Hi,
Different things can affect battery life such as the phone searching out signal strengths so if signal perhaps drops it'll work harder to remain connected.
Closing down apps and usage patterns all go to affect battery.
Perhaps a new app downloaded is affecting battery performance.
It can help to calibrate the battery by letting it drain to approx 5% and then fully charge to 100%
If you are still experiencing lesser battery performance then you can speak to Samsung UK Support to arrange a diagnostic run on the phone and battery.
http://www.samsung.com/uk/support/category/mobile/mobiledeviceHere are some tips from a Google Search and I hope it's ok to post some to try and help you.
It is recommended to keep a black background and black theme for appa, as each background light, lights up individually on the Super AMOLED screen of the Galaxy S6.
Go to Wi-Fi>> More>> Uncheck always searching for Wi-Fi.
Disable Smart Lock when not in use from Settings>> Search>> Trust Agents.
Keep updating Samsung Push Services from App Store.
Disable movements and gestures feature, which can be found under Settings>> Movements and gestures.
Note that Gmail app uses less battery than the stock Email app.
Turn off the features such as Sync, NFC, GPS when not in use.
In low network coverage area, use HSPA connection instead of 4G, although it does not seem to have much difference in terms of speed, the phone uses less power.
Turn on the Grayscale by tapping thrice on the home button for your screen for less power consumption. Go to Settings>> Availability>> Direct access>> turn Grey scale on.
The Facebook and Messenger app also use a lot of battery. Apart from these, you might disable the following apps when you are not using them to save power.
Drive, Google Book, Play and Now, Hangout
Instagram, Onedrive, S Health, S Voice
Skype and WhatsApp
The Battery Saver mode improves battery life. Just set Battery Saver to a certain level so that when your battery reaches to that particular level, the feature will turn on.
Turn off the Greenify apps that run in the background such as Dropbox, 9gag, MyFitnessPal and Wordfeud.
Set the screen brightness to low instead of using auto-brightness.
Switch off vibration alerts for Feedback, keyboard and ringing.
Turn off the Google location history.
It is nice to have widgets, like weather, on the new Galaxy smartphone but they eat quite a lot of power too.
Current Phone >
Samsung Galaxy s²⁵ Ultra 512gb.
