Cylinder Battery The energy density of the 21700Li ion cell is better than that of the 18650 battery. Under existing conditions, the energy density of its 21700 battery system is about 300Wh/kg, which is about 20% higher than the 250Wh/kg of its original 18650 battery system. Using 21700Li ion cell, the increase in energy density of a single battery is much higher than the 20% increase after grouping. After switching to the new 21700 battery, the system can reduce components and weight by 10% compared with the existing battery, thereby further reducing the weight of the battery pack, and the energy density of the entire vehicle will also be partially improved. Battery cost reduction is based on yield. Diameter 21mm Length 70mm Weight: about 65g Rated voltage: 3.6V Standard capacity: 4800mAh-5000mah To sum up, the size is increased from 18650 to 21700, and the benefits are as follows: 1) When the energy density is appropriately increased, conventional materials can be selected, with stable performance and high cost performance; 2) The multi-pole ear mechanism can be designed appropriately to reduce the internal resistance; 3) Under the same energy density, graphite with fast charging characteristics can be selected to improve fast charging performance; 4) Appropriately increase the diameter and height to obtain more effective volume. 5) The capacity of the single cell is increased, the proportion of auxiliary components is reduced, and the cost of the pack is reduced.Cylinder Battery website:http://www.ionli-battery.com/li-ion-battery-cell/cylinder-battery/