The cause of "spicy pillow"

Lithium‑ion cells swell due to:

High sustained charge levels (95–100%)

High temperatures

High charge/discharge cycles

Aging cells

Faulty charge controllers

Linux power management is still behind Windows on many laptops with less aggressive CPU idle states, higher baseline power draw, dGPU not fully powering down, fans aren't controlled as tightly, and background processes not optimized for mobile hardware.

Higher temps equate to faster battery degradation which we see on Framework laptops, ThinkPads, System76 laptops and ANYTHING nvidia! People on Linux are frequently disclosing 10-20°C higher idle temps compared to Windows.

Windows OEM utilities (Lenovo Vantage, Dell Power Manager, HP Command Center, etc.) cap charge at 80%, Reduce charge speed, and optimize for longevity. Linux Does nothing unless you manually enable TLP, power-profiles-daemon, or vendor-specific kernel modules. (Enter: SkiLl iSsUe! comments)

A laptop that would sit at 80% on Windows may sit at 100% 24/7 on Linux, which accelerates swelling. *tip: Even if not for safety, your battery will last longer by keeping it between a recommended 20-80% or 15-85%. -Linux doesn't care how long your hardware lasts, or how safe it is; your OEM does! *Removing OEM bloatware can help with battery health though.

Windows has ACPI tuned by OEMs, battery calibration tools, thermal tables optimized for Windows, and vendor drivers that manage charging curves. Linux often uses generic ACPI, reverse‑engineered drivers, incomplete charge‑limit support, and less accurate battery reporting leading to overcharging, poor thermal response, and batteries sitting at high voltage longer.