As a manufacturer of high-quality lithium iron phosphate (LFP) batteries, FoxESS often receives enquiries about battery degradation over time. Understanding how batteries lose capacity with extended use is essential for homeowners and businesses considering energy storage solutions. This article explores the degradation of LFP battery cells, using real-world data and scientific explanations to provide a comprehensive overview.
What Causes Battery Degradation?
All batteries degrade over time—it’s just part of the chemistry. With each charge and discharge cycle, small changes occur inside the battery that slowly reduce its ability to hold a full charge. The good news is that LFP batteries are among the most durable lithium-ion options available, which is why they’re widely used for home energy storage.
The key factors affecting battery lifespan include:
- Charge/Discharge Cycles – Every time you charge and use your battery, it goes through a cycle. Over thousands of cycles, this gradually reduces capacity.
- Depth of Discharge (DoD) – This refers to how much of the battery’s energy is used before recharging. Shallower cycles (e.g., discharging to 10-20% instead of 0%) help extend battery life.
- Charge Rate (C-rate) – The speed at which the battery is charged and discharged affects longevity. Slower charging is generally better for long-term performance.
- Temperature – Extreme heat or cold can accelerate wear and tear. Our data assumes a stable 25°C, but real-world conditions may vary.
- Storage & Resting Conditions – If a battery sits unused for long periods, it may degrade differently than one in regular use.
What the Data Shows
We’ve tested our LFP batteries under controlled conditions (0.5C charge/discharge, 90% DoD, 25°C ambient temperature) and observed the following trends:
- 80% SOH (State of Health) at 3,750 cycles – The battery retains 80% of its original capacity.
- 70% SOH at 5,860 cycles – Capacity continues to decline, but the battery remains highly functional.
- 60% SOH at 7,740 cycles – The battery still operates but has lost a notable portion of its original storage capability.
This is in line with what you’d expect from a well-built LFP battery, but real-world results will vary depending on usage habits and environmental factors.
Why LFP Batteries Are a Great Choice
Compared to other lithium-ion chemistries like NMC (Nickel Manganese Cobalt) or NCA (Nickel Cobalt Aluminium), LFP batteries offer several key advantages:
- Longer Lifespan – LFP batteries can easily exceed 6,000 cycles, while NMC batteries typically last 2,000–3,000 cycles.
- Safer Chemistry – LFP cells are far more stable and less prone to thermal runaway, making them safer for home energy storage.
- Better for the Environment – LFP batteries contain no cobalt or nickel, which reduces environmental impact and ethical concerns.
- More Temperature Tolerant – They perform well across a wider temperature range, reducing the risk of overheating or cold-related performance drops.
- Consistent Power Output – LFP cells deliver stable voltage, ensuring reliable energy storage over time.
Maximising Battery Life
To maximise the lifespan of an LFP battery:
- Keep it within a moderate temperature range where possible (10°C – 30°C).
- Avoid excessive charging or discharging beyond recommended limits.
- Implement partial charging cycles where possible instead of full charge/discharge cycles – this will occur naturally with PV charging.
A Quick Disclaimer
While these figures give a solid estimate of battery longevity, real-world performance depends on various factors, including how the battery is used, environmental conditions, and individual cell variations. Our lab tests provide a reliable benchmark, but actual results may differ.
Final Thoughts
LFP batteries are one of the best choices for energy storage, offering safety, longevity, and reliability. Understanding degradation helps you manage your system effectively and maximise its lifespan. If you have any questions or need guidance on the right battery for your needs, our team is always happy to help.
