iPhone 15 Pro battery capacity at 81% should I replace it?

iOS 26 is still in beta. Nothing anyone says about "battery issues" or anything else is even remotely relevant to how the final release will perform.

The rule of thumb for battery replacement is 80%.

Here's the choice:

If you plan to upgrade to whatever new model gets released this fall, I wouldn't waste the money on replacing the battery. If the carriers follow the pattern of the last few years, you can potentially trade your 15 in with them instead of Apple and get a new phone almost free...

If you plan to keep the 15 or hand it down to a family member, get the battery replaced soon.

As KiltedTim explained, updating to iOS 26 is not really the issue.

However, as your battery declines in health, the phone may be throttled to prevent unexpected shutdowns. This means that the phone will feel slower than it did when it was new. If this happens around the same time as you update the system software, it's easy to think that the update is the issue.

If you plan on keeping the phone, I'd advise you to make an appointment to have the battery replaced before you update. Not because iOS 26 is going to cause a problem but because the phone will be in its best working condition when you do update.

The battery on my iPhone 15 Pro (purchased on launch day) is at 86%. I'm waiting until Apple announces the next generation of phones to decide if I'm going to wait and get the battery replaced or if I'm going to go ahead and get a new phone. If my battery is above 80% and I decide to keep the phone, when iOS 26 is released, I will be updating.

The part given below is extracted from --> iPhone battery and performance - Apple Support (IN)

"Battery health degraded

If battery health has degraded significantly, the below message will also appear:

Your battery’s health is significantly degraded. An Apple Authorised Service Provider can replace the battery to restore full performance and capacity. More about service options…

This message doesn't indicate a safety issue. You can still use your battery. However, you may experience more noticeable battery and performance issues. To improve your experience with a new replacement battery, get a service.

"

You can ask them, but don't assume an Apple Store can do a battery service while you wait. There are so many variants of iPhones that few stores can inventory every battery type. They will likely send it to their centralized refurbishment center.

Remember, you alone are responsible for backing up your phone before handing it over for any service. You also must log out. See: What to do before you sell, give away, or trade in your iPhone or iPad - Apple Support

Please avoid non-Apple solutions if possible. Oh, the sad stories we see here!!

When I needed Apple's battery service, I started here: iPhone Battery Replacement - Apple Support

I used the "Send in" option and the service, counting transportation took four working days. Couldn't be happier. Dropping it for service at an Apple store can add a day at each end.

Your options may be limited by your location. I'm in the US.