Most battery issues can be fixed by doing a few simple things to make your battery work better. Check out this guide from Revibe. Here are some steps to make your battery last longer. 

Even if we give you a new battery, you might still have the same problem if you don't follow these steps:

1. Shut down power-hungry apps first. Go to Settings, tap Battery, and see which apps are draining your battery. If you find the troublemaker, update or remove it. You can always get these apps again later if they're not causing the battery issue.
2. Charge your device the right way. Don’t charge it in extreme temperatures or when it's in its case as it can make the battery less powerful.
3. Turn on 'Low Power Mode' to make your iPhone battery last longer. Go to settings, tap Battery, and switch on 'Low Power Mode.
4. Turn off 'Raise to Wake' by going to Settings, Display & Brightness, and switching it off.
5. Update your apps and iOS for better battery life. Open the App Store and hit 'Updates' to update all apps.
6. Turn off 'Background App Refresh' in Settings > General > Background App Refresh.
7. Stop 'Location Services' in Settings > Privacy > Location Services.
8. Turn off vibration in Settings > Sounds.
9. Turn off WiFi when you're not using it in Settings > WiFi.
10. Keep your apps updated to save battery. Open the App Store and update any apps in the Pending Updates section.

Consumable parts like batteries will naturally wear out over time and usage. We won't cover issues with these unless there's a manufacturing defect.