08-17-2021, 04:15 PM
I'm not even slightly hostile to user configurability. I think that's a very important thing here. But clearly it wasn't easy to add to the Pinebook Pro, because they didn't include it. The reference design they were following probably used that simple resistor-programmed charge controller chip, and reworking the entire board to incorporate a more sophisticated PMIC probably wasn't really on the table. I think that user configurability is absolutely better than this in every way, but the bottom line is that when they designed the Pinebook Pro, they had to choose one charge profile to bake into the hardware that could never be changed again without very fine soldering, and I strongly believe that they picked one that sacrificed too much battery lifetime for only small returns in battery capacity.
What I'm asking for here is really not much. Most users probably would not even notice the change, because at the end of the day, we wouldn't be going back to the NiMH days; we'd be going back to the early-2010s lithium-ion days when cells were usually rated to last a decade or more. The cells made nowadays are also mostly just better than they were back then, so we wouldn't even have to go all the way back to older capacity figures, just somewhere in between. My current assumption is that Pine64 has not made any attempt to optimize battery capacity vs. longevity and has simply adopted the parameters from the reference design. I would like to change that, and take a more critical approach to selecting these values. The current situation is not a reasonable medium, and is actually somewhere near the furthest extreme of longevity sacrifices for diminishing returns in capacity that vendors can get away with without attracting bad press.
Ultimately, the current charge parameters used on the Pinebook Pro are basically self-defeating, because they serve neither a need for longevity nor a need for runtime. I got mine along with the early-adopters, going on two years ago now, and by now, my battery runtime has already decayed substantially. Had the parameters been set only slightly lower and yielded, say, 90% of the nominal design capacity, I would experience considerably longer runtimes now. While the initial runtime would have been slightly shorter, it would have decayed much more slowly, and remained closer to its original levels by now. The only time you'd actually want such an overcharged battery is if you were planning on throwing the battery away in a year anyway, and I don't think many people bought a Pinebook Pro with that intent.
What I'm asking for here is really not much. Most users probably would not even notice the change, because at the end of the day, we wouldn't be going back to the NiMH days; we'd be going back to the early-2010s lithium-ion days when cells were usually rated to last a decade or more. The cells made nowadays are also mostly just better than they were back then, so we wouldn't even have to go all the way back to older capacity figures, just somewhere in between. My current assumption is that Pine64 has not made any attempt to optimize battery capacity vs. longevity and has simply adopted the parameters from the reference design. I would like to change that, and take a more critical approach to selecting these values. The current situation is not a reasonable medium, and is actually somewhere near the furthest extreme of longevity sacrifices for diminishing returns in capacity that vendors can get away with without attracting bad press.
Ultimately, the current charge parameters used on the Pinebook Pro are basically self-defeating, because they serve neither a need for longevity nor a need for runtime. I got mine along with the early-adopters, going on two years ago now, and by now, my battery runtime has already decayed substantially. Had the parameters been set only slightly lower and yielded, say, 90% of the nominal design capacity, I would experience considerably longer runtimes now. While the initial runtime would have been slightly shorter, it would have decayed much more slowly, and remained closer to its original levels by now. The only time you'd actually want such an overcharged battery is if you were planning on throwing the battery away in a year anyway, and I don't think many people bought a Pinebook Pro with that intent.