The difference between 18650 and 21700 lithium batteries and which one is better to use? I believe many people have questions, today I will answer them with everyone!
1、 18650 battery
18650 batteries basically refer to lithium batteries, which can be divided into ternary lithium, lithium iron phosphate, and lithium titanate according to materials. The common 18650 is a ternary lithium battery with a capacity range of 2000-3000. Currently, the highest 18650 can achieve 3500mAh, where 18 refers to the diameter of the battery, 65 refers to the height, and 0 refers to the cylinder. All units are in millimeters.
At the beginning, Tesla Power also chose 18650 battery cells. At that time, there were more than 7000 18650 batteries, and the large number of battery cells posed a very strict challenge to the battery management system. Therefore, they chose to use 5000mAh 21700 battery cells. As the capacity increased, the number of battery cells decreased, which made the requirements for BMS less challenging;
2、 21700 battery
At present, most 21700 battery cells are ternary, and I have not encountered 21700 with lithium iron or lithium titanate. Currently, the highest 21700 can achieve 5000mAh. 21 refers to the diameter of the battery, 70 refers to the height, and 0 refers to the cylinder, all in millimeters;
3、 Good consistency of battery cell grouping
Before Tesla's new energy vehicles, 18650 batteries had already been used in many battery products and were one of the earliest, most mature, and stable lithium-ion batteries.
Compared to other batteries, such as stacked lithium-ion batteries, they are far from mature. Many products cannot even be standardized in size, dimensions, etc., and the production processes possessed by battery manufacturers cannot meet the conditions.
Overall, the consistency of batteries cannot reach the level of 18650 batteries. If the consistency of batteries does not meet the requirements, the management of a large number of batteries connected in series or parallel to form a battery pack will not be able to better utilize the performance of each battery. However, 18650 batteries can effectively solve this problem!
