did a first test running Reform 2 from batteries with display on, medium brightness, all cores on, GPU in use by the compositor, low load, mPCIe WiFi active, NVMe SSD active (logging), keyboard backlight enabled, no powersave features in use: 292 minutes until safety switchoff.
so almost 5 hours. i believe this can be optimized with powersave strategies but i think it's quite ok already.
currently turns off if a cell reaches 2.6V. it could go a bit lower, but i don't think for much gain.
@mntmn If I were you, I would try running PureOS as packaged for the Librem 5 on the reform (I'm not sure how possible this is). To my understanding phosh, is supposed to work in a convergent way so it might be suitable for desktop use. More importantly, they have been doing a bunch of work to reduce power consumption on the same imx8m SOC. So it would be interesting to see what your runtime would be with their modifications on board.
@leimon i'd rather take a look at those modifications and understand them in isolation before moving away from debian