iPhone 13 Pro Max battery health

Batteries are consumables; they lose a little capacity every time they are discharged, then recharged. On average this works out to about a 1% loss for every 25 “full charge cycles”. As one example, if you charge the phone overnight, every night (and that is what you should do; it is a best practice), it starts the day at 100%. If it drops to 20% by the end of the day before you charge it again overnight that counts as 0.8 full charge cycles (20% to 100%), or about 24 full charge cycles per month of use. For this example your battery capacity will lose about 1% per month. Of course, if the end-of-day level is higher than 20% the capacity loss will be a little less, and if it is lower than 20%, or you charge it during the day, the capacity loss will be higher.

Once the capacity drops below 80%, or if there is a message in Battery Health that the battery is not meeting peak performance expectations, it’s time to change the battery→iPhone Battery Replacement - Official Apple Support

The absolute best way to get maximum use on a charge, as well as slow the decline of battery capacity long term is to enable Optimized Battery Charging (Settings/Battery/Battery Health) and charge the device overnight, every night. The battery will fast charge to 80%, then pause. During the nighttime pause the phone will use mains power instead of battery power, allowing the battery to “rest”, and thus reducing the need to charge the battery quite as often. The phone will resume charging to reach 100% when you are ready to use your phone; it will “learn” your usage pattern. If you enable iCloud Backup (Settings/[your name]/iCloud - iCloud Backup) the phone will back up overnight also, assuring that you can never lose more than the current day’s updates. Here's more information→About Optimized Battery Charging on your iPhone - Apple Support

A

How old is the iPhone? It is normal for the Battery Health to decline an average of about 1% a month. That's an average. Some months it might not decline at all, then decline 2% the next month.

The battery is working overtime after any major iOS update. Things will calm down after a day or two.

You should plug your phone into the charger and let it charge overnight every night.

#1. You are not our customer… We are not Apple. This is a user forum. You are not talking to Apple.

Battery health will naturally decline with use and age. That’s the nature of Lithium-ion batteries. It’s physics… that’s how it works.

On average, you will lose approximately 1% of battery health per month. Sometimes more, sometimes less.

Don’t stress over it.

I bought it in january

That is 8+ months ago. Your Battery Health should be at about 91-93%. If your Battery Health is 99% as you say......or even if it is 96-98%, you should send flowers to Apple.

You have an exceptional battery in your phone. Be thankful.

For about the firs 24-48 hours after an update, the phone is doing a bunch of background, housekeeping tasks. And, you're probably playing with the new features. Both will cause your battery to drain more quickly than usual.

There is nothing wrong with your battery.

No. You don’t have a 14 Pro Max. The 14 Pro Max hasn’t been released yet.

Battery Health will naturally go down with time and use. There is nothing wrong with the phone you have.

Approximately how old is the phone?

There is nothing wrong with your battery.