Problem: Troubleshooting methods to fix Samsung Galaxy S6 battery issues such as fast battery drain, phone charging or charging very slow, etc.
Method 1: Uninstall / Remove any battery saving related app installed on Samsung Galaxy S6.
Method 2: Boot Samsung Galaxy S6 into Safe Mode
Step 1. Press and Hold Volume Down Button and Power Button still you see the Samsung Logo.
Step 2. Release the Power Button while still holding on to Volume Down Button.
Step 3. Keep holding it until Samsung Galaxy S6 boots up.
Step 4. You should see Safe Mode written at the bottom left corner on the screen.
Method 3: Turn off app’s background sync or set them to only sync periodically.
Step 1: Go to Settings > Data usage.
Step 2: Open the context menu by tapping the three dots in the upper right corner of the screen.
Step 3: Uncheck Auto sync data.
Step 4: Ok.
Method 4: Switch off Bluetooth, WiFi and Data Connection when not using it.
Method 5: Turn on Power Saving Mode.
Step 1: From Home screen, tap Apps > Settings > Battery.
Step 2: From the Power saving mode section, tap MID for Power Saving Mode or MAX for Ultra Power Saving Mode.
Step 3: Tap APPLY.
Method 6: Factory reset.
Step 1: Open Settings > Backup and reset > Factory Data Reset.
Step 2: The on-screen prompts will warn you that all data will be lost and your phone will return to its default settings. Confirm that you wish to perform the reset, and then press Reset Device.
Step 3: Tap Delete All to proceed. Your phone will now be restored to its factory settings.
Method 7: Factory Reset via Recovery Mode
Step 1: Turn off Samsung Galaxy S6.
Step 2: Hold the Volume Up button, Home button and Power buttons down simultaneously until the screen shows iconic Android logo.
Step 3: You’ll have access to boot menu. Using the Volume buttons to navigate and the Power button for selection, find and select Wipe Data/Factory Reset.
Step 4: Scroll down to Yes, delete all user data, and press Power button once again. You will then notice script scrolling across the bottom of the screen, which will end with Data Wipe Complete.
Step 5: Press the power button to reset.
Method 8: If Samsung Galaxy S6 isn’t charging even after using several chargers, then replace the charging.
Method 9: If Samsung Galaxy S6 is charging slowly, please make sure chargers output not less than 5V – 2A or 5V -3A.
Method 10: Turn on airplane mode while charging helps it charge even faster.
Method 11: Battery replacement.