So I have a couple month old OnePlus N30 phone, and one thing that drives me crazy with it is when I plug it in at night to charge, eventually it fully charges. You would think this is good, but then it decides to vibrate every 30 seconds or minute or so to tell me it’s fully charged. Over and over again till it wakes me up and I unplug it. So far it’s still mostly charged by the next morning but this is ridiculous - aren’t you supposed to charge the phone overnight?
I tried just turning off the notification but the phone is using the system UI to notify and won’t let me turn it off.
Does anyone know how to stop this?
None of this is true anymore, kinda. Modern phones now bypass the battery so your charger is actually powering your phone directly. As for the 80% thing, you’re correct, except that manufacturers account for that and calibrate such that what you think are 0 and 100% are actually closer to 20 and 80% respectively. And that’s not just for phones. Steam Deck, Nintendo Switch, tablets, laptops, etc. Manufacturers learned to not trust their end users to be technically knowledgeable about this sort of thing since nobody reads the manual and the consequence could be fires or explosions, and that’s gonna hit the news without nuanced details, and that’s then gonna tank their company’s stock value. They found that it was just much more stable and profitable to include some basic lines of code to feed you comfortable little lies that keep you safe :)
It’s actually the other way around. A safe cutoff voltage to prevent battery degradation is about 4.2V, but most modern phones charge until 4.45V, so they can advertise a bigger battery capacity at the cost of long term battery health. Your phone essentially charges itself to more than 100%
Yes, the battery doesn’t charge to “dangerous - could explode” levels. But they very much do still charge to levels that are damaging to long term health/capacity of the battery.
Yes, they tune the batteries so that 100% isn’t the absolute cap. But even with that accounted for, many batteries will be above values that would be considered good for the long term health of a lithium cell. 80 percent on most phones is still very much at levels that are considered damaging to lithium batteries.
To put it another way, the higher you charge a lithium battery, the more stress you put on it. The more stress you put on it, the fewer charge cycles those components will hold. It’s not like there’s a “magic number” at 80 percent, it’s just that the higher you go the worse it is. Yes, some manufacturers have tweaked charge curves to be more reasonable. But they’ve also increased limits. Many batteries now charge substantially higher than most people would consider sustainable.
And after such changes, 80% lands pretty close to the general recommendations for improved battery longevity. Every percent will help, but it’s not a hard and fast rule.
Calibrations have gotten a little better in some ways, but all you have to do is look at basic recommendations from battery experts and look at your phones battery voltage to see that almost every manufacturer is pushing well past the typical recommendations at 90 or even 85 percent.