LiFePO4 Voltage Chart: 3.2V, 12V, 24V, 36V & 48V Battery Guide
- Key Takeaways
- LiFePO4 Voltage Chart by State of Charge
- Why LiFePO4 Voltage Does Not Change Evenly With State of Charge
- How LiFePO4 Pack Voltage Is Built From 3.2V Cells
- What Is the Correct LiFePO4 Charging Voltage?
- How to Read a LiFePO4 Battery Voltage Correctly
- What Can Affect LiFePO4 Voltage Readings?
- LiFePO4 vs NMC Lithium-Ion Voltage Chart
- EcoFlow Portable Power Stations Using LiFePO4 Batteries
- Conclusion
- FAQs
A LiFePO4 voltage chart helps you estimate battery charge by comparing a resting voltage reading with a reference table. Common 12V, 24V, 36V and 48V packs have nominal voltages of 12.8V, 25.6V, 38.4V and 51.2V, respectively. This guide explains the chart, charging voltages and measurement methods so you can interpret readings from a caravan battery, solar storage system or portable power station.
Key Takeaways
A LiFePO4 battery voltage chart gives an approximate charge reference from a rested reading.
Common 4S, 8S, 12S and 16S packs are nominally 12.8V, 25.6V, 38.4V and 51.2V.
Resting voltage, charging endpoints and protection cut-offs describe different conditions.
Use a LiFePO4 charging profile matched to the battery and its operating limits.
A calibrated monitor or power station display helps you track charge during everyday use.
LiFePO4 Voltage Chart by State of Charge
A lithium battery state of charge chart compares settled resting voltage with an approximate charge level. The lithium battery voltage chart below covers single cells and common 4S, 8S, 12S and 16S LiFePO4 packs. Pack values are illustrative references calculated from the single-cell voltage multiplied by the series cell count. Take readings after charging and connected loads have stopped; use a calibrated monitor to track charge through the flat middle range.
Approximate SOC | 3.2V Cell / 1S | 12V Class / 4S | 24V Class / 8S | 36V Class / 12S | 48V Class / 16S |
100% rested | 3.40V | 13.6V | 27.2V | 40.8V | 54.4V |
90% | 3.35V | 13.4V | 26.8V | 40.2V | 53.6V |
70% | 3.30V | 13.2V | 26.4V | 39.6V | 52.8V |
50% | 3.25V | 13.0V | 26.0V | 39.0V | 52.0V |
30% | 3.20V | 12.8V | 25.6V | 38.4V | 51.2V |
10% | 3.00V | 12.0V | 24.0V | 36.0V | 48.0V |
Why LiFePO4 Voltage Does Not Change Evenly With State of Charge
Inside a LiFePO4 cell, lithium moves between the electrodes as the battery charges and discharges. Much of that transfer occurs across a relatively flat voltage plateau. You can therefore use a substantial part of the stored energy while seeing only a small voltage change. This is why a steady reading in a caravan or ute battery does not mean its charge level has stayed the same.
An LFP fuel-gauging application note explains why charge estimation needs to account for the chemistry’s flat voltage curve and hysteresis. A calibrated monitor combines current tracking with battery-specific information. Use voltage to identify broad charge conditions, and the monitor to follow how much energy you have used.
How LiFePO4 Pack Voltage Is Built From 3.2V Cells
Series connections add cell voltages. Four 3.2V cells give 12.8V nominal; eight give 25.6V; twelve give 38.4V; sixteen give 51.2V. The twelve-cell arrangement, written as 12S, is commonly labelled 36V and is used in applications such as compatible electric golf carts and trolling-motor systems. Connecting identical cells in series keeps the same amp-hour rating while increasing stored watt-hours. For example, a 100Ah pack stores approximately 1,280Wh at 12.8V or 2,560Wh at 25.6V.
12V LiFePO4 Battery
A 12V-class LiFePO4 battery normally uses four cells in series, written as 4S. Its nominal voltage is 12.8V, even though the system is called 12V. Use the 12V LiFePO4 voltage chart column for this configuration. The example shows about 13.6V near full resting charge and 13.0V around half charge. Caravans, 4WDs and boats commonly use this battery class.
24V LiFePO4 Battery
Eight cells in series form a 25.6V nominal pack, commonly labelled 24V. At the same power, a higher system voltage requires less current, helping reduce cable losses. When reading a LiFePO4 voltage chart for 24V systems, choose the 8S column. Its example half-charge reference is 26.0V; its nominal 25.6V rating is a different reference, not a fixed SOC reading.
48V LiFePO4 Battery
A 48V-class LiFePO4 solar battery commonly uses sixteen cells for a 51.2V nominal. The LiFePO4 voltage chart for 48V packs above follows that 16S arrangement, with about 52.0V as its half-charge example. Identify the cell count before choosing a column: a 15S pack is nominally 48.0V and needs its own charging settings and voltage references.
What Is the Correct LiFePO4 Charging Voltage?
LiFePO4 charging uses a controlled current followed by a voltage-limited stage as the battery fills. The lithium battery charge voltage is higher than the settled reading you use for a SOC estimate. A LiFePO4 charging voltage chart should therefore be read as a reference for the charging process. Common charging-voltage ranges for the configurations discussed here are:
12V class / 4S: 14.2–14.6V
24V class / 8S: 28.4–29.2V
36V class / 12S: 42.6–43.8V
48V class / 16S: 56.8–58.4V
Use the battery manufacturer’s specified charge voltage, current limit and temperature range to configure the charger. LiFePO4 does not need traditional lead-acid float charging, although some approved charging profiles use a lower maintenance voltage after charging. The BMS provides protection; its cut-off is not a target for routine discharge. For example, 2.5V per cell is a lower limit used in some specifications, not a universal empty resting reading.
How to Read a LiFePO4 Battery Voltage Correctly
For a separate battery with accessible terminals, stop charging and switch off connected loads, then let the battery rest for the period specified in its manual. Measure directly across the terminals with a suitable DC voltmeter and compare the stable reading with the correct cell-count column. For a sealed portable power station, use its display or app: a regulated output socket does not reveal the internal battery voltage. The table compares the main methods for assessing charge and diagnosing voltage changes.
Method | Strength | Limitation | Best Use |
Resting Voltage (Multimeter) | Simple, low-cost measurement | Requires rest; poor accuracy across mid-range charge levels | Checking near-full or near-empty batteries |
Voltage Under Load | Helps identify voltage drops across cables and terminals | Voltage sag makes charge estimates unreliable | Fault-finding in electrical systems |
Shunt Battery Monitor | Tracks current flow and estimates remaining capacity | Requires installation, calibration and periodic synchronisation | Caravans and off-grid battery systems |
BMS or App Percentage | Convenient charge estimates without separate monitoring equipment | Accuracy depends on the BMS estimation method and calibration | Portable power stations and smart batteries |
What Can Affect LiFePO4 Voltage Readings?
Before treating a change as lost capacity, identify how the reading was taken. The same battery can show different terminal voltages while charging, resting and powering an appliance. These factors explain the differences:
Temperature: Cold increases internal resistance, so a battery can show a larger voltage drop while supplying the same load.
Charging and load: A charger raises the terminal voltage; an appliance draws it down. Compare readings taken in the same operating state.
Cell balance and BMS behaviour: Total pack voltage can hide one low cell. That cell can trigger protection while the combined reading still looks reasonable.
Battery age: Ageing reduces usable capacity and can increase resistance. A familiar resting voltage does not prove that the original capacity remains.
Wiring and measurement: Loose terminals, long cables and meter accuracy affect the reading. Measure at the battery terminals to separate battery voltage from wiring losses.
LiFePO4 vs NMC Lithium-Ion Voltage Chart
Lithium battery cell voltage depends on chemistry. LiFePO4 is a type of lithium-ion battery, but its nominal voltage and charging profile differ from NMC. A lithium voltage chart labelled only by pack voltage can hide that distinction. Identify both the chemistry and series cell count before selecting a reference.
The table compares common cell-level references. The full-charge figures describe typical charging endpoints for the specified chemistry, rather than rested SOC readings.
Chemistry | Nominal Cell Voltage | Typical Full-Charge Cell Voltage | Voltage Curve | Common Uses |
LiFePO4 (LFP) | 3.2V | 3.65V | Flat across most charge levels | Portable power stations, home batteries, caravans and EVs |
NMC Lithium-Ion | 3.6V–3.7V | 4.2V | Gradual decline during discharge | EVs, e-bikes and power tools |
The cell-count difference matters when choosing a charger. Four LiFePO4 cells can reach 14.6V at a permitted charging endpoint, while three conventional 4.2V NMC cells reach 12.6V and four reach 16.8V. A lithium battery charging chart must match the chemistry and pack construction. Similar pack labels do not make their charging profiles interchangeable.
EcoFlow Portable Power Stations Using LiFePO4 Batteries
A portable power station combines the battery, charge management, and appliance outputs into a single unit. Its display and app let you follow the estimated charge and power flow without measuring internal cells. Choose a setup based on the devices you use, the energy they consume, and the time between recharges.
EcoFlow RIVER 3 Plus Portable Power Station
For a home desk setup with a lamp, phone and laptop, the EcoFlow RIVER 3 Plus Portable Power Station provides a compact power source beside your workspace. Its built-in UPS function switches to battery power when mains power fails, helping keep connected equipment running. Efficient operation with small loads extends use between recharges, while the battery display makes it easy to see when to top up. The LFP battery supports repeated charging for everyday use.
EcoFlow DELTA 3 Plus Portable Power Station
For home backup covering a fridge, network equipment and a desktop computer, the EcoFlow DELTA 3 Plus Portable Power Station combines charge monitoring with UPS functionality that helps keep connected equipment running when mains power fails. App controls let you manage charging and reserve levels, while compatible extra batteries let you expand storage as your backup needs change.
Conclusion
Use a LiFePO4 voltage chart to interpret a stable reading, starting with the battery’s chemistry and cell count. Keep nominal voltage, resting SOC and charging settings separate. For everyday energy planning, follow a calibrated charge monitor or the power station’s display and app, then recharge around the devices you need to keep running.
FAQs
What Voltage Is a Fully Charged 12V LiFePO4 Battery?
A four-cell, 12V-class LiFePO4 battery commonly reaches 14.2–14.6V during the final charging stage. After charging stops and the battery rests, this article’s example places a full reading around 13.6V. The drop is normal voltage relaxation. Use the pack’s specified charging endpoint when setting a charger; the resting reference serves a different purpose.
What Voltage Is 50% State of Charge for LiFePO4?
This chart uses about 13.0V as the half-charge reference for a four-cell, 12V-class pack. The corresponding examples are 3.25V per cell, 26.0V for eight cells, 39.0V for twelve and 52.0V for sixteen. Treat these as broad reference points. A stable mid-range voltage cannot establish an exact 50% reading; use calibrated charge tracking when planning remaining runtime.
Can You Use Voltage Alone to Measure LiFePO4 State of Charge?
Use voltage for a rough charge check, then use a calibrated monitor for everyday SOC tracking. A shunt monitor counts current entering and leaving the battery, so it can follow energy use through LiFePO4’s flat voltage range. Enter the correct battery capacity and synchronise the monitor as instructed. On a portable power station, use the built-in display or app.
Why Does My LiFePO4 Voltage Drop Under Load?
Current passing through the battery’s internal resistance lowers its terminal voltage under load. Cables and connections add further voltage drop between the battery and the appliance. Compare readings at both points while the same load is running to identify wiring losses. Voltage normally recovers after the load stops; a sudden or excessive drop calls for checking connections and battery condition.
Can I Use a Lead-Acid Charger for a LiFePO4 Battery?
Use a charger with a LiFePO4 mode approved for your battery. An existing lead-acid charger is suitable only if its complete charging profile meets the pack’s requirements, including voltage, current and behaviour after full charge. Disable desulphation or equalisation modes unless the battery maker explicitly permits them. A matching nominal voltage alone does not establish charger compatibility.