The recommended depth of discharge for lithium iron phosphate batteries (LIFePO4 batteries) is usually about 80%. This means that in normal use, it is ideal for the battery to discharge from full charge (100%) to 20%. This can extend the cycle life of the battery and reduce the deterioration of battery performance caused by excessive discharge.

The definition of discharge depth

• Depth of Discharge (DOD, Depth of Discharge) : refers to the percentage of the capacity released by a battery during a discharge to the total capacity. For example, if a 100Ah battery discharges to 80Ah, its discharge depth is 80%.

Reasons for recommended discharge depth

1. Extend battery life: Frequent deep discharge will accelerate the aging of the battery internal materials and shorten the cycle life of the battery. Maintaining an appropriate depth of discharge can significantly extend battery life.

2. Improve safety: Excessive discharge may cause damage to the internal structure of the battery, increasing safety risks.

3. Optimize performance: In a reasonable discharge depth range, the battery charge and discharge efficiency and stability are higher, and can better meet the needs of equipment.

Suggestions for practical applications

• Electric vehicles: To ensure long-term battery performance and safety, many electric vehicle manufacturers recommend a depth of discharge of no more than 80%.

• Energy storage systems: In home and commercial energy storage systems, in order to maximize battery life, it is also common to limit the depth of discharge to about 80%.

• Portable devices: For portable electronic devices, although the depth of discharge requirements may be more relaxed, following an 80% depth of discharge still helps to extend battery life.