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.

You can’t uninstall Play services once it’s installed (or if you’re on a stock ROM where it’s “baked in”), but you can disable it. Apps -> Set option to “show system” -> Google Play Services -> Disable

Will it crash as soon as I uninstall it?

No. However, you won’t be able to use most Google apps and RCS messaging and anything that relies on Google sign in or integrated Google Maps will not work.

You’ll also get hammered with “Google Play Services are unavailable” notifications from SO MANY APPS. Most of those, you can go into the app’s notifications and disable the alert for “Play Services Availability”. The only one I can’t disable on my phone is from Android Setup, but it only pops up once after a reboot.

Some apps depend on it more than others. Some will just complain that Play Services aren’t available but otherwise work just the same, but others will lose some functionality depending on how they use those services. For example, my bank app still works but complains Play Services isn’t enabled.

Most apps that depend on Play Services use it for notifications. So, with my bank app, I no longer receive transaction notifications. I can live without those, though, but some people may not be able to.

Can I have Android but not Play Services?

Yes. Most custom ROMs don’t include it by default or offer builds that exclude it.

Should I use MicroG? If yes, where do I download it?

You can only install MicroG or other Play Services features before booting into the phone for the first time (e.g. with custom ROMs), but you can’t just replace Play Services with MicroG.

https://ebooks.com/

They have a lot of DRM-free options and let you download a clean epub, but like with other stores, it’s up to the publishers whether (and/or when) they can sell them without DRM BS.

I like being able to download the epubs directly so I can put them on my Calibre-web instance and pull them to my Kobo or my phone or whatever I want to read on.

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.

I just use the webapp UI and don’t bother with the clients/extensions. Easy enough to just log in, copy/paste from there.

But yeah, the official client (and probably browser extension as well) would probably be forked if/when needed.

I use Vaultwarden

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.

Here’s a write-up I read not too long ago and answers many of your questions, though the author is mostly concerned with getting data access going. Short answer is yes, most will “just work” provided you use the correct modes and configs.

https://www.jeffgeerling.com/blog/2022/using-4g-lte-wireless-modems-on-raspberry-pi/

do linux apps working as contact list/dialer/SMS receiver/sender exist?

Those all fall under what’s called the IMS (IP Multimedia Subsystem) and is often problematic implementing in open source. If I recall, Ubuntu Touch has a (mostly?) working IMS implementation but I don’t recall if it’s universally functional or limited to specific devices/carriers. Some WWAN cards will allow calls/texts, but those are usually in “3G” mode which is rapidly disappearing as carriers switch to VoLTE or VoNR/Vo5G (which are basically just fancy VoIP).

If you’re willing to forego traditional carrier voice/messaging, you can use any number of messaging apps that work on Linux and/or combine that with a 3rd party VoIP provider for PSTN calling/phone number and SMS/MMS. Just don’t expect to get RCS messaging going; even on Android proper, you’re limited to Google Messages only.

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 never really got the humor there, lol, but I’m lamenting the loss of 80s TV because I had a lot of good Golden Girls posts since I’m finally watching it for the first time.