I keep having multi-hour power outages a few times a year, so I decided to build a battery system a few months ago. I was happy with it during a recent four hour high-wind winter outage, powering my 120V furnace, fridge, desktop PC, some lights and chargers. Here's what I ended up with:

- Bluetti Elite 200 V2 portable power station: $999, 2073 Wh LiFePO4, 2600 W inverter output (120 V only), 1000 W DC input at 60 V max, Bluetooth & Wi-Fi connectivity to app, 53 lbs [1]

- LiTime 51.2V 100 Ah battery: $999 (includes charger), 5120 Wh LiFePO4, local Bluetooth connectivity to app, 82 lbs [2]

TOTAL: $1,998 for 7.2 kWh = $278 / kWh (before 30% tax credit). Plus tax and a few hundred more for the random bits and bobs.

Here's a video that talks about using the big bulk LiFePO4 battery to extend the power station: [3] This setup can supply 2600 W for about an hour (limited by the Bluetti's inverter and internal battery capacity), or 1000 W average for 7 hours (limited by the Bluetti's DC input). Limited to 120 V loads only, of course.

For me, this made the recent outage smooth sailing, running a few hundred watts average load for furnace / fridge / small conveniences. A friend nearby had pipes freeze and burst ($$$ repair and highly inconvenient) during a 20-hour winter power outage. It was nice to have a longer buffer to get a good night's sleep and know that everything would be fine even if utility power didn't come back quickly!

I think the original poster here is latching on to a basic issue that the consumer-grade UPS companies (APC, CyberPower) are being slow to adopt LiFePO4 batteries. At the same time, the "portable power station" companies (Bluetti, Anker Solix, Ecoflow, etc) have been recklessly marketing that they have UPS functionality, without delivering on that until recently. Be careful if you buy one: many of these portable power stations will not turn back on their AC output unattended if they fully discharge before the utility power comes back on! Just recently, they are starting to roll this out on some models: Bluetti calls this option "System Switch Recovery", and Ecoflow calls it "AC Always On" -- and neither are enabled by default!

And I 100% recognize that I'm in the tiny minority willing to combine these products together to get a lower overall $ / kWh. But maybe you are too :)

[1] https://www.amazon.com/dp/B0DCJV9LTB [2]