Hello:
——★1. Answering your question precisely is indeed very difficult: the brands and quality of batteries are different. There are differences, and their self-discharge sizes are also different. Also, the same battery has newness, storage environment, production date, etc. different, which also have a great impact.
——★2. Under normal circumstances, if the lithium-ion battery is fully charged and left for 60 days (two months), and the voltage remains above 75% of the rated value, the battery is good. The self-discharge characteristics of lithium-ion batteries are not linear, which requires special attention. When the rechargeable battery is stored, it should be recharged once a month. It is best to deeply discharge it once every six months and then store it fully charged, soto maintain battery activity as much as possible.
Hello:
You are very professional in electronics. My answer to your question is:
1. phone lithium battery The rated voltage is 3.7V, the cut-off voltage is 3V (lower than this voltage means over-discharge), and the voltage when fully charged is 4.2V Chargers on the market basically use the voltage comparison you mentioned. to check whether to stop charging. The set voltage is 4.2V, that is, charging stops when the battery voltage reaches 4.2V, indicating that the battery is fully charged.
2. To charge the cell phone battery, the charger can choose an output voltage of 4.2 ~ 5 V. During the whole charging process, the voltage changes like this. At first the voltage will rise sharply from just over 3 volts to 3.7 V.It won't take long to go from 3.7V to 4V. Finally, 4~4.2V will charge very slowly. In professional terms, battery charge is also one of the most critical battery performance indicators.
To do a voltage comparison yourself, simply set it to 4.2V.