Pi Cooling, Cases & Power

The Pi 5 throttles at 85°C and will hit it under sustained load with the stock case. Always plan for cooling. Power-wise the Pi 5 wants a 5V/5A USB-C PD source — older 3A bricks will work but the Pi will warn and disable some USB power. For UPS HATs and PoE HATs see HATs & Accessories; for fleet provisioning that depends on reliable power see Pi Fleet Management.

Cooling: the Pi 5 specifically needs it

• ★ Official Raspberry Pi 5 Active Cooler — heatsink + PWM fan that clips on; ~$5; managed by the Pi 5 firmware (fan ramps with temp). The "you should always buy this" accessory. Sufficient for almost every workload short of constant-100%-CPU.
• ★ Argon ONE V3 (Argon40) — full aluminum case + active cooler + GPIO breakout + power button + side-routed ports. ~$30. The "I want it to look like a finished product" pick. Includes M.2 NVMe variant.
• ★ Flirc Raspberry Pi 5 Case — passive aluminum case that uses the case body as a heatsink. Silent. ~$25. Good for moderate workloads where you don't want fan noise.
• Pimoroni NVMe Base + Active Cooler — combine NVMe storage with the official cooler; clean stack.
• Geekworm "Armor" cases — passive aluminum cases; good thermal mass; ugly aesthetics but cheap.
• 52Pi ICE Tower for Pi 5 — overkill heatpipe tower cooler; effective but tall.

Cases without active cooling (only with light loads)

• Official Pi 5 Case (red/white) — the bundled-with-kits case. Includes a small fan in 2024+ revisions. Acceptable for light workloads (Pi-hole, single Home Assistant) but not for sustained CPU.
• Pimoroni Pibow — layered acrylic; classic, cute, does not cool — fine for Pi 4 but skip for Pi 5 unless you add a heatsink.
• 3D-printed cases — search Printables / MakerWorld for "Pi 5"; many include cooler clearance.

Pi 4 / Pi Zero cooling

• Flirc Pi 4 Case — same passive-aluminum approach; silent.
• Pimoroni Heatsink Case (Pi 4) — passive, decent, ~$15.
• Pi Zero 2 W heatsinks — Zero 2 W can throttle under sustained load; a $1 stick-on aluminum heatsink fixes it.

Power supplies for Pi 5

• ★ Official Raspberry Pi 5 27W USB-C PD Power Supply — the right answer; signals 5V@5A to the Pi 5 firmware. ~$12.
• Generic USB-C PD chargers (≥5V/3A) — work but Pi 5 will throttle USB-attached devices unless you usb_max_current_enable=1 in /boot/firmware/config.txt. Use a name-brand PD charger that actually does PD negotiation (Anker, UGREEN, Apple).
• USB-C PD trigger boards — for "use my laptop charger to power the Pi"; useful if you have spare 65W laptop bricks.
• ★ Pi PoE+ HAT (official) — power + Ethernet over one cable. See HATs & Accessories.

Power supplies for older Pis

• Pi 4 official 15W PSU (USB-C, 5.1V/3A) — the right answer.
• Pi Zero / Zero 2 W official 5V/2.5A micro-USB PSU — same.
• Beware "5V chargers" with under-rated voltage — long, thin USB cables drop voltage; the Pi will under-volt and slow down silently. Check vcgencmd get_throttled if behavior is weird.

UPS / battery backup

• ★ PiSugar 3 / 3 Plus — LiPo-backed UPS HAT; clean shutdown on power loss; ~$30-50. See HATs & Accessories.
• Geekworm UPS HATs (X1202 for Pi 5, X728 for Pi 4) — 18650-cell-based, hot-swap.
• Waveshare UPS HAT B/D/E — variants per Pi family.
• Argon BLSTR — Argon's UPS module that pairs with their cases.
• External small UPS (CyberPower CP425SLG, APC Back-UPS BE600M1) — boring, works for a stack of Pis + switch + modem; almost always the right answer for a homelab — see Homelab. USB cable to the Pi for apcupsd / nut graceful shutdown.

Pi 5 RTC battery

The Pi 5 has an on-board RTC powered by a tiny rechargeable battery via the official J5 connector. Foundation sells a Panasonic ML2020 + harness for ~$5; otherwise time will reset on power loss without internet (NTP).

Heat dissipation in cluster / rack scenarios

• Cluster boards like the Turing Pi 2 expose CM heatsinks to top airflow — case fans matter; the official RK1 heatsinks are required, not optional.
• DeskPi RackMate units with closed sides need a rear exhaust fan for sustained loads.

Power monitoring

• ★ vcgencmd measure_temp / vcgencmd get_throttled — built into Pi OS; the first thing to run if a Pi is acting weird.
• vcgencmd pmic_read_adc — Pi 5 only; reads internal voltage rails. Useful for diagnosing under-voltage.
• ★ Smart plugs that measure watts (Tasmota, Shelly Plug US/EU) — see Self-Hosted Automation. Stick one between PSU and outlet to graph Pi power draw in Home Assistant.

Cable / connector reality

• Use the included USB-C cable with the official PSU. Random USB-C cables vary wildly in resistance.
• Right-angle USB-C adapters for tight enclosures — keep cable length short.
• Locking USB-C cables for "production" deployments where someone might bump the cable.

License / pricing

All products listed are commercial hardware purchases. Software (vcgencmd, apcupsd, nut) is FOSS (BSD / GPL).

Pick this if…

• Default Pi 5 cooling: Official Active Cooler. Just buy one with every Pi 5.
• Want a polished case + cooling: Argon ONE V3.
• Silent passive cooling: Flirc case.
• Default Pi 5 PSU: Official 27W PSU.
• Power + Ethernet one cable: Official PoE+ HAT.
• Always-on Pi, want graceful shutdown on outage: small external UPS (CyberPower / APC) — boring, works. PiSugar if portable.
• Pi 5 keeps its time across power loss: install the RTC battery.
• Pi acting weird: vcgencmd get_throttled first.