Poor battery life on ThinkPad T420

Question

I recently tried to use elementary OS on my ThinkPad T420. Most of the hardware worked just fine out of the box: wifi, sound, graphics, etc. However, battery life on elementary OS has been very, very bad! It lasts about an hour at most. I have installed and enabled TLP, but it doesn't seem to make any difference.

The same laptop on Solus, Ubuntu or Mint lasts around 3 hours, and on Windows around 4 hours.

I tested the system by browsing the web on Firefox/Chromium, some light app installing, and general OS exploring. Nothing demanding has been ran when I tested the battery life.

Any thoughts?

Answer 1

I've had issues with battery life before, and every time it turned out to be a faulty install. Try reinstalling the OS and it should fix the issue. Elementary doesn't use any different drivers battery-wise than Ubuntu and if you have no problems on there, you shouldn't have any problems on elementary either.

Answer 2

thanks for the tip.

I reinstalled it and the issue remains the same. I left powertop running for a while, check the info below:

PowerTOP 2.8      Overview   Idle stats   Frequency stats   Device stats   Tunables                                     

The battery reports a discharge rate of 11.2 W
The estimated remaining time is 1 hours, 9 minutes

Summary: 767.5 wakeups/second,  0.0 GPU ops/seconds, 0.0 VFS ops/sec and 21.2% CPU use

                Usage       Events/s    Category       Description
             1993 rpm                   Device         Laptop fan
             50.2 ms/s     139.7        Process        /opt/google/chrome/chrome --type=renderer --field-trial-handle=14154079299553752411,6608151803463361335,131072 --se
              4.3 ms/s     132.1        Timer          hrtimer_wakeup
             16.6 ms/s      83.4        Process        /opt/google/chrome/chrome
             11.8 ms/s      75.6        Process        /opt/google/chrome/chrome --type=gpu-process --field-trial-handle=14154079299553752411,6608151803463361335,131072 -
              8.5 ms/s      60.1        Process        gala
              2.1 ms/s      61.4        Timer          tick_sched_timer
             15.3 ms/s      54.8        Process        /opt/google/chrome/chrome --type=renderer --field-trial-handle=14154079299553752411,6608151803463361335,131072 --se
             77.9 ms/s       7.7        kWork          intel_atomic_commit_work
              1.1 ms/s      21.6        Interrupt      PS/2 Touchpad / Keyboard / Mouse
              7.8 ms/s      16.5        Process        /usr/lib/xorg/Xorg -core :0 -seat seat0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch
            213.5 µs/s      19.7        Interrupt      [28] iwlwifi
              1.5 ms/s      16.9        Interrupt      [25] i915
            171.6 µs/s      13.6        Process        [rcu_sched]
              1.5 ms/s       9.5        Interrupt      [7] sched(softirq)
            343.8 µs/s       8.7        Process        [irq/28-iwlwifi]
            221.0 µs/s       7.1        kWork          ieee80211_iface_work
             48.7 µs/s       6.9        kWork          console_callback
            105.9 µs/s       5.9        Process        [i915/signal:0]
            410.1 µs/s       3.9        Process        /usr/sbin/acpid
             70.9 µs/s       2.9        kWork          iwl_bg_run_time_calib_work
              1.6 ms/s       1.7        Process        /opt/google/chrome/chrome --type=renderer --field-trial-handle=14154079299553752411,6608151803463361335,131072 --se
            428.2 µs/s       2.0        Process        wingpanel
            385.4 µs/s       1.5        Process        plank
             20.6 µs/s       1.5        kWork          intel_atomic_helper_free_state_

            297.6 µs/s       0.8        Process        /usr/lib/x86_64-linux-gnu/bamf/bamfdaemon
              1.4 ms/s       0.4        kWork          disk_events_workfn
             20.8 µs/s       0.9        kWork          iwl_pcie_rx_allocator_work
              1.0 ms/s       0.4        kWork          i915_gem_idle_work_handler
            187.5 µs/s       0.7        Interrupt      [4] block(softirq)
            309.1 µs/s       0.6        Process        pantheon-terminal
            264.5 µs/s       0.7        Process        /opt/google/chrome/chrome --type=renderer --field-trial-handle=14154079299553752411,6608151803463361335,131072 --se
             16.8 µs/s       0.7        kWork          vmstat_shepherd

By the time I left it run and posted this (10 min of usage), I lost around 15% of battery :(

Answer 3

This could easily depend on whether your model has an Optimus GPU installed - power management for that's notoriously poor.

• If you do, then you'll need some tweaks to allow it to save power (http://www.thinkwiki.org/wiki/Switchable_Graphics)

Otherwise, look to the usual suspects for a T-series Thinkpad; TLP or Thinkfan. Go & check out thinkwiki for the T420 it's your go-to place for Thinkpad tips.