If the voltage of a lithium-ion cell drops below a certain level, it's ruined. Lithium-ion batteries age. [Source]
As an owner of quite a lot of expensive mobile devices (lots of Apple stuff for example) I wonder... what if I, say, put my Airpods in a drawer at, say, 3% charge and "forget about them" for a few months?
Li-ion: 5% in 24h, then 1–2% per month (plus 3% for safety circuit) [Source]
Will my device be unusable? As I understand it I won't be able to charge it anymore?
Also: How does Apple (or any other manufacturer) make sure that devices in warehouses etc. don't "die out" during the time they're in there? I know that Apple devices usually come out of the box at least partially charged, but I assume Apple doesn't charge the devices to 100% anyway. But what if the charge drops below "0%" (or: the 'certain level' from above quote)?
Also: what is "ruined"? The above quote implies the cell being unusable, beyond repair, FUBAR. However:
The protection circuit turns off and most chargers will not charge the battery in that state. A “boost” program applying a gentle charge current to wake up the protection circuit often restores the battery to full capacity. [Source]
Some battery chargers and analyzers (including Cadex), feature a wake-up feature or “boost” to reactivate and recharge batteries that have fallen asleep [Source]
Would such a 'wake-up' be available in consumer products (laptops, phones, earbuds, whatever) or would this be put only in industrial stuff?
Lithium-ion batteries age. They only last two to three years, even if they are sitting on a shelf unused. So do not "avoid using" the battery with the thought that the battery pack will last five years. It won't. [Source]
Is that information outdated? I have had quite a few mobile devices over the past decade(s) that lasted much longer than that.
I'm trying to make sense of a lot of sources that all seem to contradict each other one way or another.