My Uncle gave me his old Android phone (Galaxy J3 2018). The charge port built in is damaged so it's almost impossible to keep a cord plugged in to charge it up. That means when this goes, it might never get charged up again. Later on I might try to get it fixed.
But for now I was just tapping around on it and found out a way to extend the current battery life.
Swipe up from the bottom and tap on the Settings icon (if not visible already on your screen).
In the Settings scroll down and look for the option Device care.
In the next screen with the Optimize now option scroll down until you see the Battery icon on the bottom left. Right now I have 1 day and 5 hours battery life available. tap on the Battery icon.
Under the Power mode in blue letters tap on what ever is there. It might say Optimized or in my case Medium power saving. Tap on the blue letters.
On the next screen, I'm going to select the Maximum power saving option.
The screen shows you what is going to be restricted. Just tap on Apply.
Wait a few minutes for it to get ready and it goes back to the home screen. All black screen no background picture, minimum icons. Before this I had 1 day 5 hours of juice left but now I have now 3 days and 19 hours remaining on my battery charge.
Here's a simple chart based on the power options currently on my phone. Your milage may vary, depending on your phone, the plan you pick and how much you use your phone.
Is there a downside?
No background pic.
Only four icons may be added along with the default four. Just tap on a plus sign and choose your app.
If you go to the Settings options, you'll notice your settings options are limited. You would need to disable this to get to the full list of available settings options.
After initial setup, you can easily turn off/on by swiping down from the top (right to the bottom for the full menu) and tapping on the Power mode button. When I first clicked on this button I was only given the option to set it to Medium. I had to go to Device care as instructed for the other options. But now I got Maximum set I can use that option to switch plans.
I don't know how this will affect the speed of your phone. especially if you are playing games. If you have ever changed any of these options, let us know your experience in the comments.