Is the battery of my phone in warranty

Hi zuhalb225,

Welcome to the Community of Apple users, where some of us do our best to help each other.

(If you want to contact Apple directly, there is a "Get Support" link at top right of this page.)

Here is where to check if your phone is in warranty

Check your Service + Support Coverage

https://checkcoverage.apple.com

I may be wrong, but I understand the Battery would be considered ok by Apple at 95%

There is a lengthy article discussing battery use :

When to charge your iPhone or iPad

https://discussions.apple.com/docs/DOC-9732

There are Battery support Articles from Apple Support online:

Get help with your Mac Battery:

hthttps://www.apple.com/batteries/service-and-recycling/

Batteries: Maximising performance:

https://www.apple.com/batteries/maximizing-performance/

Battery Service:

https://www.apple.com/batteries/service-and-recycling/

Hope this helps you :)