Press down on the low battery notification when it pops up in the tray. It should show up with low battery alerts. Go to all categories & this should take you to the system ui where you can change the settings. Go to low battery alerts & go to importance. Set this to low - no sound or visual interruption. This should work. It took me a while to find this so I hope it helps 😎
PS: You can also add the system ui to your phone by going to the notification tray & holding down on the settings cog. It will add a quick ui that you can find under the system heading in settings 🐕
