Hi y’all looking for advice here
I selfhost a nextcloud server and a NAS for backups, and one of my challenges has been data corruption after power failures.
I went and bought some consumer UPS units about 5 years ago, which helped, but now the batteries are starting to fail, and I’m not protected from power outages until I replace them.
I have the router on UPS as well so the computers can communicate with each other that the power has failed and it is time to gracefully shut down (using NUT).
However the router itself uses quite a bit of power and I am hoping to make a smarter decision this time around when getting a UPS.
The router’s power supply is 12V5A with a barrel style jack, so i have been searching for “DC UPS 12V 5A” to try and find something compatible that wastes less energy converting from battery DC to AC for the power supply to then convert back to DC.
But the only thing I’ve been able to find are these units designed to power electric doors: https://www.amazon.com/dp/B0D8VLPRN2/
I’m not sure if this would even be safe to use with a router, and i don’t know how i would wire it up to the router either.
I think i just don’t have enough knowledge to know how to shop for an appropriate DC UPS, or if such a thing even exists.
Anyone been in a similar situation?
Since it happens to be 12 volts to your router and many UPS batteries are 12 volts… Why not just tap the two leads coming off the UPS battery and run that to the router? After you buy a replacement battery of course, they really are cheap and easy to swap.
When charging, 12V lead acid batteries have significant higher voltages (>14V), so you basically need a DC to DC converter to make sure you get a stable 12V supply. Some (typically industrial/automotive grade) systems have that built into their internal power supply and can work directly off a 12V battery, but with consumer routers I would assume that not to be the case.
Hey, I have a lot of appreciation for the infrastructure you maintain so don’t take this the wrong way: you’re very confidently overcomplicating this one all over the thread. People run nominal 12v stuff direct from battery all the time and it’s fine. It’s the norm in RVs, boats, and off-grid housing. There’s usually quite a bit of wiggle room. The router I’m using right now won’t actually cut out until ~8v and sees almost 16 during my ancient lead acid battery’s eq cycles. It’s completely fine and has been for years. Not industrial or automotive grade by any means, a low-end Netgear from the thrift store.
You also state “while there is DC power the battery in a UPS isn’t used”. Assuming you mean AC that’s still not quite correct, it’s always being charged at least a little and tapping it for DC is perfectly fine.
That’s my advice to op, and a setup I’ve run before: replace the 12v battery attached to their existing UPS and wire the router/any other 12v devices right to it. A UPS is just a nicely packaged battery charger/inverter/transfer switch. Wiring them to larger/cheaper batteries that don’t happen to fit their casings is also entirely viable, as is running either of their outputs to a load panel. Sky’s the limit :)
Right AC. Was a typo, corrected now.
As for running nominally 12V stuff directly of a battery… you got lucky with your router then. I had the same idea with various mini PCs and ARM SBCs, and the majority absolutely should not be run directly off a battery where the voltage fluctuates so much. And it gets even worse when you try to solar charge the batteries.
I haven’t had access to grid power in over 10 years and am pretty familiar with this stuff as part of day to day life. I do now have solar. Really don’t think me and everyone else I know have been getting this consistently “lucky” for this long across such a wide range of devices. The 11-15v a nominal 12v battery system normally experiences is not a huge amount of fluctuation, and I have yet to encounter a 12v device that couldn’t take it. On the contrary, I’ve tried much dumber stuff and gotten away with it. There’s a 9v piano keyboard and a 19v computer monitor wired straight into that same battery. The only time I’ve actually killed something is by reversing polarity. Voltage too low=won’t turn on, voltage too high=gets hot, and all these years of wiring up random scavengings to see what happens have taught me most gear is surprisingly tolerant/resilient
e: for SBC stuff, automotive USB charger makes a great 5v rail. My “homelab” was at one point a pi 3b and a 5v Buffalo wifi router running dd-wrt plugged into a cigarette lighter