Is it true that lithium-ion batteries are harmful to long charging?

Question

Batteries

I heard somewhere that smartphones after purchase need to be discharged to zero and charged for 9-12 hours, 3 times in a row. And, after that, as they promise, it will work a little longer.
In this regard, questions:
1. Is this a myth since the days of nickel-metal hydride batteries?
2. Does this contribute to more battery wear, or does it improve battery performance?
3. And is it harmful to recharge the phone until it is fully charged, when there is still enough charge?
Thank you.

Answer 1

1. Lithium batteries do not have a "memory effect", such as nickel-cadmium batteries - therefore, it makes no sense to discharge them to zero and then charge them.
2. Lithium batteries are destroyed during deep discharge (i.e. when you completely discharge it to zero). - therefore, it is absolutely impossible to allow a full discharge (it will not be covered immediately, but the capacity will fall as a result of destruction)
3. It is considered optimal (for storage) 40% of the charge - therefore it is necessary to charge it to the full when it is needed.
4. Batteries have a noticeable self-discharge. Moreover, the larger the capacity, the stronger the self-discharge (should be taken into account, in addition to paragraphs 2 and 3) - therefore, during storage, they should be recharged periodically. (for reference - my tablet, which, judging by the volume, has a battery of 3-4 ampere hours, lost 12% of the charge in a month of lying in the off state).

Answer 2

There is ALWAYS a charge controller in the smartphone-battery bundle. It can be built into the battery itself or into the phone. He makes sure that the discharge is not too deep, but at the expense of the upper limit - everything is on the conscience of the manufacturer. Consumers love bigger batteries.
There is no need to "rock" lithium-ions, just charge and go.

Answer 3

I'll add my 5 kopecks:
Lithium-ion does not require complete discharge, does not like to be fully charged. failure to comply with these 2 rules leads to a reduction in service life.
1) This is rather a misconception associated with a lack of information about the optimal operating modes.
2) "What doesn't kill us makes us stronger" - in this case it doesn't work! The resource will decrease.
3) Lithium-ion do not tolerate high temperatures (capacity decreases). Short recharging - including reduces the thermal load. But the other "end of the stick" is reloading