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Lithium-ion batteries power many devices and technologies we rely on daily, from smartphones and tablets to portable power stations. Their lightweight design, high energy density, and recharging abilities have made them become a vital energy source. But how long can these batteries last, and what factors influence their longevity? Understanding the life cycle of lithium batteries and what affects their lifespan can help you get the most out of your investment.
Let’s learn how.
What Is Lithium Battery Cycle Life?
A lithium battery’s cycle life simply refers to how many charge and discharge cycles it can go through before its capacity drops to a specific point.
When you discharge the batteries, lithium ions move from the negative to the positive electrodes via an electrolyte. When you recharge them, the ions move in the reverse direction. However, every time you go through one of these charge-discharge cycles, the battery slowly degrades and loses capacity over time.
So, we report the cycle life of the different models, typically based on when the capacity is expected to drop to about 80%. They can still be used longer, sometimes years longer, but the capacity continues to reduce.
Most lithium-ion models, also called Li-ion, have a cycle life in the 2000 – 10,000 range, compared to lead-acid models, which may only have 500 cycles.
What’s the Expected Lifespan of Lithium-Ion Batteries?
There are different types of lithium-ion batteries, and their lifespan varies. Cheaper models, often used in cell phones and power tools, last 2-7 years. Others last much longer. For instance, EcoFlow batteries use the newer Lithium Iron Phosphate chemistry, also called LiFePO4 or LFP, in their EcoFlow Portable Power Stations.
These come with a 5-year warranty, no charge cycle restrictions, and last 10-15 years or more. You can use them as a battery backup or add some solar panels and use them as a portable solar generator for an off-grid energy solution.
How Do You Calculate the Cycle Life of Lithium Batteries?
The cycle life depends on several factors, and it’s impossible to calculate it precisely. Still, we can estimate it. First, look at your model’s specs, including its capacity in watt-hours (Wh) or ampere-hours (Ah), discharge rate, the manufacturer’s suggested cycle life, and the depth-of-discharge (DoD), which is the amount of capacity you can use in each cycle.
For example, if you have a 1000Wh model with a depth of discharge of 80%, then you can estimate using this equation:
Life (in cycles) = Capacity / (Discharge rate x Depth of discharge).
Say you are using 100Wh (the discharge rate); your cycle life will be:
1000Wh / (100Wh x 0.8) = 125 cycles.
This is a theoretical example. Remember that it will be affected by temperature, storage, battery management, and charging/discharging rates.
How Charging Cycles Affect Lithium-Ion Battery Capacity
Charging cycles can significantly affect capacity because each time a battery is discharged and charged, it slowly degrades the internal components, resulting in a gradual decrease in capacity over time.
Fortunately, solar batteries have a unique chemistry that allows them to be recharged much more often than traditional lead-acid models that may need replacing every few years. For instance, the EcoFlow DELTA Series Portable Power Stations will last 5-10 years before you see any significant capacity reduction and can last even longer.
What Other Factors Affect Lithium-Ion Battery Capacity?
Temperature
Temperature is one of the most significant factors that can degrade batteries and shorten their lifespan. High temperature accelerates the chemical reactions within, resulting in a faster discharge and faster degradation. Extreme cold slows down those chemical reactions and reduces its capacity. The more exposure to extreme cold or heat, the faster they lose capacity.
Overcharging
Overcharging is a significant problem that also degrades the battery, reducing its capacity faster. This is largely due to excess heat that builds up when the battery is full, and excess energy has nowhere else to go. Overcharging older Li-ion models sometimes resulted in that potentially dangerous thermal runaway you may have heard of.
However, newer models, especially high-quality LiFePO4 battery chemistry, are safer and usually have a system to prevent overcharging.
For instance, the EcoFlow DELTA Pro has a built-in battery management system that will help prevent overcharging, extending the lifespan of your portable power station. Their LiFePO4 chemistry is also more stable and not prone to thermal runaway.
Storage
Storage conditions can also affect capacity. This is mainly related to those temperature extremes we already discussed. Store them in a cool, dry location that will not freeze but does not get too hot; a garage or basement often works best. Also, storing them at partial charge is best since fully charged or fully discharged can accelerate degradation.
Fast Charging
Fast charging may cause heating and accelerate battery degradation. So, if you always use fast charging, your batteries could degrade faster. For products that use fast charging, always use the original recommended charger.
Discharge Rate
Discharge rate is how you use the battery. If you draw high loads or use them continuously, they will degrade faster than if they were used with lighter loads or used more intermittently.
How To Prolong Lithium Battery Life
Li-ion batteries last, on average, 2 to 10 years, depending on environmental factors, usage patterns, and the particular chemistry of your model. For instance, LiFePO4 models last the longest, on average, 5 – 15 years, while Lithium-polymer models may only last 2 to 5 years.
To prolong its lifespan, avoid extreme heat or cold and store it in a cool, dry location when not in use. When in storage, aim to keep it partially charged; fully charged and fully discharged batteries will degrade faster than partially charged ones. Also, avoid storing it for extended periods if possible; regular use keeps it active and healthy.
Always avoid overloading your batteries when in use. Drawing more power than they are designed to handle can cause overheating, which may damage them and reduce their lifespan. Purchase a battery with more capacity than you need to avoid that issue. Also, avoid physically damaging and protecting them from moisture, reducing their lifespan.
Finally, watch their charging closely and always use the manufacturer’s original or recommended charger. Avoid too much fast charging, even if your system is designed to handle it. Also, do not discharge them fully as that reduces their capacity faster, and avoid overcharging, which can damage the electrodes. If yours has a battery management system (BMS), use it to monitor your charge cycles. If yours does not have a BMS, always unplug it when it reaches full capacity.
The EcoFlow DELTA Pro 3 has enough capacity to be used as a whole-home generator, especially since its capacity is upgradeable by adding extra storage batteries so you won’t overload them. Combine it with EcoFlow Power Kits for easy integration into your RV or off-grid building. It also has a BMS that you can monitor on your smartphone app to optimize its lifespan.
Frequently Asked Questions
No, they will not. However, they will slowly self-discharge, which can take months to years, depending on the model, quality, and capacity. Do not leave them unused for too long; their capacity and lifespan can be reduced if they completely self-discharge.
Lithium batteries generally have a very slow self-discharge rate, allowing them to hold a charge much longer than older models. However, it depends on the model, quality, and capacity. Generally, they should keep a charge for at least 2-6 months or up to a few years.
Yes, many of them can. It depends on the type of battery chemistry and the quality of the battery, which can vary significantly depending on the manufacturer. However, a quality LiFePO4 battery should last at least 10 years.
Final Thoughts
Lithium-ion batteries are essential for modern life, offering impressive longevity and performance, especially with advancements like LiFePO4 technology. You can maximize their lifespan and efficiency with proper care—such as avoiding extreme temperatures, overcharging, and using recommended chargers.
Whether powering your devices, providing essential backup, or enabling off-grid adventures, LiFePO4 batteries deliver reliability and durability for many years. Explore EcoFlow DELTA Series Portable Power Stations to find the perfect fit for your energy needs.