Hey people. I searched but i couldn't find a specific thread with the information that the title's talking about. So i will share this information here, to help some people that they maybe need this feature. Feel free to ask anything.As we all know OxygenOS doesn't have by default in the battery settings the feature to present the battery percentage inside the battery's icon, but only the way to choose your battery icon style or just the battery percentage itself.So this can be happen with an Android feature from the near past. It's simple and you don't need any 3rd party application. Just the OxygenOS stock as it is. I am currently in the full stock version OxygenOS 3.2.7 on my OnePlus 3 Soft Gold. OnePlus One (With OxygenOS installed) and OnePlus 2 users can try this and report back their result. It should work guys.We continue with the steps:1. Pull/Scroll down full the tiles/notification bar, untill you will see the little "gear" icon at the top right corner next to your battery icon that jumps to the Settings screen:2. Tap and hold the "gear" icon untill you will notice it moves like rolling for a bit. When you ll notice this, release your finger and then you should jump to the Settings screen with the appearance of a message for 1-2 seconds like "You have enabled System UI Tuner etc."If this ll not happen, try again cause it needs sometimes more tries to completely make it right.Then you should be able to see the extra option System UI Tuner in the Settings screen at the end of the bottom:3. Tap on this option and you will see the next screen bellow:4. As i did in the screenshot, enable the 1st option "Show embedded battery percentage"5. The end. You are ready.Extra photo of the battery percent inside the circle icon for a better proof:Voila.For those who wondering. The demo mode option is just for the effect we can say. What i mean.For example when unboxing an Android device without a sim card in use, if you ll enable it, you ll see your battery, wifi and sim card's signal icons full enhanced, but this is fake, just for the show as i said.