The Comprehensive Guide to LiFePO4 Voltage Chart

Are you considering LiFePO4 lithium batteries for your next project or application? Understanding the voltage characteristics of these batteries is crucial for their optimal performance and longevity. In this comprehensive guide, we'll delve into the specifics of LiFePO4 lithium battery voltage, providing you with a clear understanding of how to interpret and utilize a LiFePO4 lithium battery voltage chart.

Table of Content

Part 1: Understanding LiFePO4 Lithium Battery Voltage
Part 2: LiFePO4 Voltage Chart: 3.2V, 12V, 24V, 36V & 48V
Part 3: LiFePO4 Battery Charging & Discharging

3.1 Charging LiFePO4 Batteries
3.2 Discharging LiFePO4 Batteries

Part 4: How Does Voltage Affect LiFePO4 Battery Performance?
Part 5: How to Measure Battery Voltage
Part 6: How to Extend the Lifespan of a LiFePO4 Battery
FAQs about Battery Voltage

Part 1: Understanding LiFePO4 Lithium Battery Voltage

Lithium Iron Phosphate (LiFePO4) batteries are recognized for their high safety standards, excellent temperature resistance, fast discharge rates, and long lifespan. These high-capacity batteries effectively store energy and power a variety of devices across different environments. The voltage of LiFePO4 rechargeable batteries varies based on the State of Charge (SOC); as the battery charges or discharges, the voltage changes. Higher voltage in a LiFePO4 battery indicates greater capacity and energy storage.

To better understand LiFePO4 battery voltage, here are some key definitions:

Nominal Voltage: The optimal performance level of the battery is around 3.25V. This is the standard for monitoring charging and discharging.
Storage Voltage: This is the ideal voltage for storing the battery when not in use for an extended period. Maintaining this voltage helps preserve battery health and minimizes capacity loss.
Fully Charged Voltage: This voltage reaches up to 3.65V, which is the maximum safe charging level. Overcharging beyond this point can cause irreversible damage to the battery.
Discharge Voltage: The optimal discharge voltage is 2.5V. Users should avoid discharging below this level, as doing so can harm the battery.
Deep Discharge: When the voltage falls below the recommended threshold, the battery may enter a state of deep discharge, which can lead to permanent damage or render the LiFePO4 battery unusable.

Part 2: LiFePO4 Voltage Chart: 3.2V, 12V, 24V, 36V & 48V

The LiFePO4 Voltage Chart stands as an essential resource for comprehending the charging levels and condition of Lithium Iron Phosphate batteries.

This visual aid showcases the voltage spectrum from full charge to complete discharge, enabling users to determine the present charge status of their batteries.

It acts as a convenient guide for assessing performance, promoting efficient utilization, and prolonging the lifespan of these reliable and efficient energy storage solutions.

This chart represents a vital tool for the utilization of LiTime's array of LiFePO4-powered products.

State of Charge	3.2V	12V	24V	36V	48V
100%	≥3.65V	≥13.33V	≥26.66V	≥39.99V	≥53.32V
75%	3.4~3.5V	13.3~13.33V	26.6~26.66V	39.9~39.99V	53.2~53.32V
50%	3.2~3.3V	13.15~13.2V	26.3~26.4V	39.45~39.6V	52.6~52.8V
25%	3.0~3.1V	13~13.15V	26~26.3V	39~39.45V	52~52.6V
0%	≤2.5V	10~12V	20~24V	30~36V	40~48V

3.2V LiFePO4 Cell Voltage Chart

Individual LiFePO4 (lithium iron phosphate) cells generally have a nominal voltage of 3.2V. These cells reach full charge at 3.65V and are considered fully discharged at 2.5V.

Understanding the voltage levels is crucial for monitoring battery health and performance.

3.2v lifepo4 battery voltage chart

12V Lithium Battery Voltage Charge

12V LiFePO4 batteries are an excellent upgrade from traditional 12V lead-acid batteries, offering enhanced safety and performance for off-grid solar systems. These lithium iron phosphate batteries provide a more reliable power source, with a longer lifespan and faster charging capabilities.

When fully charged, a 12V LiFePO4 battery reaches a voltage of 14.6V. As the battery discharges, the voltage gradually decreases, reaching 10V when fully discharged. It’s crucial to monitor these voltage levels to ensure optimal performance and longevity of the battery.

12v lifepo4 battery voltage chart

Monitoring the voltage of your 12V LiFePO4 battery is essential to maintaining its health and performance. Avoiding deep discharges (below 10V) and regularly charging to full capacity (14.6V) will help extend the battery’s lifespan and ensure reliable power for your off-grid solar system.

24V LiFePO4 Lithium Battery Voltage Charge

When considering a power solution, you have the option to purchase a 24V LiFePO4 battery or connect two identical 12V LiFePO4 batteries in series. This flexibility allows you to tailor your energy storage system to fit your specific needs, whether for off-grid applications, solar power systems, or electric vehicles.

24v lifepo4 battery voltage chart

A fully charged 24V LiFePO4 battery reaches a voltage of 29.2V. As the battery discharges, the voltage gradually decreases, reaching 20V when fully discharged. Monitoring these voltage levels is crucial for maintaining optimal battery health and ensuring long-term performance.

36V LiFePO4 Lithium Battery Voltage Charge

36V LiFePO4 batteries offer a robust option for various applications, including big trust trolling motor, solar power systems, golf cart and other renewable energy setups. You can either opt for a single 36V LiFePO4 battery or connect three 12V LiFePO4 batteries in series to achieve the desired voltage.

A fully charged 36V LiFePO4 battery reaches a voltage of 43.2V, while it typically discharges to 30V when depleted. Understanding the voltage levels throughout the charging and discharging process is essential for maximizing the performance and lifespan of your battery.

36v lifepo4 battery voltage chart

48V LiFePO4 Lithium Battery Voltage Charge

48V batteries are commonly utilized in larger solar power systems and other high-demand applications. One of the key advantages of using a 48V system is that it allows for lower amperage, which can significantly reduce equipment and wiring costs. This efficiency makes 48V configurations particularly appealing for both residential and commercial solar installations, electric vehicles, and energy storage solutions.

When fully charged, a 48V LiFePO4 battery reaches a voltage of 54.6V. During discharge, the voltage typically drops to 40V when fully depleted. Understanding the voltage levels throughout the charging and discharging cycles is essential for optimizing battery performance and ensuring a long service life.

48v lifepo4 battery voltage chart

Part 3: LiFePO4 Battery Charging & Discharging

Comprehending the charging and discharging processes of LiFePO4 batteries, also known as cycles, is vital for preserving their longevity and effectiveness.

All batteries necessitate specific charging patterns to optimize their lifespan. For LFP battery cycles, a consistent charge up to their full capacity and a controlled discharge that avoids complete depletion is ideal. If you have a battery pack rated at 100Ah and 60Ah of charge remaining, the State of Charge (SoC) would be 60%.

lifepo4 battery's charge and discharge rate curve

Proper management of battery cycles ensures that the battery functions optimally over time, delivering dependable power while safeguarding its health and operational capacity.

But how do charging and discharging work for LiFePO4 batteries? Here’s a detailed breakdown.

3.1 Charging LiFePO4 Batteries:

LiFePO4 batteries typically charge within a voltage range of 3.2V to 3.65V per cell, which means for a 12V (4-cell) battery, the full charge voltage is around 14.6V.

Here's a charging voltage recommend for lithium batteries:

lifepo4 battery charging voltage chart

A. The Core Charging Process: CC/CV Explained

The universally recommended charging method for LiFePO4 batteries is CC/CV (Constant Current / Constant Voltage). This is not a single event but a two-stage process that ensures a fast and safe charge.

lifepo4 lithium battery charging logic cc/cv

Stage 1: Constant Current (CC) – The "Bulk" Charge

This is the first and fastest stage of charging. The charger provides a steady, maximum current (the "bulk" current) which quickly raises the battery's state of charge.

What it is: The charger supplies a constant amperage to the battery.
Voltage: During this stage, the battery's voltage steadily rises from its discharged state.
For a 12V LiFePO4 Battery: This stage continues until the voltage reaches approximately 14.4V to 14.6V.

Stage 2: Constant Voltage (CV) – The "Absorption" Stage

Once the battery hits the peak voltage (e.g., 14.6V), the charging process transitions to the second stage. This is a critical step that many oversimplified explanations miss.

What it is: The charger holds the voltage steady at that peak level (e.g., 14.6V).
Current: Because the voltage is now fixed, the current the battery accepts will gradually decrease.
When is it full? The battery is considered 100% charged when the current tapers off to a very low level, typically 2-5% of the battery's amp-hour capacity. At this point, a quality charger or the BMS will stop the process.

Do LiFePO4 Batteries Need Float Charging?

The short answer: No, not in the traditional sense.

Unlike lead-acid batteries that require a constant "float" charge to stay full and prevent sulfation, LiFePO4 batteries have an extremely low self-discharge rate. Keeping them at a high voltage after they are full can stress the cells and reduce their long-term lifespan.

Correct "Float" Voltage Setting: For a 12V system, a setting of 13.5V to 13.8V is often labeled "float."
Its Real Purpose: In systems with a constant load (like an RV or solar setup), this setting doesn't charge the battery. Instead, it allows the charger/solar controller to power your electronics directly once the battery is full, preventing unnecessary draining and recharging cycles of your battery.

Equalization vs. Balancing: A Critical Distinction for LiFePO4

This is one of the most common and dangerous misconceptions. Traditional lead-acid "equalization" is a deliberate overcharge to de-sulfate plates, and this process is harmful to LiFePO4 cells.

What LiFePO4 batteries require is cell balancing.

What is Cell Balancing? A LiFePO4 battery is made of multiple cells in series (a 12V battery has 4 cells). Balancing ensures every cell is at the same voltage or state of charge. This is essential for health and capacity.
Who Handles It? Your battery’s internal Battery Management System (BMS) automatically handles the balancing, usually as the cells near a full charge. You do not need an external charger with an "Equalize" mode for this to happen.
Charger "Equalize" Setting: If a charger has an "Equalize" setting (often around 14.6V), it's simply holding the battery at the peak CV stage voltage. For a battery with a quality BMS, this is redundant.

Essential Safety Settings: LVC and the BMS

Your battery's BMS acts as its brain and protector. Two of its most important functions are managing low voltage and recovery.

Low Voltage Cutoff (LVC): The BMS will automatically disconnect the battery from the load to prevent over-discharging, which can cause permanent damage.
- Per Cell: ~2.5V
- For a 12V Battery: ~10.0V
Recovery Voltage: If the LVC is triggered, the BMS will keep the battery disconnected until it sees a charge from a compatible LiFePO4 charger. Once the voltage rises to a safe level, the BMS will "wake up" and allow the charge to continue normally.

Quick Reference: 12V LiFePO4 Charging Parameters

Parameter	Recommended Voltage/Setting	Purpose
Bulk / Absorption (CC/CV)	14.4V – 14.6V	The primary charging voltage where the battery reaches 100% state of charge.
Float	13.5V – 13.8V	(Optional) Powers system loads when the battery is full. Not for charging.
Equalization	Do Not Use.	Let the internal BMS manage cell balancing automatically.
Low Voltage Cutoff	~10.0V	Protective disconnect to prevent cell damage from over-discharge.

3.2 Discharging LiFePO4 Batteries:

A. Discharge Voltage Range:

LiFePO4 batteries can safely discharge down to 2.5V per cell, but most BMS systems will cut off at around 2.8V to 3.0V per cell to protect the battery. For a 12V battery, this is about 10V to 11V.

B. Depth of Discharge (DoD):

LiFePO4 batteries can be discharged up to 100% of their capacity without significantly reducing their lifespan. They support deep discharge without damage.

State of Charge (%)	Voltage (V)
100%	3.60-3.65
90%	3.50-3.55
80%	3.45-3.50
70%	3.40-3.45
60%	3.35-3.40
50%	3.30-3.35
40%	3.25-3.30
30%	3.20-3.25
20%	3.10-3.20
10%	2.90-3.00
0%	2.00-2.50

C. Temperature Range for Discharge:

The discharge temperature range is broader than the charging range, typically from -20°C to 60°C (-4°F to 140°F).

D. Discharge Rate:

These batteries have high discharge rates compared to lead-acid. LiFePO4 can safely discharge at high current, making them suitable for applications that require rapid power draw, such as electric motors.

E. Battery Management System (BMS):

LiFePO4 batteries usually come with an integrated BMS to monitor overcharging, over-discharging, overheating, and short circuits, ensuring safe operation.

information of battery management system protection

Part 4: How Does Voltage Affect LiFePO4 Battery Performance?

Voltage plays a crucial role in the performance, efficiency, and longevity of lithium iron phosphate (LiFePO4) batteries. Understanding how voltage impacts these factors is essential for optimal utilization and maintenance.

1. Capacity: The voltage of a LiFePO4 battery directly affects its capacity. As the voltage increases, so does the capacity, allowing the battery to store more energy and power your devices for longer periods. Higher voltage batteries are capable of handling larger energy demands.

2. Power Output: Voltage also influences the power output of the battery. Higher voltage batteries can deliver more power, which is important for applications that require high power output, such as electric vehicles and power tools. However, LiFePO4 batteries have lower voltage compared to other lithium-ion chemistries, so they may require more cells in series to achieve the desired voltage levels for certain applications.

3. Charging & Discharging: The voltage of a LiFePO4 battery influences its charging process. Charging the battery within the correct voltage range ensures safety and efficiency. Using an incorrect voltage can lead to overheating or undercharging, both of which negatively impact battery health, performance, and overall lifespan. Discharging below the recommended voltage level can cause permanent damage to the battery and reduce its lifespan. It’s important to avoid deep discharges to maintain optimal performance.

4. Safety and Stability: The voltage of a LiFePO4 battery contributes to its safety and stability. LiFePO4 batteries are known for their excellent thermal and chemical stability, and their lower operating voltage contributes to their overall safety. The lower voltage reduces the risk of thermal runaway and other safety issues associated with higher voltage lithium-ion chemistries.

All in all, voltage plays a critical role in determining the performance characteristics of LiFePO4 batteries, impacting their capacity, energy density, power output, charging characteristics, and safety. Understanding how voltage affects LiFePO4 batteries is important for designing and optimizing systems that use these batteries, such as electric vehicles, renewable energy storage systems, and portable electronics.

Part 5: How to Measure Battery Voltage

1. Utilizing a Votimeter

Measuring battery voltage typically involves using a voltmeter or a multimeter, a device specifically designed to determine the electrical potential difference between two points in an electrical circuit. Here's a general guide on how to measure battery voltage:

Select the Appropriate Voltmeter: Ensure that the voltmeter you use is capable of measuring the battery's voltage. It should have a voltage range that encompasses the expected voltage of the battery.
Turn Off the Circuit: If the battery is part of a larger circuit, switch off the circuit before measuring the battery voltage. This action helps prevent potential electrical hazards and ensures accurate measurements.
Connect the Voltmeter: Attach the voltmeter to the battery terminals. Typically, the red lead of the voltmeter connects to the positive terminal of the battery, while the black lead connects to the negative terminal.
Read the Voltage: Once the voltmeter is correctly connected, it will display the battery's voltage. If the voltmeter offers multiple voltage ranges, make sure it is set to an appropriate range for the expected battery voltage.
Interpret the Reading: The voltmeter will show the voltage in volts (V). Take note of the displayed reading to determine the battery's voltage.

Check Battery Voltage Using a Multimeter

It's important to note that when measuring battery voltage, especially in the case of rechargeable batteries, the voltage may vary based on whether the battery is fully charged, partially charged, or discharged. Therefore, it's crucial to consider the battery's state of charge when interpreting the voltage reading.

Furthermore, always adhere to safety precautions when working with batteries and electrical circuits to prevent injury or equipment damage.

2. Measuring Battery Voltage with a Battery Monitor

A battery monitor is a device permanently installed in your system to provide real-time data about your battery’s performance, including voltage, current, and charge status.

use battery monitor to check voltage

3. Measuring Battery Voltage via Bluetooth with a Smartphone

Many modern LiFePO4 batteries come with built-in Bluetooth functionality. This allows you to monitor the battery’s voltage and other data wirelessly via a smartphone app.

Part 6: How to Extend the Lifespan of a LiFePO4 Battery

1. Maintain Optimal Charge Levels

Avoid both deep discharging and overcharging your LiFePO₄ battery. Keeping the charge between 20% and 90% significantly reduces stress on the cells and enhances overall cycle life. Utilizing a Battery Management System (BMS) ensures proper voltage regulation, protecting against deep discharge and overvoltage.

2. Use Appropriate Charging Parameters

Charging at the correct voltage and current is essential for battery longevity. LiFePO₄ batteries typically require a constant current/constant voltage (CC/CV) charging method. The ideal charging voltage per cell is between 3.6V and 3.65V, with a recommended charge rate of 0.5C to 1C to prevent overheating and degradation.

3. Avoid Extreme Temperatures

High temperatures can accelerate cell degradation, while low temperatures may hinder charging efficiency. LiFePO₄ batteries perform best within the range of -20℃ to 60℃ (-4℉ to 140℉) during use and-10℃ to 50℃ (14℉ to 122℉) during storage. Operating and storing batteries within these temperature limits ensures optimal performance and longevity.

4. Store Batteries Correctly

When storing a LiFePO₄ battery for an extended period, keep it at a 50% charge in a cool, dry location to minimize self-discharge and internal resistance buildup. Avoid high-humidity environments to prevent corrosion or damage to the battery terminals.

5. Implement a Compatible Battery Management System (BMS)

A BMS safeguards against voltage spikes, overcurrent, and thermal runaway, all of which can reduce battery lifespan. Ensure your LiFePO₄ system includes a BMS to balance individual cells, manage temperature, and protect against unsafe charging and discharging conditions.

LiFePO4 Voltage: Frequently Asked Questions (2025 Edition)

What is the voltage of a single LiFePO4 cell?

A single LiFePO4 cell has a nominal voltage of 3.2V. Its safe operating window is typically between 2.5V (fully discharged) and 3.65V (fully charged). It is critical that the cell voltage does not drop below 2.5V to avoid permanent damage.

What is the nominal voltage of lithium batteries?

Lithium batteries generally have a nominal voltage of approximately 3.7V per cell. When fully charged, a 12V LiFePO4 battery can reach about 13.3V to 13.4V.

What is the voltage range of a LiFePO4 cell?

The nominal voltage of a LiFePO4 cell is 3.2V. These cells are considered fully discharged at 2.5V and fully charged at 3.65V. Note that these values may vary based on the specific cell specifications.

What is the minimum voltage that can damage a LiFePO4 battery?

The minimum voltage threshold for 12V LiFePO4 batteries is around 10V. Discharging the battery below this voltage can lead to permanent damage. Regularly monitoring the voltage chart is essential for safe charging.

What is the low voltage cutoff for LiFePO4 batteries?

The low voltage cutoff for LiFePO4 batteries is typically set at 2.5V per cell, which is the voltage below which the battery should not discharge to prevent damage.

What voltage should be used for bulk charging of LiFePO4?

The bulk/absorb voltage for LiFePO4 batteries usually falls between 14.2V and 14.6V. A voltage of 14.0V may also be acceptable with sufficient absorb time. Slightly higher voltages, around 14.8V to 15.0V, can be used briefly before disconnecting the battery.

How can I tell if my LiFePO4 battery is going bad?

While LiFePO4 batteries have a very long life, they will eventually degrade. Here are three common signs that your battery may be failing:

Reduced Capacity: The battery doesn't hold a charge for as long as it used to.
Charging Problems: It takes much longer than usual to charge, or it fails to reach a full 100% charge.
Physical Swelling: The battery case looks puffy or swollen. This indicates an internal failure, and the battery should be safely decommissioned immediately.

Conclusion

Understanding the voltage characteristics of LiFePO4 lithium batteries is essential for their effective utilization in a wide range of applications. By referencing a LiFePO4 lithium battery voltage chart, you can make informed decisions regarding charging, discharging, and overall battery management, ultimately maximizing the performance and lifespan of these advanced energy storage solutions.

For more information on LiFePO4 lithium batteries and their voltage characteristics, consult with reputable manufacturers like LiTime and industry experts to ensure the successful integration of these advanced energy storage solutions into your projects.

Join LiTime Membership to Unlock Exclusive Benefits

Login to LiTime

Create a LiTime Account

Forgot your Password?

Change your password.

Reset Your Password

Verify your email address.

We have sent you an email

Set Your Password