SamsungGalaxy Note 9 comes with a 4000 mAh battery and provides various ways to increase battery life but you may feel as though battery life seems to be a bit short during the initial period after the purchase.
This may happen because the App power monitor feature and Optimization of battery usage feature is not working properly as yet as it has no battery usage data to use.
Depending on your battery usage pattern, if you optimize the battery usage time by activating App power monitor feature and Optimization of battery usage feature, you may see an improvement of the battery life of the device from about 7 days after the opening of the device. Though, the usage time may vary depending on your device settings, usage pattern and operating conditions.
Please follow the steps below:
1. Optimize Device:
Go to Settings > tap on Device Maintenance > OPTIMISE NOW.
The quick optimization feature improves device performance by Clearing cache memory, Deleting unnecessary files, closing apps running in the background, Managing abnormal battery usage, Scanning for crashed apps and malware.
2. Prevent Background Apps:
Go to Settings > tap on Device Maintenance > Battery > select apps > SAVE POWER.
This will save battery power by preventing apps that are running in the background from using battery power when they are not being used.
Go to Settings > tap on Device Maintenance > Battery > BATTERY USAGE.
From here you can monitor which apps are draining your battery the most. Some apps can be draining your device even though they were not being used to use Battery Usage to check whether you want to keep that app or not.
4. Turn Off Auto Sync:
Go to Settings > tap on Clouds and accounts > Accounts > disable - Auto-sync data.
This will stop applications and account from syncing in the background which will save you battery life. However, this will stop notifications from coming through from these apps as they are not getting data from the server. You will have to manually check each application, and that's when it will start pulling data.
The Galaxy Note 9 comes with two customizable power saving modes to save the maximum amount battery life, first is 'MID' and second is 'MAX'.
1. MID Power Saving Mode
Go to Settings > tap on Device Maintenance > Battery > MID >Apply.
This will let you customize the including - Background network usage, Always On Display, Speed limiter, Decrease brightness, Screen resolution.
2. MAX Power Saving Mode
Go to Settings app > tap on Device Maintenance > Battery > MAX > Apply.
Maximum Power Saving Mode turns off everything except for a set of selected applications (default is Phone, Messages, Chrome, Settings). This will also let you customize the Background network usage, Always On Display, Speed limiter, Decrease brightness, Screen resolution.
Long screen time-out settings or high display brightness can substantially reduce battery time.
To change the Screen Time-out, Go to the Settings > Display > Screen Timeout > Select the desired option.
To change Display brightness, Swipe down the Quick Panel > Drag the slider to the left or right to adjust the screen's brightness. Or Go to the Settings > Display > Adjust the slider to change the screen brightness and make sure to disable 'Auto Brightness' option.
The Galaxy Note 9 support maximum WQHD+ display resolution, which is kind of a good thing to enjoy games and high-quality videos but on the other side it also uses an increased amount of power than the usual. That's why the Note 9 comes default at FHD+ resolution. You can tweak the resolution via the following steps.
Go to the Settings menu > Display > Tap on Screen resolution > Select a resolution by sliding the circle. Tap on Apply once you have selected your preferred screen resolution. From Here you can switch between HD+ (1480x720) / FHD+ (2220x1080) / WQHD+ (2960x1440).