Warns when battery power is below 20% while unplugged, and above 70% while plugged. Charging between these percentages increases the battery's longevity.
Source 1: https://batteryuniversity.com/index.php/learn/article/how_to_prolong_lithium_based_batteries
Source 2: https://pushevs.com/2018/04/27/battery-charging-full-versus-partial/
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