08-28-2022, 05:43 PM
(06-11-2021, 10:34 AM)dsimic Wrote: The good news is that it should be possible to tweak the desired maximum battery charge level by adjusting the BQ24171's target battery voltage, which is described on page 16 of the BQ24171 datasheet. However, there are some bad news:
- The target battery voltage is configured using a couple of resistors on the PCB, so those would need to be replaced.
- Reducing the target battery voltage and leaving the maximum battery charging current unchanged would result in further reduction of the maximum power that can be taken from any of the two power inputs, and the battery would even more often be used as the power source for the laptop, even if it's connected to a charger.
- The above-described issue could be mitigated by increasing the maximum battery charging current at the same time, but unfortunately there isn't a lot of room for that. However, there might be a sweet spot.
By the way, after further analysis of the way BQ24171 is used in the PineBook Pro, I'm pretty sure that increasing the maximum battery charging current is the only doable way for increasing the maximum power draw from any of the two power inputs. All components in the power path should be able to handle a 15% to 20% increase of the maximum battery charging current; combined with additional cooling applied to the BQ24171, this should be a win-win hardware modification.
Of course, I still need to re-evaluate the entire approach a few more times, so we definitely stay on the safe side with such a modification.
This sounds very promising. I recently purchased the pinebook pro and got the NVME adapter for it. my NVME only uses 3W max and I still have problems with it when the battery gets down to around 20%. Is there a way to increase the amount of power taken from the battery as well?
