1. Battery capacity
The capacity of a battery is determined by the amount of active material in the battery, usually expressed in mAh or Ah. For example, 1000 mAh means that it can be discharged at a current of 1A for 1h, which translates into a charge of about 3600C.
2. Nominal voltage
The potential difference between the positive and negative electrodes of the battery is called the nominal voltage of the battery. The nominal voltage is determined by the electrode potential of the electrode plate material and the concentration of the internal electrolyte.
Lithium discharge graph, is parabolic, 4.3V down to 3.7V and 3.7V down to 3V, are changing rapidly. But about 3.7V discharge time is the longest, accounting for almost 3/4 of the time, so the nominal voltage of lithium batteries is to maintain the longest discharge time of that voltage.
The nominal voltage of Li-ion battery is 3.7V and 3.87V, if it is 3.7V, the charging termination voltage is 4.2V, if it is 3.8V, the charging termination voltage is 4.35V.
3. Charging termination voltage
When the rechargeable battery is fully charged, the active material on the pole plate has reached saturation, and then continue charging, the battery voltage will not rise, the voltage at this time is called the end of charge voltage. Lithium-ion batteries are 4.2V or 4.35V.