I've collected some hacks from our kernel team and tested the idle time on battery on my Librem 5 Birch - got almost exactly 6 hours while staying at 38°C the whole time. Not that long ago it struggled to reach 3h and stay under 60°C - and they're not done yet! :D #librem5#imx8m
Oh, and that's of course on the 2000mAh battery. The final model is going to have a 3600mAh one :)