“6000 cycles @ 80% DOD” is the headline figure on almost every LiFePO4 battery datasheet. Understanding what it really says helps you compare products honestly and predict service life.
Cycle Life and Depth of Discharge
One cycle is one full charge-and-discharge. DOD — depth of discharge — is how much of the battery’s energy is used in that cycle. The rating means: after 6000 cycles, each using 80% of the battery’s capacity, the battery still retains at least 80% of its original capacity.
Translating Cycles Into Years
In a typical solar home the battery cycles once per day. 6000 daily cycles equals more than 16 years of use — and even then the battery is not dead, just at roughly 80% of its original capacity. A comparable lead-acid battery at 400–600 cycles would need replacing five to ten times over the same period, which is why the cost per kWh delivered favors LiFePO4 so strongly.
- LiFePO4: ~6000 cycles @ 80% DOD (16+ years daily cycling)
- Deep-cycle AGM: ~400–600 cycles @ 50% DOD
- GEL: ~800–1200 cycles @ 50% DOD
Why Test Conditions Matter
Cycle ratings are measured at defined temperature and current, typically 25°C and 0.5C. Extreme heat and sustained high currents shorten life. This is why PATTERN publishes the test conditions alongside the rating and designs the BMS to protect against both stress factors.
