How to make your 18650 battery cycle life longer?

18650 batteries are widely used in various electronic devices due to their high energy density and long cycle life. However, the number of cycles of a battery is not fixed and is affected by many factors. This article will analyze these factors in detail and provide practical suggestions for extending battery life.

I. Definition of the number of cycles of 18650 batteries

The number of cycles refers to the process of a battery completing a 100% charge and discharge. For example, a battery is used from 100% to 50% and then fully charged to 100%, which is only counted as 0.5 cycles.

II. Factors affecting the number of cycles of 18650 batteries

1. Battery quality:
   High-quality batteries use high-quality materials and advanced processes, and the number of cycles can reach more than 500 times, while inferior batteries may only have 200-300 times.
2. Depth of charge and discharge (DOD):
   Deep discharge (such as less than 20%) will accelerate battery aging, while shallow charge and discharge (such as maintaining at 20%-80%) will help extend the cycle life.
3. Charge and discharge rate (C-rate):
   High-rate charge and discharge will generate more heat and damage the internal structure of the battery. It is recommended to use a charge and discharge rate below 1C.
4. Working temperature:
   High temperature will accelerate the chemical reaction inside the battery, resulting in capacity decay. The optimal working temperature is 20°C to 25°C.
5. Battery Management System (BMS):
   High-quality BMS can effectively prevent overcharging, over-discharging, overcurrent and other problems, and extend the battery life.

III. How to extend the cycle life of 18650 batteries

1. Choose high-quality batteries:
   Buy 18650 batteries from well-known brands with good reputations to avoid inferior products.
2. Avoid deep charge and discharge:
   Try to keep the battery power between 20%-80% to avoid overcharge and over-discharge.
3. Control the charge and discharge rate:
   Use a charger that matches the battery specifications to avoid fast charge and discharge.
4. Maintain a suitable working temperature:
   Avoid the battery working in high or low temperature environments, and use heat dissipation or insulation measures when necessary.
5. Use equipment with BMS protection:
   Choose equipment with BMS protection to prevent battery overcharge, over discharge, over current and other problems.

IV. Summary

The number of cycles of 18650 batteries is affected by many factors, usually between 300-500 times. By choosing high-quality batteries, using and maintaining them properly, you can effectively extend the battery life and improve the user experience.