Battery display percentage changes when turning off then on

[flaxseedoil1000]

In this instance it showed 70%.
Turning it off then immediately back and and it changed to 78%.
I have seen it change 12% at times.
Thoughts?
tia

 

[fooferdoggie]

it is the higher voltage batteries charging the lower voltage batteries.

 

[flaxseedoil1000]

Thank you for the clarification.