Is it normal for my iPhone 13 to have a Battery heath of 98% within 3 months of use?

Your Battery Health is quite normal. Battery Health is an inexact figure that varies with usage. The normal Apple Battery will last for 2 years of normal use. When Battery Health reaches 80%, it will be time to make an appointment at the nearest Apple Store for Battery Replacement. Check this link...

Batteries - Maximizing Performance - Apple

Battery Health will decline on average at about 1% a month. But, that's an average. Some months it might not decline at all, then drop 2% the next month.

So, it would be normal to expect that the Battery Health was in the 97-98% range after 3 months.

Also, keep in mind that Apple rounds the percentage numbers down to the next whole number. So, the battery might be at 98.9%, but this will be displayed as 98%.

So, while it might look like the battery dropped from 99% to 98%.....a 1% drop......it is possible that the battery only dropped from 99.1% to 98.9%.....a drop of only .2%.

Personally, I do not buy in to the 80% charge limit theory, but that is another discussion.

+1 on frassm737's evaluation, and especially for pointing out "inexact."

This is the battery capacity, or "health," history of my iPhone SE 2020 from new in November 2021, as tracked by the Coconut Battery app:

Note:

• my battery started life at 102%. Go figure.
• the capacity reading is non-linear. Its trend is linear (normal) but spot values jump around.

This battery gives more than acceptable runtime today after nearly three years of daily use. I have a couple of devices whose battery are well under 80% and still give adequate runtime for the limited needs those devcies have to serve.

80% is a useful target value but not engraved in stone. Replacing at 80% is good future-proofing but I've found with my devices that as long as the battery does not show signs of catastrophic failure (bulging, runtimes plummeting to minutes, etc) you can keep using a battery as long as it meets your runtime needs.

The 80% number seems to have come from guidelines Apple techs used evaluate batteries for WARRANTY service. That guideline for years was that, if the battery in a device UNDER APPLE WARRANTY fell under 80% capacity (health) at less than 1000 cycles, Apple MAY elect to replace the battery at no cost to the owner.

Well, you asked Allan Jones about his charging habits, but did not respond to my post. Since you are asking about this........I set up the phone for Optimized Battery Charging. If there is an 80% limit option, I do not use this and instead let the phone charge to 100%.

I connect the phone to the power adapter at night and let it charge the phone all night.....every night.

When you do this, the battery charges up to 80% normally and then it rests and is very slowly trickle charged over the next 4-5 hours up to 100%. So, you start every day with the battery at 100%.

My opinion.....the 80% charge limit is a gimmick to respond to the popular notion on the Internet that the battery will be damaged if it is charged up to 100%. Even if you enable the 80% option, the battery is still charged up to 100% occasionally, which Apple tells you about in a footnote buried where it is hard to find.

I have used the 100% method for many years. I'll get almost 5 years of use on the battery in my current phone when most users only get 2-3 years.

Enable Optimized Battery Charging on your phone

Connect the power adapter to the phone at night and leave it connected all night.......every night

Not only is this the simplest way to help your battery, you start each day with the battery at 100%

Depends on how much you use it daily. My 2+ years 13 pro max still has over 91% of battery capacity. And I use it very highly every day.

Bob Timmons wrote:

Personally, I do not buy in to the 80% charge limit theory

Ditto.