Why does my battery drain significantly faster when under 10%?

[benakaget]

And it's not just my S24, its every Samsung I've owned. They drain at a consistent rate, then once they get to 10%, it's being drained 1% every 20 seconds. 

[arianwen27 · Accepted solution]

Lithium batteries are on a curve for how well they hold power. Past a certain point, they die super fast. Your phone will try and adjust the numbers to avoid shooting down at 10% but the older a phone gets, the faster it goes. It's just how modern battery tech works.

Iphones actually lie a bit in how their battery works. They make higher percentages drain faster so lower percentages can look like they drain slower. So overall it looks consistent. There's a whole art in making a battery parcent accurate vs something users can understand

[benakaget]

So say the phone lasts 24 hours on standby.

It would stay between 100% – 90% for about 5.5 hours.

89% – 11% for about 18 hours

10% – 0 for about 30 minutes??

Using rough numbers but...yeah??

[arianwen27]

It depends a lot on how the phone software is setup and age of the battery so I can't give flat numbers. If samsung members diagnostics says your battery is OK, it should be normal yeah. I've seen an s22 from 10% drop 1 per minute, older device, older battery

[JAMES4578]

For optimum Battery life in modern Devices it is best not to let Battery Drain that low, Samsung suggests your phone runs between 20 and 80%. obviously this may not always be possible and to an extent depends how often you upgrade.
whilst I fuly charge do not let it go below 15% anyway and try to charge at 20%. once at 10% it does drain pretty quickly particularly if older device, some Battery tips in this article https://electrontogo.com/blog/myths-about-cell-phone-battery-life-vs-truths-behind-them