[Magisk] MrFrizzy:
OnePlus 8T here on 11.0.8.13 firmware.

Long time user of Battery Charge Limit on both this phone and my prior OnePlus 5T, had virtually zero issues with that working. Since the 8T can charge at ridiculously high rates (65W with the factory charger or 27W with USB PD), I want to limit the charging to extend the battery lifespan. I got over 3 years with my 5T and never really had a problem with the battery life, but I always used a non-factory charger (7.5W) and never charged over 80% (only killed the battery on a few occasions too). My hope was to achieve something similar for my 8T.

With AccA running version 202010150 of Acc, I have setup charge limits (80% limit, 70% start), voltage and current limits, and tried battery idle mode. Of those, only the voltage and current limits work. Of the control files that work, none of them fix the charging past 80% issue, not even setting it to the same one that works for Battery Charge Limit (battery/charging_enabled 1 0). I have had to re-enable Battery Charge Limit to get the phone to stop charging at 80%. I also find that if the phone is not charging, USB audio routing stops working. If I uninstall AccA then remove Acc via Magisk, the audio routing works as expected. The 8T doesn't have a 3.5mm port so a USB audio/power splitter is what I use to charge and have audio out simultaneously. So, this is really only an issue if I am using a USB DAC on-the-go rather than in my car or home. Yes, I could use bluetooth, but until you get to expensive equipment, the usual bluetooth codecs suck in terms of latency and compression, so I prefer a wired connection.

I just updated Acc to the latest 202107281, so we'll see if anything works better than before.

EDIT:

Seems that the charge limits work with 202107281, but am having issues with the voltage limit not working now (haven't drained my battery enough to test the current limit yet). Battery idle mode does not work still, though it does say that the kernel supports it. I'll probably try removing the app (AccA) and do some testing with just the CLI, see if that helps with anything.

EDIT 2:

Didn't uninstall the app yet, but can confirm that the voltage and current limits are indeed working (had to reset the values, re-enter them, and reboot the phone before they worked). The battery idle does not work. So, the two key features for me are working and the two nice-to-have features are not working, yet.

Now, I have more details on the audio routing issue. If I unplug the charging cable while between 70-80% (my start/stop limits), the audio routing works fine until the battery hits 70%. As soon as that happens, the audio routing stops working and there is the Android notification for "charging this USB device" (or something like that) that gets stuck in my notifications even if I unplug the charge/audio splitter adapter. Plugging the charger back in does not fix the audio routing even after the phone gets back between 70-80%; only rebooting the phone seems to get the audio routing working again.

EDIT 3:

All of a sudden, the battery idle mode is working. I didn't change anything, but it is working on two different chargers. The battery charges to 80% (my limit) and then sits there "not charging" with 0mA being the current. Before it would hit 80% and switch to "discharging" until the battery dropped to 70%. Now, charging still happens if I reconnect the charger while it is still above 70% (the resume charging limit).

The only thing I can think of is that I did have the audio routing problem today. The charger was unplugged from the audio/charger splitter for long enough that the phone got into that "charging this USB device" message. Plugging the charger back in did not fix the issue so I unplugged the splitter and plugged it back in which did the trick (normally I have to reboot the phone). Perhaps that is what caused things to work, perhaps it was just a coincidence?

Side note: the logs show "battery/op_disable_charge 0 1 battery/input_suspend 0 0" being used as the switch. I have tried that switch manually in the past, but I don't recall if it was after updating to 202107281.