Talk About the Capacity and Battery Life of the 18650 Lithium Battery
What is the maximum capacity of 18650 lithium battery?
Due to the fixed size of 18650 battery, its maximum capacity has been concerned by many practitioners. In recent years, various manufacturers have improved their technology and capacity accordingly. Samsung, Panasonic, LG, SONY and IMREN can achieve 3600mAh or more, but the capacity range of 2600~3000mAh is the best consistency. If it is to do the battery pack best not to use the highest capacity, regardless of cost performance and the life of the battery pack after the group is not very cost-effective. So it is not to say that the higher the cell capacity, the more stable the use, for a long time.
It is worth noting that many buyers will have a misunderstanding that high capacity, the actual discharge current will be large, but this is just the opposite: 18650 lithium battery is generally divided into capacity type and rate type, capacity type mainly reflects the large capacity, but the discharge current is generally lower than 1C, the current is small; Multiplier type can discharge large current, but the capacity is low, the use time is not long. It's like having your cake and eating it too.
In a word, the price of 18650 lithium battery is proportional to the size of capacity. The greater the capacity, the greater the energy ratio, the more raw materials used, so the price will be more expensive
How long is lithium battery life?
Now 3.7V 18650 lithium battery general cycle life can reach 500~1000 times, 3.2V 18650 general life can reach more than 2000, of course, the premise is the qualified battery produced by regular manufacturers, if it is defective or fake battery, life will be very short.
The life of 18650 lithium battery is 300 ~ 500 charging cycles. Assuming that the power provided by a complete discharge is Q, if the reduction of the power after each charging cycle is not considered, the lithium battery can provide or supplement 300Q-500Q power in its lifetime. From this, we know that if we charge each time with 1/2, we can charge 600-1000 times; If one third of each charge is used, 900 to 1,500 charges can be made. And so on, if the charge is random, the number of times is variable.
In short, no matter how it is charged, a total of 300Q to 500Q of power is added, which is constant. Therefore, we can also understand: lithium battery life is related to the total charge of the battery, and the number of charges has nothing to do with. There is little difference between deep charge and shallow charge on lithium battery life.
The theoretical life of ternary lithium battery is about 800 cycles, which is in the middle of commercial rechargeable lithium battery. Lithium iron phosphate is about 2,000 cycles, while lithium titanate is said to reach 10,000 cycles. At present, the mainstream battery manufacturers in its production of three core specifications committed more than 500 times, but the core in the battery pack, because of the consistency of the problem, mainly voltage and internal resistance can not be exactly the same, its cycle life is about 400 times.
Above is the price of 18650 lithium battery, 18650 lithium battery life analysis. The low cost of 18650 lithium battery determines its market share, so we hope to choose 18650 battery for cheap, and we hope to choose lithium polymer battery for thin and light.