Power Bank as a UPS and off-peak "arbitrage"

[clockworks]

We have a 23KWh house battery, which isn't quite big enough at this time of year (heat pump).
Gets charged up overnight at 6.6p per KWh.
No gateway, just an EPS socket for power when the grid goes down (3 power cuts so far this year).

Also got a small traditional UPS to keep the router online, but it starts beeping after an hour or so of no grid, and then needs plugging into the EPS socket via an extension lead.

I was looking into a UPS solution that can keep the router, WiFi Mesh master unit, Mini PC running Home Assistant, and the Synology NAS (all located in the understairs cupboard) going during a power cut. Bonus if it can take some of the load off the house battery (recharge from the grid overnight, run the kit off the battery during the day).

We've already got a Bluetti Elite100 (1KWh), so I've been testing the idea with that. It's not really big enough to last 24 hours, but it does work. UPS changeover seems fast enough.

Looking at 2KWh units, the Anker Solix S2000 seems ideal, around £850. Sub 10ms UPS, work mode scheduler, Home Assustant integration, etc. Anything else out there that's cheaper?
The Anker is built for efficiency, rather than peak output, which seems to suit this application.

Edited to add:
A proper gateway for the house battery would be nice, but due to the house wiring and layout, that'll cost £3k

[cliffords]

Good heavens what on earth are you talking about.

[Mammasaid]

Ignore the dinosaur.

Coincidentally, Andrew Til was discussing something very similar today, might be worth a watch.

[bunchofkeys]

There were a couple of threads recently that looked into what you're asking. I cannot remember which one exactly, but take a look at the Stockpile, Solar or Portable battery conversations.

[Funk]

cliffords said:

Good heavens what on earth are you talking about.

I understand it.

Genuine question; you clearly don't, so why did you take the time to reply, particularly in that tone?

You need to accept that sometimes people will talk about things you don't understand; that's not their fault and doesn't mean they shouldn't post.