Battery preservation settings

area51

Apologies in advance if this has been covered.
I installed GOS on a brand new Pixel 8a out of the box. Its my third or 4th iteration of the OS which I love.
I enabled the 'charge to 80% only' setting to try and maximize my battery life over time. The setting is supposed to charge to 80% normally but fully charge up to 100% every week or two. In the time I've been doing this (probably 5 or 6 weeks) it has not once charged to the maximum, every morning it's sat there at 80%. It's not a problem, 80% is plenty for a day or two for me but I'm interested in why this might be or to know if I need to do anything differently. Thanks.

de0u

area51 The setting is supposed to charge to 80% normally but fully charge up to 100% every week or two.

How often it decides to run up to 100% is up to it, and probably depends on the usage pattern. I suspect it's best to let it do its thing.

Quantum

I do fear the battery recalibration(it going to 100%) is broken again. I have two phones running GOS, both haven't reached 100% in a good while now. Way longer than before.

I was actually contemplating making a post asking others if they've reached 100% recently.

1qkv9ddu3so2irvz

Quantum
I've been asking this myself as well. My 6a hasn't gone up to 100% for many weeks now. Is it because I have it on the charger all the time when I'm at home and therefore don't produce that many cycles?

Quantum

1qkv9ddu3so2irvz Not that I know this, but I'm guessing it makes a calculation per time you connect the charger. Or it bases it off the cycle count as that is more reliable maybe.

Either way, it should have calibrated based off how often it used to do it before.

area51

From what others have said it maybe isn't working (is no-one has had a 100% charge in a while)

router99

Has battery technology not improved in 20 years so as to not have an issue with being charged past 80%?

de0u

router99 Has battery technology not improved in 20 years so as to not have an issue with being charged past 80%?

I believe float-charging lead-acid batteries at 100% is still as good for them as it was 20 years ago, and I believe holding a lithium-ion battery at 100% is still roughly as bad now as 20 years ago.

Chemistry usually doesn't change all that fast.

DeletedUser495

de0u well, well, battery percentage can be/is designed that 100% is not really 100%, or is it? Chemistry may not change but battery management surely does.

WestQuester

I've been running GOS since end of May. Never charged to 100% yet. Pixel 8.

pixelfairy

Mine charges to 100% when turned off. This could be a software thing. It still went to 100% once in a while when it was running stock pixel android.

Quantum

pixelfairy Pretty sure the limit only works when the phone is on.

If I remember correctly these types of batteries are stored at 50-60%. Why even code a limit to 80% if it has no merits?

Yes the phone stops charging at 100%, but I've not seen it being mentioned it pass-through charges natively at 100%. I will assume it'll spare my battery wear if i use the 80% limit and use the pass-through charging for as long as I can each time, rather than going to 100%.

Quantum

I've just seen in the setting for the 80% limit it says "The phone charges to 100% once or twice PER week to accurately rapport the battery level"

So its hella broken

xxx

Quantum charges to 100% once or twice PER week

That would be far to often for a new battery. I think firmeware is involved too.

Quantum

xxx I do agree that seems often. Though it does sort of give an example of how often one should except it.

It's been many weeks since it last happened...

router99

Battery charging neuroticism. I haven't seen any solid proof that newer phones benefit from cutting off charging at 80%. If there is any issue with charging past 80%, I'm sure the engineers have figured out how to deal with it so you don't have to do this.

Quantum

router99 ~~By that logic do I reduce my overall battery longevity by 20% then as it's based off cycles?~~ Nevermind me being stupid

I think we can all agree that these things are all bad things for the battery;
Age
Heat(heavy use, fast charging etc)
Discharging the battery to 0%

Without getting into all the contradicting links out there. Why would EV manuals instruct users to primarily charge ones car to 80%. Why would Google and Apple both introduce a 80% limit or adaptive charging to keep the phone away from 100% for as long as possible.

These types of batteries are definitely not meant to be kept at 100%. I'd rather go easier on the battery until I needed the last 20%. I guess it all comes down to how long you will keep the device. I wouldn't give a shit if I only kept it for 2-3 years.

For sure the device battery manager helps, just not enough for the long term at the moment. I probably wouldn't even write this up if Google did as Samsung and made it so the batteries had 2000 cycles!

Edit
Also matters if the battery is designed with a proper buffer. 0% not actually being 0% and the same for 100%.

DeletedUser396

router99 I feel its the wanting of an app for everything. My opinion the 80% cut off is a gimmick

LGgos

TBH as I only tend to keep a phone for a couple of years I view this in the same way as screen protectors. Making my own experience worse out of a hope that it might sell for a little bit more if/when I come to chuck it on eBay and can claim "pristine condition", "99% battery SOH" etc and the next owner can have a better experience than I did. So I just use it. I'd rather not be constantly treating my phone as if the battery was degraded to 80% SOH, just so that the next guy can get a good 99% out of it and maybe bid an extra tenner.

A better solution would be if adaptive charging could be implemented. It doesn't have to spy on your sleep habits like the Google one, you could just tie it in to the alarm. If alarm set, charge to 80% until X minutes before the alarm then charge to 100.

Quantum

LGgos I always have two GOS phones. When I "retire" a main phone to be used as a secondary device it's nice if the battery is still in a good condition. I don't really wanna go to a repair shop to swap batteries either.

Keeping a phone for longer might also makes sense if supporting newer pixels become harder.

LGgos

Quantum Fair point. My approach doesn't necessarily suit others!

Kind of concerned about future Pixels being locked down as well. I guess if the various authoritarian governments currently plaguing us all force locked bootloaders and encryption backdoors like they keep trying to, I might in any case go back to flip phones and pen pals.