other control gubbins soak up around another 30 watts or so. Given the various inefficiencies in battery to inverter conversion calling the boiler et al demand 180 watts is probably in the ball park. So nominal 30 amps draw from the 12 V battery for the heating when its running.
But in "frost protection plus a bit more" mode the heating won't be running all that much. If its 10 % duty cycle then a 30 amp hour battery ought do for about 10 hours.
A 100 Amp Hour leisure battery can be got for around £100 and would likely be enough to run both the heating in "frost protect plus a bit more" mode and the 12 V CCTV et al stuff for a 10 hour (ish) power cut. Which ought to be enough.
Another £200 should cover a small pure sine wave inverter (500 W) and decent quality battery maintenance charger so it all looks somewhat doable without spending silly money.
But its certainly something I'd prefer set up by "folk who know" rather than me working 'undreds of miles from base.
Clive
Edited By Clive Foster on 07/10/2022 18:59:34
Edited By Clive Foster on 07/10/2022 19:05:28