iPhone 6s Battery Life Drain and Overheating After Updating To iOS 13

Hello SamiaF,

Welcome to Apple Support Communities. I understand since updating to iOS 13 and subsequent updates, you’ve experienced poor battery life and phone being hot to the touch. You have reset all settings, reset network settings, restored from and restored from iTunes backup, use low power mode, fetch mail rather than push, turn off background app refresh, and update all apps. I know how important it is to have your iPhone working as expected, so that you don’t miss any important calls or messages. I’m happy to help.

Please use the steps here to keep your iPhone within acceptable operating temperatures: Keeping iPhone, iPad, and iPod touch within acceptable operating temperatures - Apple Support

Please go to Settings > Battery > Battery Health > Maximum Capacity. What percentage is shown there? Does it show that your iPhone battery is supporting normal peak performance? Here’s more information on battery performance: iPhone Battery and Performance - Apple Support

Prior to restoring your iTunes backup, were you able to test your iPhone set up as new to see if the issues persist?

Take care.

Welcome back SamaiF.

I appreciate all of the steps that you have done in troubleshooting. Since you’re still experiencing the same issues after restarting to factory settings and setting up as new, I recommend contacting Apple Support here: Get Support

Take care.