How long do FTM battery storage systems typically last?
Modern lithium-ion FTM systems are designed for 15-20 year operational lifespans with gradual capacity degradation over time.
Most FTM battery storage systems use lithium-ion technology (specifically lithium iron phosphate, or LFP) and are designed for a 15-20 year operational life. However, "lifespan" in battery storage isn't a simple on/off — it's about degradation.
Batteries lose capacity over time with each charge-discharge cycle. A system rated at 100 MWh at installation might retain 70-80% of that capacity after 15 years, depending on how aggressively it's cycled. Most FTM projects are warranted for a specific number of cycles or years at a guaranteed minimum capacity (often 70% of original capacity after 15 years).
Key factors affecting lifespan include cycling depth (deeper discharges degrade batteries faster), cycling frequency (more cycles per day means faster degradation), temperature management (heat is the enemy of battery longevity — well-designed thermal management systems are critical), and charge rate (faster charging generates more heat and accelerates degradation).
Augmentation strategies — adding new battery modules over the project's life to maintain total capacity — are common in long-duration contracts. Project developers typically model augmentation costs into their financial projections.