Mobile phone can only be charged to 90, recommended:
1. Reinstall the battery (possibly due to poor contact).
2. Replace the power socket.
3. Check whether the original charger is used. If not, please replace the original charger to try.
4. Replace another battery
5. Check whether you have recently downloaded third-party battery software, and uninstall it.
If it really goes straight to 97 percent, then you can go to the Apple experience store, where you can solve it. Sincerely answer for you, give a good review, thank you