I use battery widget reborn. But basically any app the puts the percentage in the notification bar would show on the second screen. Unless there are too many notifications as was stated earlier.
Oh..I like it has green color. Gonna check it out. ThanksI use Battery Notifier Pro BT from the Play Store. It shows the battery percentage when the screen is on or off. I use the green colored font so i can see it.
https://forums.androidcentral.com/e...=com.larryvgs.batterypro&hl=en&token=oyiqIsPm
Been using it for years now.
I just installed the free version of Battery Notifier and I now have a nice blue percentage on the second screen!!!! Yaaaay!!! I might end up buying the pro version so I can have neon pink!!