Turning a Raspberry Pi 5 into a pocket Linux server powered by a power bank

At a glance:

• Ayush Pande turned a Raspberry Pi 5 into a portable Linux server running off a 20,000 mAh power bank, lasting over 7 hours with Docker containers and lightweight tools.
• The setup uses Raspberry Pi OS Lite, Docker with rootless mode, and a smartphone hotspot for networking — no LTE HAT or extra hardware required.
• Deployed tools include Pairdrop, BentoPDF, Vert, IT-Tools, barebones Debian and Arch Linux containers, and Dockhand, all accessed via Termux on an old phone.

The ARM experimentation behind the project

Ayush Pande, a PC hardware and gaming writer, had already put most of his x86 devices to work on other DIY projects, so he circled back to experimenting with ARM-based single-board computers. His experiments went beyond typical tinkering: he'd been running a range of lightweight large language models on his SBCs, finding that sub-4B models ran surprisingly well and that clustering boards together could even handle 9B LLMs — though the token generation rates were painfully slow. That hands-on experience with LLM-hosting on ARM boards sparked a "terrible idea" that turned out to be surprisingly practical: what if he turned an SBC into a pocket Linux server that runs off a power bank?

After narrowing down the list of devices that could work without requiring dedicated Wi-Fi or storage adapters, the Raspberry Pi emerged as the only single-board computer that fit the bill. The Raspberry Pi 5 became the centerpiece of the build, and Pande set out to prove that the board could function as a truly portable Linux server.

Powering the Pi from a power bank

The Raspberry Pi 5 has demanding power requirements — the Raspberry Pi Foundation recommends a power supply capable of 5V/5A — while the average power bank tops out at 5V/3A. Pande initially assumed a mere power bank wouldn't cut it, but when he plugged his 20,000 mAh power bank into the RPi 5's Type-C port, the board's LED flickered to life. It wasn't a full-powered setup by any means; demanding tasks would be off the table, but for lightweight server work it was enough to get started.

To keep the resource drain minimal, GUI-laden distributions were ruled out. Pande considered DietPi but ultimately chose Raspberry Pi OS Lite because its quality-of-life tools outweighed the benefits of DietPi for this project. Once the OS was configured, he set up OpenSSH Server and established an SSH connection using PuTTY.

Docker containers on a pocket server

Full-fledged virtual machines were off the table — even CLI VMs would buckle under the load and drain the power bank faster than necessary. Instead, Pande pivoted to Docker. He followed the official Docker guide to set up the container runtime, enabling rootless mode for an extra layer of security. The containerized approach proved ideal for minor computing experiments on the go.

The first tool he deployed was Pairdrop, a file-sharing utility accessible via web browser. After confirming it worked, he moved on to spinning up BentoPDF, Vert, IT-Tools, and a range of other FOSS tools he might need while away from his primary setup. For tinkering environments, he created barebones Debian and Arch Linux containers, then wrapped up with a Dockhand instance. None of the services showed slowdowns during normal use, though they weren't heavyweight applications to begin with.

Networking with a smartphone hotspot

One of the trickier parts of the build was networking. Pande didn't have an LTE HAT on hand, so he couldn't simply slap Tailscale on the board. Carrying a device that relied on Wi-Fi for access also wasn't practical for a truly pocketable server. Instead, he paired the Raspberry Pi with his smartphone's hotspot by running sudo nmcli in the terminal to connect to the phone's network.

However, his smartphone couldn't access the Raspberry Pi's terminal without dedicated tools. He installed the Termux APK on his old phone and ran pkg install openssh to give it SSH capabilities. Within seconds, the phone served dual roles: it provided internet access to the Pi's networking stack and doubled as a makeshift debugging tool for when things went wrong. This setup eliminated his need to rely on Tailscale for on-the-go access to self-hosted services.

Battery life and real-world use

To test endurance, Pande left the Raspberry Pi and all its Docker-based services running on the 20,000 mAh power bank. The board lasted well over 7 hours — a surprising result for a cheap power bank powering an underpowered SBC. The services themselves showed no slowdowns during that window.

Pande notes that he typically relies on Tailscale to access his home lab while traveling, but the power-bank-based Raspberry Pi setup could fill a gap for those rare occasions when internet speeds are poor. The idea of carrying a pint-sized server is appealing enough that he's considering bringing it on trips. For anyone running lightweight LLMs or self-hosted tools who needs a portable fallback, the build demonstrates that a $60 board and a power bank can go a long way.

Raspberry Pi 5 at a glance

• CPU: Arm Cortex-A76 (quad-core, 2.4GHz)
• Memory: Up to 8GB LPDDR4X SDRAM
• Operating System: Raspberry Pi OS (official)
• Ports: 2× USB 3.0, 2× USB 2.0, Ethernet, 2x micro HDMI, 2× 4-lane MIPI transceivers, PCIe Gen 2.0 interface, USB-C, 40-pin GPIO header
• GPU: VideoCore VII
• Starting Price: $60