[Full Guide] The Comprehensive Guide to LiFePO4 Battery Life

As the world transitions to clean and sustainable energy sources, Lithium-Ion (Li-ion) batteries have gained significant popularity. Renowned for their high energy density and long lifespan, these batteries have revolutionized the industry. However, many users often wonder, "How long do Lithium-Ion batteries last?" In this article, we will explore this question and examine how LiFePO4 batteries, an advanced type of Lithium-Ion battery, compare in terms of lifespan.

Table of Content

• Part 1. What are lithium-ion batteries?
• Part 2. How Long Do Lithium-Ion Batteries Last?
• Part 3. Factors that influence the lifespan of lithium-ion batteries
• 3.1 During Storage
• 3.2 During cycling
• Part 4. Methods to Prolong the Li-ion battery lifespan
• Part 5. FAQs about Li-ion Battery
• Part 6. Is the Investment in Lithium-Ion Batteries Worth It?

Part 1. What are lithium-ion batteries?

Lithium-ion batteries, including Lithium iron phosphate (LiFePO4) batteries, are rechargeable and utilize lithium ions as the primary component of their electrolyte. LiFePO4 batteries offer several advantages over other types of batteries, such as a longer lifespan, higher efficiency and energy density, lower maintenance requirements, enhanced safety, and environmental friendliness. These qualities make them ideal for off-grid power systems, high-powered applications, and mobility solutions.

Li-ion batteries are commonly used as starting batteries in vehicles due to their high energy density and lightweight nature. They are well-suited for this application because they can provide a short burst of high current to start the engine. However, Li-ion batteries used as starting batteries are usually of smaller capacity and should not be discharged too deeply to avoid damage.

In contrast, LiFePO4 batteries excel as deep-cycle batteries. They can withstand frequent, deep discharges, making them ideal for renewable energy storage and other deep-cycle applications. With a longer cycle life than Li-ion batteries, LiFePO4 batteries can deliver high-power performance over extended periods. Learn more differences between these 2 kinds of battery from Differences On Marine Deep Cycle And Starting Battery.

Part 2. How Long Do Lithium-Ion Batteries Last?

On average, a standard Li-ion battery lasts 2-3 years, depending on its usage. With proper maintenance and adherence to the manufacturer's instructions, this lifespan can extend up to five years. Li-ion batteries are sensitive to temperature, and high temperatures can significantly reduce their lifespan. Therefore, storing your Li-ion battery in a cool, dry place is crucial to avoid heat exposure and prolong its life.

LiFePO4 batteries represent a more advanced and sustainable type of Li-ion battery, gaining increasing popularity in the industry. These batteries have a longer lifespan than standard Li-ion batteries, lasting up to 10 years or more. Additionally, LiFePO4 batteries are highly stable and safe, providing a more reliable and sustainable solution for off-grid power and mobility applications.

One significant advantage of LiFePO4 batteries is their ability to handle more charge and discharge cycles. While standard Li-ion batteries can manage up to 500-1000 cycles, LiFePO4 batteries can endure up to 2000 cycles, making them a more durable and cost-effective solution in the long run. The Timeusb LiFePO4 battery can handle between 4000 to 15000 cycles, with a lifespan of over 10 years, making it an ideal alternative to lead-acid deep cycle batteries. Additionally, LiFePO4 batteries are much safer than standard Li-ion batteries, as their chemical composition makes them less prone to overheating or exploding.

Timeusb offers high-quality LiFePO4 batteries designed for longevity, efficiency, and sustainability. Our range of battery sizes and capacities is suitable for various off-grid power and mobility applications. We take pride in the quality and durability of our batteries, thoroughly testing them to ensure customer satisfaction.

Part 3. Factors that influence the lifespan of lithium-ion batteries

According to the research A STUDY OF THE FACTORS THAT AFFECT LITHIUM ION BATTERY DEGRADATION, here are the factors that could influence the lifespan of lithium-ion batteries.

3.1 During Storage

1) Temperature

The primary cause of battery capacity loss during storage is temperature, with higher temperatures accelerating the thermal decomposition of the electrodes and electrolyte.

Electrolyte decomposition increases the thickness of the solid electrolyte interface (SEI) film on the anode, consuming lithium ions, raising internal resistance, and reducing battery capacity. This decomposition also generates gases, which increase internal pressure and pose safety risks. As shown in Table 3.1, Li-ion batteries stored at the same state of charge (40%) lose varying percentages of their capacity over one year at different temperatures.

The degree of degradation increases with higher temperatures, with extreme temperatures significantly accelerating capacity loss. For instance, a 25°C increase from 0°C to 25°C results in only a 2% increase in capacity loss, while a 20°C increase from 40°C to 60°C causes a 10% increase in capacity loss.

Table 3.1

Temperatures exceeding 30°C are considered stressful for Lithium-ion batteries and can lead to substantial calendar-life loss. To extend battery life, it is advisable to store Li-ion batteries at temperatures ranging from 5°C to 20°C.

2) State of Charge (SOC)

Li-ion batteries show an increase in open circuit voltage (OCV) as the state of charge (SOC) rises, as illustrated in Figure 3.2. When stored, a higher battery SOC results in a higher OCV. However, elevated OCV can lead to the growth of the solid electrolyte interface (SEI) and trigger electrolyte oxidation, causing capacity loss and increased internal resistance (IR).

Figure 3.2

Figure 3.3 illustrates the varying degradation rates of Li-ion batteries at different SOC levels over ten years of storage. As SOC levels increase, the remaining capacity of Li-ion batteries diminishes more rapidly.

Figure 3.3

To minimize battery degradation and extend lifespan, it is advisable to keep Li-ion batteries at a moderate SOC level. Charging or discharging Li-ion batteries to around 50% SOC before storing them is recommended.

3.2 During cycling

1) Temperature

While higher temperatures during battery operation can temporarily boost performance, prolonged cycling at elevated temperatures shortens battery lifespan. For example, a battery operating at 30°C experiences a 20% reduction in cycle life, and at 45°C, its lifespan is halved compared to operation at 20°C.

Manufacturers recommend a nominal operating temperature of 27°C to optimize battery performance. On the other hand, extremely low temperatures increase internal resistance and reduce discharge capacity. A battery that delivers 100% capacity at 27°C (80°F) provides only 50% capacity at -18°C (0°F).

The discharge capacity of lithium polymer cells varies with temperature, showing lower capacities at low temperatures (0°C, -10°C, -20°C) compared to higher temperatures (25°C, 40°C, 60°C). Charging Li-ion batteries at low temperatures (below 15°C) can cause lithium plating due to the slowed intercalation of lithium ions, which accelerates battery degradation by increasing internal resistance and further reducing discharge capacity.

Figure 3.4

To maximize the lifespan and performance of Li-ion batteries, it is recommended to operate them at moderate temperatures. A temperature of 20°C or slightly below is optimal for achieving maximum service life. However, for maximum battery runtime, manufacturers suggest a slightly higher temperature of 27°C.

2) Depth of Discharge

Depth of discharge (DOD) significantly affects the cycle life of Li-ion batteries. Deep discharges create pressure within the cells and damage the negative electrode sites, which accelerates capacity loss and increases the risk of cell damage. As shown in Figure 3.5, deeper discharge cycles result in a shorter battery lifespan.

Figure 3.5

Discharge depths exceeding 50% are considered deep discharges. When a Li-ion battery’s voltage drops from 4.2V to 3.0V, approximately 95% of its energy is depleted, leading to the shortest possible battery life with continuous cycling. To minimize capacity loss, it is advisable to avoid full discharges during battery use. Partially discharging and recharging Li-ion batteries can help extend their lifespan.

Manufacturers usually rate a battery based on the 80% depth of discharge (DOD) formula, meaning that only 80% of the available energy is used during operation, with the remaining 20% reserved to prolong battery life. While reducing DOD can extend cycle life, an excessively low DOD may lead to insufficient battery runtime and the inability to complete certain tasks. For optimal lifespan and performance, a DOD of around 50% is recommended for Li-ion batteries.

3) Charge voltage

Li-ion batteries can achieve high capacity and extended runtime with elevated charge voltages. However, fully charging them is not advisable as it can lead to lithium plating, which results in capacity loss, potential battery damage, and increased risk of fires or explosions.

Figure 3.6

Figure 3.6 demonstrates capacity degradation at high charge voltages (>4.2V per cell), showing that higher voltages lead to faster capacity loss and reduced cycle life. The recommended charge voltage for optimal capacity and safety is 4.2V. Reducing the charge voltage by 70mV can lower overall capacity by approximately 10%.

Table 3.2 shows that the cycle life is longest (2400-4000 cycles) at a charge voltage of 3.90V and is halved with each 0.10V increase in charge voltage within the range of 3.90V to 4.30V.

Table 3.2

To prevent significant degradation of Li-ion batteries, they should be charged to a voltage level below 4.10V. While a lower charge voltage can extend battery life, it results in reduced runtime. Additionally, discharging below 2.5V per cell should be avoided, and a charge voltage of 3.92V is optimal for achieving the longest cycle life. This is why Timeusb does not recommend using a standard lead-acid charger for LiFePO4 batteries, as it provides insufficient voltage for proper charging.

The recommended charging voltage varies depending on the type of deep-cycle battery system. For electronic devices like laptops and cell phones, a higher voltage threshold is used to maximize battery runtime. In contrast, large energy storage systems for satellites or electric vehicles use a lower voltage threshold to extend battery life. Regardless of the application, overcharging Li-ion batteries can significantly reduce their lifespan and pose safety risks, such as fires or explosions, and thus requires careful management.

4) Charge current/ C-rate

Li-ion batteries face several negative effects when subjected to high C-rates, including increased internal resistance, reduced available energy, safety concerns, and irreversible capacity loss.

A major consequence of high C-rates is lithium plating. Charging a Li-ion battery with high current causes lithium ions to migrate rapidly, resulting in the accumulation of lithium on the anode surface and the formation of metallic lithium. This issue is worsened when batteries are fast-charged at low temperatures or high state-of-charge (SOC).

The deposited lithium can form dendritic structures, which increase the battery's self-discharge rate and, in severe cases, lead to short circuits and potential fires. Additionally, high charge and discharge currents lead to greater energy loss due to internal resistance, converting energy into heat. When the C-rate exceeds the battery’s recommended level, the increased temperature can stress the battery, causing damage and accelerating capacity loss.

5) Cycle frequency

Frequent cycling of Li-ion batteries, especially when occurring four or more times per day, can induce mechanical stress and promote the growth of the Solid Electrolyte Interphase (SEI) layer.

With each cycle, Li-ion batteries experience a loss of both positive and negative lithium reaction sites on the electrodes, which diminishes their capacity. The buildup of the SEI layer increases the battery's internal resistance, reducing electronic conductivity and loading capability.

The thickening of the SEI layer, along with the reduction in lithium reaction sites and other chemical changes within the battery, leads to capacity loss and eventual failure. Although specific research on this issue is limited, it is generally believed that high cycle frequencies accelerate battery degradation due to the elevated temperatures generated by frequent use.

Constantly cycling Li-ion batteries without adequate cooling time can induce chemical stress, leading to the decomposition of electrolytes and electrodes.

Part 4. Methods to Prolong the Li-ion battery lifespan

To maximize the lifespan of Li-ion batteries, follow these guidelines:

1. Maintain moderate temperatures: High temperatures can shorten battery lifespan. It is advisable to store or use Li-ion batteries within a moderate temperature range of 5°C to 20°C.

2. Partial discharge and charging: Partially discharging and charging Li-ion batteries, rather than fully cycling them, can extend their lifespan. Avoid deep discharges exceeding 50% DOD to help prolong battery life.

3. Keep SOC levels moderate: Extreme state of charge (SOC) levels can lead to capacity loss and reduced battery lifespan. Maintaining Li-ion batteries at an intermediate SOC level helps minimize degradation and extend their life.

4. Avoid heat exposure: High temperatures during use or storage can increase SEI thickness and trigger electrolyte oxidation, resulting in capacity loss and reduced battery lifespan.

5. Store batteries properly when not in use: Keep Li-ion batteries at around 50% SOC and protect them from extreme temperatures and humidity when not in use.

6. Avoid fast charging and discharging: Rapid charging or discharging generates excess heat, which can damage the battery's internal components over time and shorten its overall lifespan.

7. Use original equipment manufacturer (OEM) chargers: Using OEM chargers specifically designed for Li-ion batteries ensures they receive the correct voltage and current, preventing damage and extending their lifespan. Timeusb offers suitable LiFePO4 battery chargers, ensuring proper charging for LiFePO4 lithium batteries.

Part 5. FAQs about Li-ion Battery

1. How long do lithium battery last in cars?

The lifespan of lithium batteries in cars depends on various factors, including battery quality, usage patterns, and environmental conditions. Typically, a well-maintained lithium battery in a car can last between 8 to 10 years or even longer.

However, this lifespan can vary based on factors such as how often the car is used, charging habits, ambient temperature, and driving style. To maximize lifespan and performance, it is crucial to adhere to the manufacturer's guidelines for battery maintenance and charging.

2. How long do lithium battery last in golf carts?

A well-maintained lithium battery in a golf cart generally lasts between 5 to 7 years or more. Timeusb lithium golf cart batteries, with a life cycle of up to 4000-15000 cycles, can last over 10 years.

3. How long can lithium battery last without charging?

The duration a Lithium-ion battery can last without charging depends on factors such as the battery's capacity, the device it powers, and the device's power consumption. On average, most Lithium-ion batteries can last between 2 to 10 years without charging, depending on storage conditions. However, this timeframe can vary based on temperature, usage patterns, and storage conditions. To maximize lifespan, proper storage and maintaining the recommended state of charge (SOC) are crucial. Even when not in use, Lithium-ion batteries can gradually lose charge and may need recharging before use.

4. Is LiFePO4 battery safer than lithium ion battery?

Yes, Lithium Iron Phosphate (LiFePO4 or LFP) batteries are considered safer than traditional Lithium-Ion (Li-ion) batteries due to their more stable chemistry. This stability makes them less prone to overheating, thermal runaway, and other safety issues.

LiFePO4 batteries have a lower risk of thermal runaway because they have lower internal resistance, which results in less heat generation and reduces the likelihood of cell damage or explosion. They also offer greater thermal stability and can withstand high temperatures without degrading or losing capacity, making them ideal for applications that require a durable and reliable power source.

Part 6. Is the Investment in Lithium-Ion Batteries Worth It?

Lithium-ion batteries are clearly superior to outdated lead-acid batteries. They are lighter, have a higher power capacity, and exhibit a lower self-discharge rate. Additionally, they require less maintenance and have a longer service life. While the initial cost may be higher, the overall savings are substantial. Therefore, lithium-ion batteries are considered a valuable investment, providing a reliable and low-maintenance solution for storing significant amounts of power, which can be especially advantageous when needed most.