Ubuntu Laptop Battery Life

I have a Lenovo Thinkpad X1 Carbon 5th gen (2017). Its battery seemed to totally crap out this year, so I ordered a replacement battery, but right after clicking “buy,” I started poking around the power utilities on Ubuntu. I started to get the feeling that the battery wasn’t actually that much worse than when I first got it – utilities showed that the charge could reach 80% of what it used to. That made me wonder if there was some software-based issue that was killing my battery.¹

Battery life on Linux-based laptops has always been garbage: from the day I got the laptop, it would last 8+ hours when I booted Windows, but only a few hours on Ubuntu. To make matters worse, for the longest time my laptop would not sleep correctly. It still only does so intermittently; every so often I close the laptop lid and come back to find my laptop battery drained. I haven’t diagnosed what situations result in this, but you can imagine this is quite annoying and I have to keep everything saved and just expect that my laptop could be dead if I put it to sleep.

Anyway you might say “just use windows” but tbh it’s gonna be a nah from me dawg.² So here I am in 2021 still debugging the effing linux desktop.

Here’s what I learned:

1. sudo snap install auto-cpufreq TL;DR install this package, then sudo auto-cpufreq --install to install its daemon. Basically someone noticed that bare-minimum power optimizations were not being made, and wrote software to do simple things like turn off intel’s TurboBoost which chews through your battery. You can then run sudo auto-cpufreq --stats for a monitor that tells you nice things like what energy profile is being used (e.g balance_power) and what power driver is being used (e.g intel_pstate). This package alone improved my batterylife dramatically: I did a load test and even under load my battery life is back up to ~4 hours, up from 30min-1 hour prior to installing this package.
2. TLP is a super cool package you can use to optimize power on Ubuntu. TLP stacks with auto-cpufreq.
3. sudo apt install powertop « this package is like top, but shows which processes are waking up the CPU/GPU, what the battery discharge rate is, and what the total power consumed is.

The other thought I had was: maybe these tools will help me reduce my desktop’s energy footprint as well. I might update here with findings. My desktop tends to be doing some computionally intensive thing, whether it’s transcoding videos or processing Dark Forest zk-SNARKs.