I'm currently traveling for months at a time and my homelab has become unreachable to me over VPN due to a unknown complication after a power outage.
Just as a learning experience for all, my mistake was that I set-up my VPN very far down the stack - as a wg-easy app inside TrueNAS SCALE's apps ecosystem. My very important reason for doing it was that way was that wg-easy allows for setting up client devices with a QR code...
Anyway, the NAS is not booting back up nor do the TrueNAS apps. I should've set my VPN up right at the front of the network - on my MikroTik router that also supports Wireguard. The funny thing is I was so happy that my NAS has IPMI and whatnot but now I can't even access it.
For now the NAS is kept powered on from what I know, it just doesn't boot. This should help prevent bitrot until I'm back. All important files are backed up on a 3rd party service.
It's a shame my Jellyfin and Navidrome inaccessible, but I'll live.
Now I'm thinking about buying an UPS so that this doesn't happen in the future. I'd like the UPS to be fanless and rackmount, so that limits me to ~700VA territory.
Devices in my homelab pull about 65W idle and spike to say 150W when everything is booting. ISP modem, router, POE+ switch, AP, NAS. I might add another 20W due to a Lenovo M920q in the future.
I only really care about NUT and graceful shutdown instead of long runtime on battery.
I was thinking about this: https://www.apc.com/us/en/product/SMT750RMI2U/
In my country I can get it with new batteries (no front panel) and a network card for NUT for a total of 180 EUR.
Would that work? Would you be afraid of leaving an UPS (it is kinda like a bomb after all) unattended an leaving your home for 6 months at a time?
Do they make them with LiPos? Everything I've ever owned had sealed Lead/Acid batteries. Really hard to cause any damage with those.
Lead acid can boil over and fill a badly ventilated room with flammable hydrogen and other toxic gasses.
A well maintained LiFePO4 battery that some modern UPS use it probably less risky, but I think the risk for both is very low.
To highlight the low risk, every (non-EV) car in the world uses a lead acid battery.
Had one of power powervar's lead acid batteries swell up and overheat on us, but it was probably also installed several years ago.
As long as you replace them on a regular basis, totally fine.
There are probably newer ones that come with LiPos. But every consumer grade one I've seen is traditional lead acid batteries.