18650 lithium battery parameters: Type is sealed cylindrical, rechargeable lithium-ion battery, model ICR18650, nominal voltage is 3.6V, weight is about 45g, CamAh is 2000mAh, charging voltage is 4.200±0.049 V, the minimum discharge termination voltage is 2.75V, the maximum charge termination voltage is 4.23V, and the maximum continuous charging current is 1500mA.
The capacity of 18650 lithium battery is related to voltage, current, temperature and other parameters. The discharge voltage range of 18650 lithium battery is 3.6~4.2V, and the discharge capacity range is 10~100mAh/g.
The discharge characteristics of 18650 lithium battery include constant current discharge and constant voltage discharge. When the current is small, the charging voltage is high, so the discharge characteristics are fast first and then slow. The electrolyte inside the lithium-ion battery has different reaction systems. When the electrolyte concentration in the electrolyte is constant, the greater the internal pressure of the solution, the smaller the current. Therefore, the lithium-ion battery will produce a larger amount of electricity (actual capacity) when charging. Generally, the performance of batteries with higher charging voltage and larger charging capacity will also be improved.
Differences in lithium battery types:
The lithium battery label is the same as 3.7V or 4.2V. It's just that the manufacturer's labeling is different. 3.7V refers to the platform voltage (i.e. typical voltage) of battery discharge during use, while 4.2V refers to the voltage when fully charged. The common rechargeable 18650 lithium battery has a voltage of 3.6 or 3.7v. When fully charged, it is 4.2v. This has little to do with the power (capacity).
The mainstream capacity of 18650 batteries ranges from 1800mAh to 2600mAh (the capacity of 18650 power batteries is mostly 2200~2600mAh). The mainstream capacities even have 3500 or 4000mAh or more.
It is generally believed that when the no-load voltage of a lithium battery is lower than 3.0V, it is considered to be exhausted (the specific value depends on the threshold value of the battery protection board, such as as low as 2.8V and 3.2V). ). When discharging most lithium batteries, the no-load voltage cannot be lowered below 3.2V, otherwise excessive discharge will damage the battery (generally, lithium batteries on the market are basically used with protective plates, so excessive discharge will also cause the protective plate to fail to detect to the battery, making it impossible to charge the battery).
4.2V is the maximum limit voltage for battery charging. It is generally believed that the lithium battery is fully charged when its no-load voltage reaches 4.2V. During the battery charging process, the battery voltage gradually rises from 3.7V to 4.2V. When charging lithium batteries, the no-load voltage cannot be charged above 4.2V, otherwise the battery will be damaged. This is the special thing about lithium batteries.
Reference for the above content: Baidu Encyclopedia-18650 lithium battery