Ultimate Guide to LiFePO4 Voltage Chart

Knowledge ·November 14, 2023

Ultimate Guide to LiFePO4 Voltage Chart

Over the past couple of years, LiFePO4 (Lithium iron phosphate) batteries have become a popular choice to charge appliances. These types of batteries are used in solar generators due to their long lifecycle, improved safety features, high energy density, and more.

Understanding how to read the LiFePO4 voltage chart lets you monitor the battery's performance and ensure safe operation.

One popular battery backup for off-grid living is Jackery Explorer 2000 Plus. It has an expandable LiFePO4 battery that seamlessly charges 99% of home appliances. With the help of Jackery Battery Pack 2000 Plus, you can expand the capacity from 2kWh to 24kWh.

Jackery Explorer 2000 Plus Portable Power Station

- Easy to expand from 2kWh to 24kWh.

- Long-lasting battery life of up to 4000 charge cycles.

- Whisper-quiet and fumes-free operation.

- Built to power 99% of home or outdoor appliances.

- Produce less than 30dB of noise.

What is LiFePO4 Battery Voltage

LiFePO4 is one of the most popular and safest batteries integrated into solar systems. They have an extremely long lifecycle and require little to no maintenance.

The LiFePO4 battery's voltage generally depends on its state of charge. However, the LiFePO4 voltage chart is non-linear, which means a slight change in SoC can lead to a significant voltage change.

What is LiFePO4 Voltage Chart

The lithium iron phosphate (LiFePO4) battery voltage chart represents the state of charge (usually in percentage) of 1 cell based on different voltages, like 12V, 24V, and 48V.

Percentage (SOC)

1 Cell

12V

24V

48V

100% Charging

3.65

14.6

29.2

58.4

100% Rest

3.40

13.6

27.2

54.4

90%

3.35

13.4

26.8

53.1

80%

3.32

13.3

26.6

53.1

70%

3.30

13.2

26.4

52.8

60%

3.27

13.1

26.1

52.3

50%

3.26

13.0

26.1

52.2

40%

3.25

13.0

26.0

52.0

30%

3.22

12.9

25.8

51.5

20%

3.20

12.8

25.6

51.2

10%

3.00

12.0

24.0

48.0

2.50

10.0

20.0

40.0

Individual LiFePO4 cells typically have a 3.2V nominal voltage. The cells are fully charged at 3.65V, and at 2.5V, it becomes fully discharged.

3.2v_lifepo4_cell_voltage_chart_1024x1024

12V 100Ah LiFePO4 batteries are a great upgrade for 12V lead acid batteries. They are one of the safest batteries for off-grid solar systems. When they are fully charged, the battery voltage becomes 14.6V. It drops to 10 volts when fully discharged. The below 12V LiFePO4 battery voltage chart reveals how the voltage drops concerning battery capacity.

12VLIF_1_81223301-00bc-4d72-9923-4ea3c174c108_1024x1024

You can either purchase a 24V LiFePO4 battery or buy two identical 12V LiFePO4 batteries and connect them in series. These batteries are fully charged at 29.2V and drop to 20 volts when discharging.

48V batteries are generally used in larger solar power systems. The high-voltage solar system keeps the amperage low, helping you save high on equipment and wiring costs.

LiFePO4 Battery Charging & Discharging

A battery's SoC (state of charge) indicates the remaining capacity that can be discharged over the battery pack's total capacity. Suppose you have a battery pack rated 100Ah and still have 30Ah left to discharge. In this case, the SoC will be 30%.

In other words, if you charge the battery to 100Ah and then discharge around 70Ah, it will still have 30Ah left. The SoC of a battery depends on its voltage and vice versa. When the battery is charged, the voltage increases.

SOC (100%)

Voltage (V)

100

3.60-3.65

3.50-3.55

3.60-3.50

3.40-3.45

3.35-3.40

3.30-3.35

3.25-3.30

3.20-3.25

3.10-3.20

2.90-3.00

2.00-2.50

State of the Charge Curve

The state of the charge curve indicates how the 1-cell battery voltage varies depending on charging time.

LiFePO4 Battery Charging Parameters

Some basic LiFePO4 battery charging parameters include different types of voltages, such as charging, float, maximum/minimum, and nominal. The below table reveals the battery charging parameters at 3.2V, 12V, 24V, and 48V.

Characteristics

3.2V

12V

24V

48V

Charging Voltage

3.5~3.65V

14.2~14.6V

28.4V~29.2V

56.8V~58.4V

Float Voltage

3.2V

13.6V

27.2V

54.4V

Maximum Voltage

3.65V

14.6V

29.2V

58.4V

Minimum Voltage

2.5V

10V

20V

40V

Nominal Voltage

3.2V

12V/12.8V

24V/25.6V

Float, Bulk, and Equalize Voltage of LiFePO4

One important thing to note is that lithium only supports bulk charging. Once the LiFePO4 battery is fully charged, it shuts off.

The three most common types of voltages include bulk, float, and equalize.

Bulk Voltage: This is the voltage at which the battery is charged faster. It usually occurs during the initial stage of charging, when the battery is completely discharged. The bulk voltage of a 12-volt LiFePO4 battery is 14.6V.

Float Voltage: Generally lower than the bulk voltage, it is the maintained voltage once the battery is fully charged. The float voltage of a 12-volt LiFePO4 battery is 13.5V.

Equalize Voltage: Equalization is an important process that must be performed regularly to maintain the battery capacity. The 12-volt LiFePO4 battery's equalized voltage is 14.6V.

Types

3.2V

12V

24V

48V

Bulk

3.65V

14.6V

29.2V

58.4V

Float

3.375V

13.5V

27.0V

54.0V

Equalize

3.65V

14.6V

29.2V

58.4V

Battery Discharge Curve

Discharge means the power is withdrawn from the battery to charge appliances. The battery discharge chart typically represents the relationship between voltage and discharge time.

Below is the 12V LiFePO4 discharge curve at different discharge rates.

How to Check LiFePO4 Battery Capacity

Checking the LiFePO4 battery capacity is one of the best ways to keep it safe and enhance its lifespan. Below are the three simple methods to measure the capacity and ensure it is not fully discharged.

Method 1: Check via Multimeter

Checking the open circuit battery voltage via a multimeter method is moderately accurate. However, there is one downside. You'll have to disconnect all loads and chargers and keep the battery at rest.

First, you must remove the loads and chargers attached to the LiFePO4 battery. Wait 15-30 minutes before measuring the open circuit voltage using the multimeter. You can compare it with the SoC chart in your battery manual or the voltage curve chart.

Method 2: Use a Battery Monitor

This is one of the most accessible and reliable methods to measure battery capacity. All you need to do is connect a high-quality battery monitor to the battery and determine the charge level.

Method 3: Use a Solar Charge Controller

Using the solar charge controller to determine the battery capacity may seem convenient, but it is not a very accurate method. The voltage reading is mainly inaccurate as the measurement is done with loads and chargers attached.

Jackery LiFePO4 Portable Power Station

Jackery is the pioneer in manufacturing superior-quality solar products, including solar panels, solar generators, and power stations. Whether you're living off-grid, camping, or want a backup solution for your home, Jackery Explorer Portable Power Stations has your back.

Jackery Explorer 1000 Pro Portable Power Station

Jackery Explorer 2000 Plus

View Jackery Explorer 2000 Plus Portable Power Station👉

The power stations manufactured by Jackery feature lithium-ion and LiFePO4 batteries, known for their durable and long-lasting nature. Jackery Explorer 2000 Plus Power Station delivers a mega 2kWh to 24kWh power. It has an expandable LiFePO4 battery that can be increased or decreased by adding battery packs.

You can recharge the Explorer 2000 Plus using 6*Jackery SolarSaga 100W Solar Panels in only 6 hours. These solar panels are highly efficient, with a solar conversion efficiency of 25%.

LiFePO4 Voltage Chart FAQs

1. What effects of voltage will influence the LiFePO4 battery performance?

Voltage affects the LiFePO4 performance by altering the power it delivers, the energy it stores, and the overall lifespan.

Capacity: Battery voltage and capacity are directly proportional to each other. This means the voltage increase can increase the battery capacity.

Charging: The low charging voltage can reduce the battery capacity. On the other hand, the high charging voltage can lead to overcharging and damage.

Discharged: When the LiFePO4 battery is discharged below its recommended level, it reduces its capacity and lifespan.

Efficiency: A battery with higher voltage is generally more efficient in supplying more power to the appliances.

2. How to increase the LiFePO4 battery lifespan?

One of the simple methods to boost the lifespan or charging/discharging rates is by increasing the battery's Ah capacity. The nylon tape around the cells and keeping the battery at a cool temperature can also improve the lifespan.

Voltage

Capacity

Charge Cycles

Lifespan (Above 80% Original Capacity)

(V)

(Ah %)

(If charged and discharged to each of these voltages every day)

(Charged once a day)

14.4V

100%

3200 cycles

9 years

13.6V

100%

3200 cycles

9 years

13.4V

99%

3200 cycles

9 years

13.3V

90%

4500 cycles

12.5 years

13.2V

70%

8000 cycles

20 years

13.1V

40%

8000 cycles

20 years

13.0V

30%

8000 cycles

20 years

12.9V

20%

8000 cycles

20 years

12.8V

17%

6000 cycles

16.5 years

12.5V

14%

4500 cycles

12.5 years

12.0V

4500 cycles

12.5 years

10.0V

3200 cycles

9 years

3. What is the minimum voltage damage for LiFePO4?

The minimum voltage damage for 12V LiFePO4 batteries is around 10V. If the LiFePO4 battery is discharged below the minimum voltage, it will likely be permanently damaged. That's why it's vital to check the LiFePO4 battery voltage chart and ensure you safely charge your batteries.

Final Thoughts

Even though LiFePO4 batteries are not the least expensive or budget-friendly, they are the most cost effective in the long run. You can quickly check the battery's SoC using the LiFePO4 voltage chart.

Jackery Explorer 2000 Plus Power Stations are built with a high-quality LiFePO4 battery. It has a battery capacity of 2042.8Wh, which ensures a reliable power supply. You can charge most of your home or outdoor appliances using the solar generator.