I find that my tablet battery is poor too. Reading this thread has made me feel so much better about my tablet. Standard rom no modifications. Lte version 8.4.
I get no more than 2 hours screen time and about 18 hours until I need to charge the battery again.
Some interesting observations, playing hay day absolutely kills my battery, I was watching 1440p videos and reading xda for ages from 20% battery life. Then I opened hay day for 1 minute and the message appeared that my battery was low. 30 seconds later the next message appeared to say my battery went from low to critical and the screen dims and if I don't plug my tablet in within a minute the battery dies and tablet turns off. Mega annoying.
I only ever charge my battery when it is less than 10% and leave it until it's fully charged.
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