If it’s a relatively recent laptop, it should be fine.

Many of them will let you set custom charge limits. If yours supports that, limit it to like 60% or thereabouts. Long enough that you can get some UPS use out of it but not full enough it’s ever gonna go spicy pillow on you.

If it won’t let you set a charge limit, they’ll still kind of float around full charge but not stay at 100% all the time. Even plugged in, mine will drop down from 100% to eventually 92% before it will start charging back to 100 again. That’s over the course of several days to a week.

If the laptop is older than about 2017 or so, or still has a removable battery, you might want to just take the battery out and use an external UPS as those typically don’t have the extra charge management features newer ones do.

To run them full time, you either want to remove the screen or “tent” them because a lot of heat is dissipated through the keyboard, and it’s normally expected to be open while running because of that. By “tent”, I mean open it halfway and put the screen facing down so it’s standing up and shaped like a tent.

A few years ago I decided to try the lithium-ion UPSs. I’m on my 3rd year with them, and I will never go back to lead acid. I’ve got one “classic” UPS that is still in good shape as long as you don’t try to run more than 100w from it, but when it goes, it goes.

These use the LiFePO4 batteries, and I get close to twice the runtime as my old ones, and they don’t drop from 80% to 10% like lead acids do. The battery chemistry is also good for about 10 years of daily cycling, so assuming the electronics hold out, they seem like they’ll last.

The only hiccup with the model I got is it doesn’t have a serial monitor connection, but you can probably fine plenty that have it.

Ugh, yeah. My “temporary” spinners that were an emergency upgrade became permanent when I went to buy the new ones and prices had skyrocketed. I’ve got one cold spare left, so hopefully there’s a price break in the near-ish future

I feel that.

Before I downsized, I was running 3x HP DL360 G6’s with dual Xenons and 96 GB RAM each. Way overkill for my needs but I got them cheap. Unfortunately, they and my air conditioner competed to see who could use the most electricity each month. 😆

The only thing I really lost in the scale down was the ability to spin up dev/test VMs for every little purpose. I’ve mostly just started using Docker containers for things like build environments.

Their Intel graphics work great for transcoding, but yeah, not much else. I’ve got Emby one one of them, and the QuickSync hardware acceleration works well even with multiple simultaneous streams.

Works pretty great as long as you keep your expectations realistic. Easy to upgrade and pretty reliable. Only annoying thing with any of those micro PCs is the cable management is a pain because of the power bricks. I got some USB-C PD adapters and Dell-style cables and that’s made a huge improvement.

About 220W on average with peaks around 280W. I’ve got 8 Optiplex micro PCs, 5 upcycled thin clients running smaller services, fiber ONT, another micro Optiplex as a router, a storage server, main switch, and a 5 port PoE switch for my 4 access points around the house.

Before I downsized everything to the USFF PCs, I was running 3 old enterprise rack servers that were about 220W each.

It’s currently running from solar from about 7am to 4pm with my small solar setup, but I’m in the process of installing a whole house PV system so hopefully will be 24/7 solar powered soon-ish.

I’ve been told that government auctions canbe a good source for cheap used PCs

Can confirm government surplus auctions or sales are a great source for cheap PCs and that they do get snatched up quickly (guilty!) The only other catch is they never come with hard or solid state drives. I’m assuming those just get pulled and destroyed.

Thanks, and yeah, it’s been fun putting that all together. Unfortunately I’m still learning FreeCAD so they’re not as integrated as I’d like yet, but as soon as I have time to hammer out a design, I hope to have all 3 of these and the UPS/power supply in a nice case.

Yep, running/charging it from solar is why I ended up getting that chonky 18650-based UPS board. It’s the only one I could find that could combine 5V input and battery without dropping out (battery kicks in immediately if solar insufficient and draws the difference between input and output and charges and powers simultaneously otherwise).

Thanks!

What are the use cases for taking it with you instead of just connecting to your homelab?

I built it just to see how much I could cram onto a Pi Zero clone/how many self-hosted services I could have on something I can fit on my keychain, and the answer was “a lot”. It’s something of a travel server, travel router, emergency backup server, etc.

I mainly just wanted a subset of my homelab services available in something I could take with me anywhere. Home lab could go down while away, power could go out, something to use while glamping, can take it with me if there’s ever an emergency where I have to evacuate, etc.

What started out as a single unit has become a three unit portable stack lol. Yay feature creep!

Services

• Jellyfin (all content pre-transcoded so everything can direct stream)
• CodeServer (setup for Python, NodeJS/Bun + React, and Platform.IO for ESP8266/ESP32 development)
• Kiwix (including the full Wikipedia dump with images as well as offline docs for lots of code libraries I work with, etc)
• SearxNG so I always have a sane search engine available
• CalibreWeb with my whole ebook library
• MPD+Snapcast+My whole music library. Also has myMPD web UI for controlling MPD. Snapcast clients can connect, and it can serve multi-speaker/multi-room audio
• PiHole serving both ad blocking and local DNS as well as providing DHCP for the access point
• PairDrop for sending/receiving files
• NodeRED and Mosquitto MQTT for setting up ad-hoc automations
• Nginx with real LetsEncrypt certs so all services have valid SSL certs and hostnames

Networking

• One USB port is configured in ethernet gadget mode. Can plug it into a host PC and get an IP address from it
• One wifi adapter is setup as an AP and is bridged with the USB ethernet (a PC plugged in and a wifi client are on the same L2 plane).
• The second wifi is the “WAN” connection if one is available. Can alternatively connect to USB tethering on my phone
• If there is any kind of “WAN” upstream, the LAN bridge (USB ethernet/Wifi) will route to it
• Wireguard to connect back to my homelab.

File Services

• Samba
• Encrypted LUKS volume for critical docs (tax records, vet records for the dogs, etc)

I’ve got a second unit that connects as a client to the main one with some additional backup services:

• Email stack( Dovecot, Postfix, SpamAssassin, ClamAV, Webmail)
• Matrix/Synapse stack
• Asterisk
• Snapcast client

The second one is basically a backup to my main stack in case of disaster/power outage/etc. Those all tunnel to a cloud VPS + load balancer and only need an internet connection to setup the tunnels to receive traffic from the VPS (and route back out to it). Those services are stopped and a cron task keeps them in sync with the main ones in my homelab. If I need to fail over, I just SSH into the VPS and re-route traffic to them instead of my homelab endpoints.

I self-host my own email and chat and phone services, so those have become critical services I want to always have online. Essentially these little Pi clones are a backup stack for my most used services and one that is both extremely low power and portable should I ever need to host them on the go (house burns down, have to evacuate due to emergency, etc).

Third Unit (Still on the bench)

I have a third unit that’s built on a PiZero2W but it’s still on the workbench (but functional!). Just haven’t gotten any kind of case at all built for it.

It’s got two RTL-SDR units attached. One is tuned to the NOAA weather radio station and feeds into Snapserver on the main unit (so you can listen to the weather radio anywhere on the network) as well as piped into Meshtastic EAS-SANE alerter in order to forward emergency alerts to Meshtastic. There’s a USB-connected Meshtastic node attached as well for that.

The second RTL-SDR is setup as a generic FM radio tuned to the local variety station. It’s just piped to Snapserver on the main unit to make it available on the network.

I may convert the second SDR into a ADS-B listener, but for now, I like having the FM radio available.

I run Jellyfin on a Banana Pi M4 Zero. It’s a little less capable than the Pi4 but runs JF just fine. Specs on this one are quad core 1.5 GHz, 4 GB RAM, 32 GB eMMC on Armbian.

The media files are all on the 1 TB SD card while the Jellyfin data directory (especially the SQLite DB) are on the eMMC. This seems to work much better as the DB file kept getting corrupted on SD. Should also help the SD card from wearing out since it’s pretty much only reading data from it most of the time.

As you guessed, transcoding is not going to work (JF is removing the v4l2 hardware support anyway), so I pre-transcode them to H264 + yuv420p in an mp4 container before moving them to the SD card. I also scale them down to 720p to fit more on there, but that’s because this is a travel server and isn’t my main media source.

Can’t speak for Paperless though.

Mine’s only for people I know personally, so it’s backed by my LDAP server and registration is disabled in Synapse. I use my regular onboarding process to create the new LDAP user and grant access to Synapse.

Nice! Those AllWinner boards are a little tricky to get going and have some quirks, but the price is great for the extra horsepower you get. Granted, I use the latest Armbian since the manufacturer’s images are all quite old.

130GB for the entire thing? And the pi doesn’t choke on indexing / searching it?

That was my thought. I knew it couldn’t hold it in RAM but thought it would be doing crazy IO and limited by being on SD, but it seems to not be a problem. Like I said, I don’t know how ZIM does it, but it does it well. Must have some kind of index that lets it fast travel to the correct blocks or something. I dunno lol.

how capable is the search engine (I assume it has one?)

Yep, it has search. It’s…okay but kind of primitive. It’s not slow, and if you’re searching for something that’s fairly unique (as far as keywords go), it does well. But if you’re searching something like an acronym where it shows up as a regular word in other entries, it’s a lot more hit or miss.

Yep, and I love it.

I’ve got a little Banana Pi M4 Zero (PiZero form factor but much more powerful and with 4 GB RAM) loaded up with, among other useful tools, Kiwix and the full Wikipedia dump. I just refreshed it with the 2026-02 full dump, so I’m caught up for the year. I’ve also got a lot of other offline docs loaded up (React, Bun, and the devdocs for several libraries I use) and it’s nice to have local copies of those instead of googling every time.

Surprisingly, the full ~130 GB Wikipedia dump works fine on a regular Pi Zero 2 with 512 MB RAM. I don’t know how ZIM works but it does work very very well.

I was surprised by that, too. When I went looking for a way to decode them with RTL-SDR, I assumed it wouldn’t be parsing the audio but a narrowband data stream. TIL also.

Edit: It does kind of make sense with it being AFSK encoded in-band, though, or maybe I’m just so used to it being that way. I always thought the screeches were there to demand attention (and also be something that headend equipment can pick up and respond to). So it’s interesting they’re doing double duty as both an unmistakable audio cue to pay attention as well as containing the actual alert data.

Plus there are NOAA stations all over the country rather than centralized like the time signal transmitters. It was probably cheaper to do it in band at that scale.

That’s what I’ve done for years. Makes managing things much easier, and I run multiple APs (all with the same SSID/PSK) and you can just roam to the best one. One upstairs, one downstairs, one in the weird dead zone in my office, and one on the back patio (it’s not hardwired and uses the mesh connection for uplink).

These are all old Aruba APs running OpenWRT but that’s the plan for this Cudy Model. I may pick up a few more and just replace all of my trusty but very old Arubas.

I bought this one last month when it was on sale for $39: https://www.amazon.com/dp/B0BRK3CYY3

Haven’t deployed it yet, but it’s fully supported by OpenWRT. I would only be using it as an access point, though. My router is a USFF Optiplex with an extra NIC and runs OpenWRT.

And the auto-submitting TOTP entry form where you’re apparently not allowed to make a typo. And obscuring the TOTP number like it’s a password or state secret.

I used to buy their stuff and use tuya-convert to flash Tasmota onto them. But they kept updating the firmware to lock that out, and I ended up returning a batch of 15 smart plugs because none of them would flash. They were too much of a PITA to try to crack open and flash the ESP8266 manually so I returned the whole batch as defective, left a scathing review, and blackballed the whole brand.