DC UPS for router?
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?
That rating from that PSU will be the max it can supply, it is very unlikely that a consumer router is pulling 5A.
Your router firmware might even expose its power consumption if you are lucky.
I have the same/similar setup. My wall-warts are just plugged into the UPS.
I was just thinking the same thing. I was also thinking you can get a wide input voltage buck converter on amazon for cheap and use a bunch of cells in series as the UPS and the buck converter spits out 12V until it cant anymore. Then just wire up a charge controller to charge and balance your lead acid cells.
The common solution is not to replace the UPS but only the battery inside. They are standard sizes and for a cheap UPS probably around 10 - 20 bucks.
Yes which is why i started building a custom 20 usbc 65w max per port box and was going to swap out all barrel pluga for matching voltage usbc receiver plugs but havent finished it yet. Not sure about battery or if i was going to add one to it
Sounds interesting, do you share the project progress somewhere?
How much loss is there for a converter? I always thought that for the most part they were pretty efficient. Unless you've measured and found a difference, you might be trying to solve an issue that isn't a huge one.
I've been very happy with my Cyberpower setup, and the smaller one is powering my router and monitors. It's still 650VA, so will roughly match the time the larger one would keep my computer alive. I'm not running a server though, so it might still be low for you, but 12V 5A doesn't seem like a large pull.
What router? 12v5a is 60w max, which is not an unreasonable amount of power. A 1500va UPS should power it for like two hours or more.
You could easily wire it up to something like that. Take the power cable, cut off the wall wart, connect the positive wire (usually red, could be white) to the positive terminal, the negative to the ground terminal. Cut off the head of a power lead, connect the live, neutral, and ground to their terminals on the AC side. Plug your battery in, the power lead into the wall, and you’re done. Check everything with your multimeter before actually wiring it up if you’re not sure. You do have one and know how to use it, right?
How about a portable power station? Basically a huge mobile battery with AC input. Some can switch over on power failure like a UPS. Some has USB PD (get 12V DC with the right cable) or car lighter socket (12V DC) or direct 12V DC output.
I’m talking about these, just a random article from my search:
https://techwriteredc.com/best-portable-power-stations/
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.
Search for “router UPS”
For example there is one from APC “# APC Back-UPS Connect 12V DC 36W - CP12036LI”
I mean, there are 12V native battery systems out there, stuff like vehicle systems.
Assuming that the 12V power supply on the router is permissive enough to take a certain amount of variation, I imagine that you can probably just put a 12V deep-cycle battery on the thing on the thing and directly hook up a 12V charge controller in parallel.
I dunno whether there’s some sort of voltmeter that you can connect NUT up to.
Personally, my position is that if NextCloud or whatever can’t handle power loss without corrupting data, that’s a bug with NextCloud. I mean, sure, it might not be able to complete an operation if there’s power loss while it’s running, but that shouldn’t result in corrupt data.
While there is DC power the battery in a UPS isn’t used. It’s not a constant AC-DC-AC conversion, that conversion only happens when there is a power outage.
The problem is that lead-acid batteries are a really shitty technology with high self discharge rates and short overall life span (their only advantage is high burst capacity that’s good for starting motors).
I would look for 12V LiFePO4 batteries in a standard lead-acid form factor that are meant as drop in replacements. Those are somewhat more expensive (like 2-3x the price) but will likely last a quarter century or more.
I am currently using an interim solution where my solar inverter has an seperate emergeny power outlet that works even when power is cut. Sadly it doesn’t switch to battery fast enough (like half a second delay 😓) for it to work as a UPS directly. But in combination with some old regular UPS that have spend batteries that only last a few minutes it works ok. But yeah, not the most efficient option conversion wise, but solar power is free 🤷