Is 98% battery health after 105 cycles normal for iPhone 17?

amirbeyl wrote:

My iphone 17 normal after 105 cycle battery health 98% its normal?

Yes, it's normal. On average, for every 50 cycles, you can expect about a 1% loss in battery health. 105/50 = 2.1. Which means your battery health is normal after 105 cycle charges.

Perfectly normal.

On average, over time, expect the battery to decline about 1% for every 50 Charge Cycles. But, the decline is not linear. Some months, the battery might not decline at all, then go down 2% the following month.

After 500 cycles, the battery will be about 90% and about 80% at 1,000 cycles, when the battery will need to be replaced.

amirbeyl wrote:

Why all my friend iphones in 150 cycles still 100% ??

My iPhone 17 Pro Max dipped to 99% after only 47 cycles. No two phones are used in the exact same manner and no two batteries will decline in the exact same way either. Some batteries have a higher capacity than what they were originally rated for. If a battery comes with more than the mAh rating for the battery it may take longer to show decline, but those batteries will decline and they will likely decline pretty rapidly when they do.

If you are looking for anyone to tell you what you're seeing is not normal, you won't get that here. There is nothing wrong with your phone. The battery is performing within specification for your phone. Worrying about the natural decline in battery health, which can't be stopped is pointless. Stop worrying about it. Enjoy your phone. And when the battery dips to 80% which is a long way off, then it's time to pay Apple to replace the battery and the battery decline clock starts all over.

amirbeyl wrote:

Why all my friend iphones in 150 cycles still 100% ??

Their's will average out just like yours did. The battery is expected to last 1000 charge cycles before the battery needs replacing when it falls below 80%. The drop anyone experiences is not linear meaning it is not strictly tied to the Charge Cycles and the averages level out over time. Check again with your friends when you are all at 500 charges cycles and you may even find that theirs is less than yours, but the expectation is that they will be somewhere around 90%, give or take a couple of points on either side at that point.

Due to the vagaries of mass production, your battery's initial capacity will not be the same as your friends' batteries. All mass-produced items must have allowable ranges for their metrics. It is the "±" seen on engineering and process documentation.

Health is a calculation that is based on the AVERAGE initial capacity of batteries of that model. It is not based on YOUR battery's actual initial capacity. Therefore health is inexact

The rate of change of health over the battery's lifespan is uneven. The change seems to slow after 90%. The battery in my iPhone SE2 has been aroung 80-82% health for months. Therefore health is non-linear.

Please do not waste worries on an inexact and non-linear metric.

Oh, yes. Remember this about "averages":

Are you and your friend running exactly the same apps all the time and spending exactly the same amount of time on your phones every day?

Of course not. Some users will get better than normal results and some will get worse than normal results. It all depends on which apps are running and how much you are using the phone on average each day.

Don't try to babysit your battery. It will not help, and it will just make you nervous when there is no reason to be. The battery is going to do what it is going to do.