[HARDWARE]■ STORY TIMELINE
WHY YOUR PHONE DRAINS BATTERY WHEN POWERED OFF
Even when turned off, smartphones continue to lose charge due to internal chemical processes and circuit board drain. This self-discharge is a fundamental characteristic of lithium-ion batteries.
Engadget+0m
If you need to juice up your phone in a hurry, there are more effective tactics than turning on airplane mode.
Engadget+1d
Your battery is continually losing charge.