[shawnz]

It's very bad for the lifetime of a lithium battery to let it drop all the way to 0% charge

[dwighttk]

Do most devices wait until 0% to turn off?

[shawnz]

No, but the higher the depth of discharge, the worse the degradation will be.

See: https://batteryuniversity.com/index.php/learn/article/how_to...

[BlueTemplar]

The "0%" is somewhat arbitrary, this is also why it's recommended to keep lithium ion batteries between 25% and 75%.