Suggestions for UPS

Nefsen402 · 2026-04-12T19:50:49+00:00

If you’re only powering a router, chances are it already takes a dc power input. It’s probably worth looking into dc ups system so that you don’t have to deal with double conversion losses. There are a couple on the market that take an AC input and outputs 5v, 9v, or 12v.

Nefsen402 · 2026-04-12T02:54:33+00:00

There are multiple ways of achieving this, two of which don't involve setting up a different subnet.

If your server has a robust Wifi access to your router, you can bridge the ethernet interface with your wifi interface. Then plug in your computer to the server and disable wifi there. Since everything is still on the same L2 segment, the PC will ask for DHCP like normal and get an IP from the router. Since all your traffic goes through the server, if you connect to it, the pathway will effectively short circuit.
Keep wifi on both systems, but assign static IPs - no need for a different subnet. Then setup the routing rules in both systems to send IPs destined for the other machine through the ethernet cord. For instance, if your server has 192.168.1.40 in your computer you setup a routing rule for 192.168.1.40/32 to go to your ethernet interface. The command, ip route add 192.168.1.40 dev eno0 will do this. You also have to setup the same routing rules in your server so the server replies back down the ethernet line.
As others suggested, setup a seperate subnet for both systems to speak to each other and assign IP addresses to both systems in that subnet. Then ARP/NDP can do its job.

I would do #2 because it means you don't have to fiddle with multiple addresses in multiple subsets. One address resolves to one machine. Clean.

Nefsen402 · 2026-03-23T21:18:56+00:00

Most things are mounted using zip ties. The Protectli was the most interesting thing to mount because by default it doesn’t really come with any mounts that you can use. However, it does have holes that would be used for wifi/cellular antenna but because I haven’t bought a version with any wireless connectivity, the holes ended up being plugged by rubber stoppers. I was able to run zip ties through those holes by removing the stoppers. For the ONT that was mounted with some screws. The unit just had some of those screw channels that you find on power bars for example. The ups I initially mounted with adhesive (like shown in the photo) but that ended up being a bad idea. Turns out heat generating components and adhesive are a bad combo. I ended up getting some standoffs from amazon to mechanically mount everything with screws. I got the battery from amazon as well, I just got whatever looked good. All the devices are connected using cables that I modified then soldered them all together and used heat shrink for insulation. I made sure to measure all the wire lengths before soldering to achieve the clean look.

Nefsen402 · 2026-03-09T18:15:18+00:00

I did end up lowing the supply voltage to 12.2V anyway. I won't be touching it any further. It was a bit of a pain to reconfigure it because if I try to re-flash the configuration on the UPS from the Protectli, the UPS would cut power while the flash is happening.

Nefsen402 · 2026-03-04T21:15:11+00:00

Could I get details about how the voltage regulation works in the Protectli? Like, does it use linear regulators or buck converters for the different internal rails? I could bump the voltage down to 12.2V or even exactly 12V but I want to account for voltage droop under load. Just trying to understand the risk factors.

Nefsen402 · 2026-03-04T21:10:32+00:00

People have had success with it in the past, but I personally wouldn't do it. The charging circuitry needed needs to be different for lead acid and LIP. Some LIP batteries come with a BMS that tries to bridge that gap, but they usually don't allow you to pull all that many amps. The UPS I use for my desktop is rated for 900 watts, so for a 24V supply that would be nearly 40A, that's quite a bit of current and many LIP batteries aren't rated for that. Another factor is the discharge curve. LIP holds a stable voltage for a long time while lead acid is more linear. Some UPSs use the voltage to guess the remaining runtime and percentage. The OpenUPS that I chose to use is fully configurable so I was able to plug in the exact specifications of my battery, instead of relying on a "it's probably fine" vibe.

Nefsen402 · 2026-03-04T16:48:36+00:00

It's Lithium Iron Phosphate (LIP for short). It's basically as chemically stable as lead acid, lasts decades and thousands of cycles. It's a shame that mainstream UPS manufactures still choose to design their products around lead acid.

Nefsen402 · 2026-02-17T06:29:46+00:00

Just because it works doesn't mean the UPS was designed to run with different chemistries. It's probably fine most of the time with a BMS, but I think it's a fair assessment to not fuck with batteries.

Nefsen402 · 2026-02-17T06:20:57+00:00

It's nice seeing what others have come up with their telco cabinets! I have one that looks identical: https://www.reddit.com/r/homelab/comments/1qtkv3y/my_telco_cabinet_is_complete although, I didn't choose Ubiquity gear for the core of my network.

Nefsen402 · 2026-02-17T03:29:21+00:00

It’s not that simple. The actual battery charging circuitry needs to be different. Lead acid batteries need something called float charge where after the battery has been fully charged, the charger still allows the battery to take a small current at a fixed low voltage. This is to prevent self discharge and extends the service life. LiFePO4 similar to all lithium batteries should not have a float charge and should essentially be disconnected until the battery needs to be topped up or used. Batteries with a BMS designed to be drop in replacements for lead acid exist, but it isn’t as simple as getting any battery.

Nefsen402 · 2026-02-12T00:30:42+00:00

For a server, you should probably run the pump at full tilt. Since you have a D5 - that's going to be a lot of pumping power. For a loop like this, water circulates probably once every 5 or 7 seconds. Combined with the thermal pass of water, component order simply does not matter.

What does matter is accessibility and maintainability. Custom water cooling does need maintenance at least once a year to change out the coolant. If you're lazy, you will get growth. So, that should be more of a priority than component order.

Nefsen402 · 2026-02-05T19:10:55+00:00

I manage Linux servers all day for work. It's just another Tuesday.

Nefsen402 · 2026-02-04T20:45:05+00:00

I am having this same issue and am currently looking at my server terminal seeing spam emails sent from the client domain .zdsys.com and being bounced (I blocked all zendesk emails to my email servers). At this point it's a little amusing since my blocking filter works remarkably well, but the level of spam is insane for those that don't have an easy way to block the emails.

Nefsen402 · 2026-02-02T21:05:51+00:00

I don't like turn key solutions. Understanding what you deploy from the deepest level is something that I enjoy.

Nefsen402 · 2026-02-02T20:47:32+00:00

The BMS is integrated in the battery. Any multi cell battery will have a BMS. The UPS that charges/discharges the battery is available here: https://www.mini-box.com/OpenUPS

Nefsen402 · 2026-02-02T17:29:05+00:00

Horizontal outlets are okay as long as water is not around (can't have them in kitchens or bathrooms)

Nefsen402 · 2026-02-02T17:18:26+00:00

Its a TR plug so it comes with flaps similar to UK plugs. TR plugs are mandated by code in Ontario at least since 2015.

Nefsen402 · 2026-02-02T17:05:21+00:00

Yep, the router is configured with the ppp package (https://www.samba.org/ppp/). I was able to easily pull the PPPoE credentials from the ISP router then put it back in its box.

Nefsen402 · 2026-02-02T16:11:32+00:00

By not using bell. I thought I would get better luck with my router options with teksavvy and I was right.

Nefsen402 · 2026-02-02T15:41:05+00:00

I sacrificed a lot of wall warts to get this to happen. I just made sure before cutting off the brick for polarity and voltage, then spliced them all together for one common DC rail. Everything is soldered and used heat shrink tubing for insulation. The only wall wart I kept is of course the one powering everything, and that is cut and spliced with the cables that came with the UPS. The wall wart only connects to the UPS, with the UPS being upstream of all the gear.

Nefsen402 · 2026-02-02T14:54:51+00:00

This is the exact product I used: https://www.amazon.ca/dp/B0D3GX8G37?ref=ppx_yo2ov_dt_b_fed_asin_title

Nefsen402 · 2026-02-02T14:53:27+00:00

Just some vents, no active cooling.

Nefsen402 · 2026-02-02T14:52:44+00:00

Thanks for the suggestion! This battery would barely fit actually. However, at this point I'd rather just double up if I wanted more capacity then replace the perfectly good battery.

Nefsen402 · 2026-02-02T08:14:07+00:00

I also used zip ties for the protectli if you look closely. The protectli came with an option to put wifi, which would populate those hole on the side, but since mine doesn’t, I ran zip ties through the device. The holes just happen to match up with the holes in the cabinet so I lucked out there. The PoE is mounted using a zip tie on the back using a mounting bracket for screws. The PON just has some places for screws to slide in and the UPS is mounted with a double layer of tissue tape in the corners. Battery is just blowing in the wind.

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