iPhone 5s
Want to give my iPhone 5s to my niece. It will not charge.
iPhone 4s, iOS 9
Question marked as
iPhone 5s is > 10 years old, which also affects the battery life. The hardware remains old, so does the battery.
If it is still possible, have the battery replaced.
The battery can be replaced by Apple or an Apple Authorized Service Provider.
See this Apple article: iPhone Battery Repair & Replacement - Apple Support
If you are going to replace the battery, see -> Get your iPhone, iPad, or iPod touch ready for service
Get your iPhone, iPad, or iPod touch ready for service - Apple Support
The price is approx $ 79.
If you want to know exactly, call Apple directly, see Contact Apple for support and service -> Contact Apple for support and service – Apple Support (UK)
or
call 1-800-MY-APPLE
note:
You have to decide for yourself whether it is still worth having the battery replaced.
Considering a newer type of iPhone?
Read this before you buy a newer type iPhone.