iPhone 11 Two battery related questions

[eclipse01]

So i have 2 Iphone 11's in my family, both purchased the same time.

Iphone #1 shows battery health (max capacity) at 75 and is typically charged only at nights
Iphone #2 shows battery health at 84 and is charged here and there throughout the day and maybe at night.

What would make Iphone #1 so much lower, this one seems to be used a bit more "gently" when it comes to battery life and charging? Is there a science to this or recommended uses to keep the max health up?

Question #2

I have an Iphone 12 with Apple care ending soon, if i plan to keep my phone maybe another year or 2. Should I do the "free" battery swap on my device before it ends? Is this common practice with people with apple care? (especially when it is ending?)

 

[Shadowbech]

So i have 2 Iphone 11's in my family, both purchased the same time.

Iphone #1 shows battery health (max capacity) at 75 and is typically charged only at nights
Iphone #2 shows battery health at 84 and is charged here and there throughout the day and maybe at night.

What would make Iphone #1 so much lower, this one seems to be used a bit more "gently" when it comes to battery life and charging? Is there a science to this or recommended uses to keep the max health up?

Question #2

I have an Iphone 12 with Apple care ending soon, if i plan to keep my phone maybe another year or 2. Should I do the "free" battery swap on my device before it ends? Is this common practice with people with apple care? (especially when it is ending?)

1. Hard to say. Just because both were purchased at the same time doesnt mean both should have equal amount capacity as each battery may behave differently.

2. Apple will only replace battery under warranty or even through apple care if the the battery health reaches below 80%. So if its 79% and still have coverage, they will replace it.

 

[MacCheetah3]

Is there a science to this or recommended uses to keep the max health up?

Batteries - Maximizing Performance

Maximize the life and lifespan of the rechargeable lithium-ion batteries in your MacBook, iPod, iPhone, and iPad.

www.apple.com

The General Performance Tips are most relevant to your questions/concerns. The device specific tips are meant to extend/maximize operating time per charge.