Charging optimization (80% charge limit) recalibration with Android 15 QPR2

DeletedUser10

Charging a phone battery is simple, isn't it.
When you charge it are you relying on the inbuilt protection circuitry of the battery, the operating systems software, the circuitry of the plug charger or even the circuitry of the wireless charger, which is it? Which one controls the charging or do they all have a hand in it. Do you turn off the phone to charge, probably not. So with so many variables in such a simple task is it any wonder a battery in a phone having being pushed to its limits every day, powering a phone doing things a phone was not meant to do, but could do occasionally, fails. I just don't see that charging a battery to 80% instead of 100% and abusing it in a phone makes it last longer. Charging it properly and looking after it will keep its performance as expected.

Lurker

My 6a is displaying very inaccurate battery levels.
I either reboot or do a shutdown/restart each morning. Today, my battery was at 68%. After the restart its at 53. I charge to 80. A half hour ago I did another shutdown just to see what happens. On restart the battery is showing 93.
Same thing yesterday except the battery started at 68 and was at 44 after the shutdown.
I'm turning of this garbage option.

other8026

Lurker that doesn't sound normal and there may be something else going on.

Lurker I'm turning of this garbage option.

I doubt that this is related.

GrapheneOS

Lurker You battery is likely failing. It has nothing to do with the option.

Lurker You can replace the battery without replacing the phone. That's expected if a phone is used as a daily driver for 5 years from launch or 7 years from launch. Replacing the battery one or twice is expected. There are official replacement kits for Pixel batteries sold through iFixit.

Kai1

Since the last 2 updates my 8a is charging all times to 100%, I've tried to turn off and turn on the feature and then turn off my mobile, same without turn off it, my device is up to date but it still charges to 100%.

I already charged it at least 10 times but it doesn't stops at 80%.

other8026

Kai1 have you let it charge all the way to 100%? Also did you leave it for a little while at 100%?

ToolTimeTim7

other8026 leave if for a while at 100%? How long? If this is required to finish recalibration (and therefore actvate the 80%) there should be a Notofication or something. How else is the user supposed to know that this is required?

Lurker

other8026

I fully agree this isn't normal - hence my comment.

Edit: I just did a shutdown/reboot with the battery at 94%. After the restart 89%.
You are correct. Doesn't seem to be related.
Frak, the battery charge cycle is only at 261. I was hoping to get a couple more years out of this phone.

Lurker

GrapheneOS

I doubt if failing batteries show a higher level after the reboot. Just this morning I had the phone plugged in using battery optimizer. The battery was holding at 80%. After I did a shutdown/restart the battery was showing 85%.
Also, this phone for 2.5 years old and it's charge cycles are at 261. Likely the battery is degrading but this behaviour only started recently when all our phones had to fully charge to recalibrate.

Grapi

My last experience with Pixel 8a: after the calibration charging till 100% I got that shield, but after approx. 80 minutes (according to AccuBattery log) the phone began discharge from 100% down, as if it was no bypass anymore, however the shield icon was still present. So the shield icon was there, the charger was connected to the phone, but actually no bypass and no charge at that time.

Additionally I noticed in general enormously high battery consumption on my both Pixel 7a and 8a after the last update.

GrapheneOS

Grapi

Additionally I noticed in general enormously high battery consumption on my both Pixel 7a and 8a after the last update.

You have an issue with your apps, network or configuration which you're attributing to OS updates without evidence for it. Battery life is not negatively impacted by recent updates for our overall userbase.

ToolTimeTim7

Grapi Are you sure that a bypass is the intended meaning of the shield? My Interpretation was "I protect the battery by not charging it anymore", but I may be wrong.

ToolTimeTim7

OK - its actually written in this threads first post, but not in the UI (it should really be written in the UI!)
If you leave charging at 100% until the shield icon appears in the charging icon, it does work - at least it did for me yesterday.

graphoux

@GrapheneOS would bypass charging work with a USB-A 2.5W charger ? Or does it need a PPS charger to work ?

GrapheneOS

graphoux You need proper USB-PD fast charging for it to work properly. Unclear what it will do if you don't.

tomz

P7. with latest updates.

My battery last only 3 hrs after reaching 80% when i use it. last about 8hrs if i dont touch it. Battery indicator reads, last 1day 8hrs. Thats over reach for sure; not going to realistically happen. My battery cycle count is 696 (says battery is healthy). Sometimes i start charging it when it reaches 10%. I got this device Aug 2023. Not sure if i should trade it in on Aug 2025 or keep it, given my battery situation.

TrustExecutor

GrapheneOS
Don't you mean USB-C PPS where the device and charger can more fine grained negotiate on the voltage level?

Does the shield icon mean battery bypass is active or just that charging is limited, or both?

xse

Hey,

I'm having an issue with that feature on a Pixel 8a following the latest stable release channel, it seemed to work at first - i recall one time when the phone stopped charging at 80%
But since then it keeps acting as if this feature was disabled and basically never stopped charging at 80%.
I thought this was due to the calibration mentioned near the setting button at first but many charge cycles have passed since and yeah it doesn't work.

I'm mostly using an old 5V/550mA charger but can also replicate this issue with the PD 20Watt one sold with the phone.
Beside rebooting and turning the feature on and off again which did not work, I'm not sure what i can do.
Since this is quite recent I'm sure it'll get fixed in future releases but still wanted to mention it.
Anyway, have a good day!

GrapheneOS

xse You need to let it charge to 100% and sit there until it shows the shield icon.

iii

Is there a list of chargers confirmed to work with bypass charging?

I ask because I am running GrapheneOS 2025031400 on a Pixel 6a, but I still observe the behavior I mentioned here: https://discuss.grapheneos.org/d/18713/5 . My Pixel 6a shows "NOT_CHARGING" for 3 minutes, then "CHARGING" for nearly a 1 full minute, then repeat. I would guess that this is far too frequent if bypass charging is working as expected.

I have tried using the 18W OEM charger and cable and using a 20W Anker brick and cable that is Power IQ 3.0, which claims to be compatible with QC 3.0 + PD 3.0 + Power IQ 1.0. Both chargers/cables show the "NOT_CHARGING"/"CHARGING" behavior.

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