I have a framework. Battery life varies between 2 (physics simulation + opengl rendering), 3 (zoom meetings on Wayland), 5 (netflix on firefox), 7 (local streaming with mpv), 8 (casual browsing with an adblocker), and 12 (coding/reading in a TUI) hours.

Note, I use sway but don't notice much of a battery difference on gnome or plasma.

Thanks for ordering and we hope you like it! That is something we will likely do in the future, but in the meantime, there are a few good threads in our community where people walk through the optimizations they are testing: https://community.frame.work/t/performance-cpu-temp-and-batt...

I'm kind of surprised battery cells aren't one of the kinds of usbc case modules you can get out of the gate. Obviously they'd be a bit limited in mAh but tbh a lot of the time I'd probably be willing to sacrifice 2 or even 3 of the 4 modules for battery if I'm actually on the go.

(I kind of suspect you might be limited to one though, assuming the power delivery controller can only really handle one external source of power)

Would it be enough to be worthwhile at all though, even ignoring the cost of the control circuitry? (and what's the laptop going to do when it sees 5 power sources? How does it know not to charge one depleted battery module from another?)

Some thinkpads already come with two batteries. The program tlp knows how to handle charging and discharging two batteries very well. It just does them one at at time in a given order of priority.

Sure, but these modules are about half the size of a phone, even all four would be considerably less capacity than a full-size spare.

Yep I have a thinkpad T580 with two batteries and it works flawlessly on Fedora and has for the 3 or 4 years I've owned it.

yeah, definitely concerns there. I honestly don't know. I think it'd be interesting if they considered a single "long bay" as an option on future models that could accommodate a few battery cells or something else like an extra m.2 slot.