Factors That Affect The Life Cycle of LiFePO4 Batteries

LiFePO4 battery as a leader in lithium battery technology, because of its excellent safety and long life attention. When choosing and using a LiFePO4 battery, it is important to understand its cycle life and the factors that affect it. Below we will explore the cycle life of a LiFePO4 battery and the various factors that affect its life.

First, let's understand what is cycle life? Cycle life refers to how many full charge and discharge cycles a battery can complete while maintaining its rated capacity. In other words, it measures the rate at which the battery gradually wears out over the course of use. Cycle life provides a more accurate and realistic assessment of life expectancy than life measured in years alone.

It should be noted that the cycle life of the LiFePO4 battery and the depth of discharge (DOD) of the battery are closely linked. (DOD indicates the depth of discharge, DoD=100% indicates that the battery is fully charged, DoD=80% indicates that the battery will discharge 80% of its rated capacity, that is, 20% of the remaining rated capacity) Take the battery cell used by our AT22 as an example:

Cycle life (100%DOD) ≥2000 times

Cycle life (80%DOD) ≥3500 times

Many cells on the market do not mark the depth of discharge when describing the cycle life, and such cycle life without marking the depth of discharge needs to be carefully considered.

Because of its excellent cycle life, LiFePO4 batteries are the first choice for many applications, such as AGVs, UPS, starter batteries, medical devices, golf carts, home storage/solar energy storage systems, and more.

However, even for users of the same brand with the same capacity battery, there will be some differences in its cycle life, so the factors affecting the cycle life of the battery are worth our attention. Here are some of the main factors.

Battery type: The cycle life of the battery depends on the battery chemical composition, the following is the average cycle life value of the battery with different chemical composition:

Lead-acid battery: 300 cycles

Nickel-cadmium battery: 500 cycles

Nimh battery: 800 cycles

Lithium-ion battery (cobalt) : 1000 cycles

Lithium-ion battery (manganese) : 800 cycles

LiFePO4 battery: 2000 cycles

Charge and discharge mode: The charge and discharge mode affects the life of the LiFePO4 battery. Overcharging and discharging can cause permanent damage to the battery, thereby shortening the battery life. Therefore, it is necessary to use a manufacturer's charger to provide the correct voltage and current for the battery.

Temperature: LiFePO4 battery life is affected by temperature. High temperature will accelerate the aging process of the battery, resulting in the shortening of cycle life; Too low a temperature can also affect the reaction rate of the LiFePO4 battery. Therefore, use within the specified operating temperature range of the battery is essential to extend the life of the LiFePO4 battery.

Storage conditions: Due to the nature of lithium batteries, there will be a slight self-discharge when not used for a long time, so when the batteries are not used for a long time, they should be stored at room temperature, the power is maintained at 40%-60%, and it is recommended to charge once every 3 months to avoid LiFePO4 batteries in a fully discharged state to ensure their health. For more specific maintenance, please follow the LiFePO4 battery operation instructions and precautions provided by the manufacturer.

In summary, cycle life is an important indicator for evaluating the life of a LiFePO4 battery. Understanding the factors that affect cycle life, such as the type of battery, how it is charged and discharged, temperature, and storage conditions, helps to maximize the life of a LiFePO4 battery. When choosing and using LiFePO4 batteries, be sure to follow the manufacturer's usage and maintenance guidelines to ensure optimal performance and extended service life.