The standard voltage of 18650 lithium batteries is typically 3.7V, which is their nominal voltage. During the charging process, the voltage of the battery gradually increases, and the maximum voltage when fully charged can reach 4.2V. It should be noted that the voltage of 18650 batteries of different chemical systems may vary slightly, but the maximum charging voltage of most lithium-ion batteries is controlled within 4.2V.
II. Voltage Considerations During Charging
Charger Selection: Only use the dedicated charger. Ordinary chargers may cause overcharging.
Voltage monitoring: If the voltage exceeds 4.2V during charging, the charging process should be immediately stopped.
Temperature impact: Charging in high-temperature conditions may cause abnormal voltage increase.
Difference between new and old: The aged battery may not be able to reach 4.2V.
III. Common Misunderstandings in Usage
Many users mistakenly believe that the higher the voltage, the better. In fact:
Exceeding 4.2V will accelerate the aging of the battery.
Long-term storage at high voltage will shorten the battery‘s lifespan.
The voltage characteristics of batteries from different brands may vary slightly.
The discharge cut-off voltage is usually between 2.5 and 3.0 volts. Excessive discharge is also harmful.
