why my battery drop too fast

Hello Yaya_0302,

1. Open Settings
2. Scroll down and tap on Battery

This is where all information about the battery is stored. You can see what has contributed the most to battery drain over the Last 24 Hours or over the Last 10 Days. If you look at the Battery Level graph, click the the battery is draining the most, or significantly. When you tap on the graph, it's going to filter by that timeframe and show you what apps were used during this time. You can experiment with this and figure out what apps is contributing the most to battery drainage. You can remove the app, stop background app refreshes, if it's a game lower the quality, or just use the app a little less! You can use Screen Time to setup restrictions if you believe you're using an app too much or an unhealthy amount.

You can also tap on Battery Health & Charing (within the Battery settings), make sure Optimized Battery Charging is enabled. Another thing to keep an eye on is your battery health, or Maximum Capacity. I've seen other people on this forum say that Apple recommends getting a new battery or device when this drops below 80%.

If you wish to learn more about batteries:

1. Batteries - Apple
2. Batteries - Maximizing Performance - Apple

I hope this helps!