No, if the self-consumption of the protection board is high and the battery is not used for a long time, the battery voltage will be 0V. Generally, the self-consumption of the protection board of a cell phone battery is. about 6uA.
Voltage: Voltage, also known as potential difference or potential difference, is a physical quantity that measures the difference in energy produced by a unit charge in an electrostatic field due to different potential. This concept is similar to “water pressure” caused by high and low water levels. It should be clarified that the term "voltage" is generally only used in circuits, while "potential difference" and "potential difference" are generally used in all electrical phenomena. The SI unit of voltage is the volt (V). One volt is equal to 1 joule of work done for each coulomb ofload, i.e. 1 V = 1 J/C. The international unit of voltage is volt (V), and commonly used units include millivolt (mV), microvolt (μV), kilovolt (kV), etc.