Dongguan Greenway Battery Co.,Ltd.
FAX：(+86) 769 2229 0098
ADD：Xinyuan Road, Tongsha Industry Park, Dong
Cheng District, Dongguan, China
18650 battery manufacturers take you to understand the purchase of 18650 lithium batteries
18650 is a battery model that specifies the external dimensions of the battery, but does not specify the battery capacity. Therefore, the 18650 batteries produced by different manufacturers have different battery capacities. However, the 18650 battery is generally marked with the battery capacity. When purchasing 18650 batteries, the merchant will also indicate the battery capacity. The mainstream capacity of the 18650 battery is 1800mAh~3500mAh, and a small part has a nominal capacity of more than 4000mAh.
18650 is a standard lithium-ion battery model set for cost saving at the beginning of the lithium-ion battery, in which 18 means a diameter of 18mm, 65 means a length of 65mm, and 0 means a cylindrical battery.
There are two nominal voltages of 18650 battery on the market, 3.7V and 4.2V. These two nominal 18650 batteries are actually the same. This is only the voltage marked by the manufacturer is different. 3.7V refers to the typical voltage when the battery is discharged during use, and 4.2 refers to the voltage when the battery is fully charged.
Under normal circumstances, when the no-load voltage of the lithium battery is discharged below 3V, it is considered that the battery power has been used up, and excessive discharge will damage the battery. It is generally believed that charging the no-load voltage of the lithium battery to 4.2V is considered to be fully charged. The lithium battery cannot be charged to the no-load voltage above 4.2V, otherwise the battery will be damaged.
Therefore, when using the 18650 self-made lithium battery pack, the charging protection circuit and discharge protection circuit of the battery must not be ignored (the 18650 battery manufacturer tells you that the discharge voltage cannot be lower than 3V, and the charging voltage cannot be higher than 4.2V).