This article will show you the LiFePO4 voltage and SOC chart.
This is the complete voltage chart for LiFePO4 batteries, from the individual cell to 12V, 24V, and 48V.
Battery Voltage Chart for LiFePO4
Download the LiFePO4 voltage chart here (right-click -> save image as).
Manufacturers are required to ship the batteries at a 30% state of charge. This is to limit the stored energy during transportation. It is also a good state of charge for the battery to sit at. This is because they have a low self-discharge rate (less than 3% per month).
So when you receive a 12v lifepo4 battery, it will be around 13 volts.
You need to know that the discharge rate affects the voltage. If we discharge a battery at 1C, the voltage will be lower than at 0.2C. That’s why you should measure the voltage in an open circuit or with no loads attached.
Bulk, Float, and Equalize Voltages of LiFePO4
Some charge controllers do not have dedicated Lithium charging parameters. Therefore, you must adjust the lead-acid parameters to match the lithium characteristics. It’s important to know that lithium only has bulk charging. It charges as much as possible, and when the battery is full, it stops.
The Bulk charge will be set at 100% SOC. The battery will be charged until this voltage is reached.
The float function for lead-acid batteries keeps the batteries topped up at a specific voltage. Lithium has a very low self-discharge rate, so we can set it at 50% capacity. Because that’s the point where a LiFePO4 battery is stable, you can also set it at 80-90% SOC. If you can disable it, do that.
The equalize function is also something for lead acid. If you can disable it, do that, but if you cannot, use the recommended voltages in the table below.
| 3.6V | 12V | 24V | 48V | |
| Bulk/Absorb | 3.55-3.65 | 14.2-14.6 | 28.4-29.2 | 56.8-58.4 |
| Float | 3.375 | 13.5 | 27.0 | 54.0 |
| Equalize | 3.65 | 14.6 | 29.2 | 58.4 |
Bulk/absorb voltage is a range. Choose a lower range for a longer battery lifespan. Choose a higher range for more capacity. Bulk voltage is your charging voltage.
Absorption time is not applicable for LiFePO4. If you have to set an absorption time, set it to 2 hours (source).
Understanding LiFePO4 Battery Voltage
LiFePO4 batteries, known for their stability and safety, have unique voltage characteristics that set them apart from other types like lead-acid batteries.
- LiFePO4 batteries exhibit a very flat voltage curve during discharge. This means the voltage remains relatively constant for most of the discharge cycle, providing a stable power output.
- The flat curve also makes it challenging to determine the exact state of charge (SOC) based solely on voltage. This is why additional tools like battery monitors are often necessary for accurate SOC readings.
Best Way to Check LiFePO4 Battery Capacity
The best way to check the remaining battery capacity of a LiFePO4 battery is to use a battery monitor. A battery monitor is a device that calculates the remaining capacity of the battery using a shunt. The shunt is an additional part you need to purchase. Read my guide on the best battery monitors here.
FAQ
What voltage should a LiFePO4 battery be?
Between 12.0V and 13.6V for a 12V battery.
Between 24.0V and 27.2V for a 24V battery.
Between 48.0V and 54.4V for a 48V battery.
What voltage is too low for a lithium battery?
For a 12V battery, a voltage under 12V is considered too low.
For a 24V battery, voltages under 24V are considered too low.
For a 48V battery, voltages under 48V are considered too low.
If the voltage goes below these values, it can damage the battery in the long term. The minimum voltage of a cell should be 3V (10%) or 3.2V (20%).
What is the low voltage cutoff for 12V LiFePO4?
The cutoff for a 12V battery is 10V. However, I recommend setting it to 12V, which equals 10%. This will improve the battery lifespan. 12V divided by 4 lifepo4 cells is 3V per cel. To increase battery lifespan even further, you can set it to 3.2V, which is 20% or 12.8V.
What is the low voltage cutoff for 24V LiFePO4?
The cutoff for a 24V battery is 20V. However, I recommend setting it to 24V, which equals 10%. This will improve the battery lifespan.
What is the low voltage cutoff for 48V LiFePO4?
The cutoff for a 48V battery is 40V. However, I recommend setting it to 48V, which equals 10%. This will improve the battery lifespan.
What is the best float voltage for 12V LiFePO4?
The best float voltage for a 12V lithium battery is 13.5V.
What is the best float voltage for 24V LiFePO4?
The best float voltage for a 24V lithium battery is 27V.
What is the best float voltage for 48V LiFePO4?
The best float voltage for a 48V lithium battery is 54V.
What is the acceptable cell voltage difference for LiFePO4?
The acceptable cell voltage difference for LiFePO4 is 0.1V. You will only reach this level when the battery is either fully charged or fully discharged. This is because a LiFePO4 voltage curve is flat in the middle.
What is the voltage level of a lead-acid battery?
Read my guide about the voltages for lead-acid batteries.
Sources:
I’m an off-grid enthusiast. I created this website to give clear and straight-to-the-point advice about solar power. I’m also the author of the book ‘Off-grid solar power simplified‘. Read more about me on my about page, check out my Youtube channel, or send me a message.
I got a 100ah LiFePo4, put a LiFePo4 charger putting out 1.5 amps, meter shows 13.6 max while charging, but when it said FULL I disconnected charger clamp and volt meter display showed 12.8VDC but jumped all over the place, up to 13.2VDC so is this brand new battery screwy?
It will take a long time to charge a battery with a 1.5A charger. Are you sure you put the right parameters in the charger? Did the charger stop charging when it reached 13.6V?
What is the c rating for 900ah lifepo4 batteries 3 300ah batteries in parallel
Hello Mike,
Parallel = Capacity gets added up.
So, 0.5C with a 900Ah battery will be 450A.
I have a KS Energy 205 AHr 12V LiFePO4 battery. It has bluetooth monitoring and according to the app it is at 90% SOC but the voltage is only 11.87V with no load. The individual cells are 2968, 2970, 2970 and 2970 mV. Temperature 8 deg C. Any idea why the voltage is so low?
Your battery looks to be empty. Is it possible to charge it without the BMS shutting it down at 100%. If that’s not possible you need to look into recalibrating the SOC. Normally, this can be done through the app of the BMS. It could also be in storage mode, refer to the manual how to take it out of storage mode.
If you have small loads the BMS SOC cant be calculated (the BMS dont have a real shunt, it only use a hall sensor) , you need a real shunt for that. ex. Victron Smart Shunt.
Hey Nick,
do you know which temperature is the lowest but not unhealthy for LiFePo4 loading? Ive heard about 5°C, are -1°C also possible and save?
thanks for answer 🙂
On the datasheet from EVE cells, we can see: Charging 0°C ~ 55°C, Discharging -20°C ~ 55°C.
Capacity and max cycle count are typically granted for “room temperature”, or, +25°C. I try to keep my batteries above 10°C by drivinǵ the solar charge to warming elements until the batt reaches +10°C. Cooling starts at +40°C and release at +35°C.
Hey Nick
in your article above there is a fault number in the tabe above the line “Increase the lifespan of your LifePO4 battery Cycle life”
in line 3 float the correct number at 48 V column should be 52,0 (V) , not 42.0V.
You are right Bert. Thanks for spotting!
Nick, just read your article on “LiFePO4 voltage charts” and noticed your low cutoff voltage for 12V 24V and 48v were all 12V. Probably just a typo in the 24V and 48V paragraphs.
Thank you Mason! I made the correction.
Hello Nick –
Please I have a 48v Magnum Inverter with output power of 4300VA. I just replaced my flooded batteries with LiFePO4 (48V , 300ah, Rated voltage 51.6v, charging current 50A). Please what will be the setpoints of my bulk, absorb and float voltage? what will also be my re-bulk voltage. Please assist if you can.
Check out the end of the article where I write down these values for your 48V battery.
Hi Nick, great article and I use your Voltage Chart all the time.
Regarding the above question, I have two 48v LifePo4 Battery 155AH.
I couldn’t see your suggested Bulk (Absorption) and Float settings other than the Equalising Voltages.
One problem I have with one Battery is that it charges to around 85% SOC and one Cell goes rogue to 3650mv, the Battery OV’s and SOC jumps to 100%.
Have you ever come across this before? with any solution?
It’s in there just above ‘Increase the lifespan of your LifePO4 battery’
I haven’t experienced this. You have individual cells right? Have you top or bottom balanced them?
Hi Nick. Is it necessary to both, top and bottom balance the batteries?
I’ve got 4 batteries connected in parallel. they often reach 100% charge, but generally never drop below 40%
Also, is there any significant benefit to charging the batteries at 0.3c, as opposed to 0.4c? they are rated at 1c
You don’t need to balance if there is no significant difference between the cells at 0 and 100%. If there is a significant difference, then do a top balance. If you don’t have a BMS, do a bottom balance. I have written articles about balancing here.
You dont need to balance if there is no significant difference in the cells at 0 and 100%. If you have a BMS and there is a significant difference, then do a top balance. If you don’t have a BMS do a bottom balance. More info on balancing here: Bottom Balancing LiFePO4 There is no significant difference between 0.4 and 0.3C. Don’t worry about that.
Great notes and soc chart Nick!
I just upgraded from an old 24v lead acid battery setup to a new 24v lithium one (one of the 12v batteries in the bank gave up!).
Didn’t know what settings to use on my solar charge controller, or what cut off voltage to use for my grid tied inverter, until I found your article.
It’s very different settings compared to lead acid, so thank you very much for taking your time to share this and for being so thorough as it has helped me decide on the settings that suit my setup!
Thanks for the kind words Ford.
Great website! Great book! Great detail! And…Nick is always available to answer questions. He responds to emails daily, you won’t wait long for personalized guidance. Thanks Nick.
Thanks Richard. I appreciate the comment.
Hello Nick –
My 48v lithium battery mostly does not go below 51v DoD due to constant utility power supply which does not allow it to go lower than above while in use. Please will this in any way affect my battery lifespan as it mostly don’t get discharged before another charge up.
Thanks for responding!
Hello Steve, It will increase the lifespan of your battery. Going to 51V will be around 20% which is great. As you can read in my article here. I also recommend charging up to 90% (not 100%). You can do this by adjusting the charging parameters in your charge controller to 53.6V.
Thank you so much Nick – I guess the 53.6v mentioned above should be the float setting right?
Float is only applicable to lead-acid batteries because they have a high self-discharge. If you can, you should disable it on lifepo4. If you cannot, then use 54V.
Hi nick I have a 120ah lifepo4 battery charging off a 200w solar blanket. The battery is reading 13.1v and in great sunlight the best charge I can get is approx 2.5a to the battery. I would expect 8 to 10 amps from the blanket. Is there something I am missing?
Cheers
Adam
Is the voltage 13.1V without loads and no charge applied?
What kind of charge controller do you have? Is it embedded in the solar blanket?
I have four 3.2v 100 AH Lifepo4 batteries. They’re 6 years old. One has swollen up after I mistakenly left all four on a 12v trickle charger. I assume the swollen one is no good; the others charge to 3.34 or 3.35. Can I buy a new battery and connect it in series with the three that are good?
The one that is overcharged will have a reduced capacity. Placing the overcharged battery in series to make a 12V battery will be bad because the whole pack will suffer from it. You would constantly need to balance the cells. Depending on the severity of the case, this would be an external active balancer. Weird that only one swole, I assume because it had a lower capacity to begin with (no matched cells). If you left all 4 on a trickle charger in series, then there shouldn’t be a case of overcharging right? If you charged them in parallel, meaning 13.6V per cel ,then that is a problem. The cells would be severely damaged and capacity is certainly lost.
thank you very much, but I’m a little unclear about your answer. Are you saying it would be best to buy a new 3.2v 100 ah lifepo4 battery and that I can use it with the older batteries in a 4s or 12s configuration?
Hi Nick thanks for this information. I have a 2 batteries of 5kw each and the label show operation voltage range 44.8v to 57.6v, considering it what value you recommend for bulk and floating voltage ?
Check the table in the middle of the article:
bulk: 56.8-58.4
float: 54.0
I recently got a 3kva system with a 24V 100Ah lithium battery and a 3kva 145VDC MPPT Hybrid Inverter then the problem of persistent decrease of battery capacity is continuing on the very first day when it was installed last full charge was 95% percent the next day after use was 94% right it was not in use and when it was in use it falls to 83% and when charging it won’t go back to the 95% where it was fully charged it keeps on reducing yesterday night after charging it was on 91% during the day it decreased to 90% and now it has charged but it’s now on 90% meaning it’s fully charged so due to noticing it’s circle by tomorrow morning it will be on 89% meaning after use and back to fully charged it will remain on 89% it won’t go back to 95% where it could fully charged the day it was installed the holding capacity is continuing to decrease daily what could be the problem
If the hybrid inverter is on all the time, then it will consume power. It can draw 50W depending on the brand. So 50W*24hours= 1,200Wh. Your battery is 24V*100Ah=2,400Wh
Hi Nick thank you for great information I also have 24v lifep04 battery with 3kw hybrid inverter ,the battery will only charge to 28.4v and and stay there the bulk charge setting is 29v and float at 27v Im from South Africa and here we have so called load shedding so when power go off the battery volts drop slowly within 5min to 26.4 v and then it will stay there for the 2hours power down im only use +-6%180to 200watts on inverter Am I doing someting wrong or is this normal thank you
The voltages seem normal to me. Are you sure your inverter only uses 200W? The hybrid inverter will also use 50 watts all the time. Maybe you can add a shunt to see the capacity of your battery instead of relying on the voltage from LiFePO4 which is not dependable.
I have a 3.2 volt LiFePo4 cell that is completely dead. I am trying to figure out which is the positive terminal on the battery. No markings but one terminal is bronze colored and the other is silver colored. Which is the positive terminal?
You can easily see that when you put a multimeter on the terminals. If the positive is placed correctly, then the value will be normal. If it is placed in reverse, then there will be a – sign on the display.
Hi Nick,
Do you have an android/microsoft application that automatically arrange/group lifepo4 battery based on its capacity?
No. Why would you want to have that? You can test the cells individually and write it on a sticker an paste it on the cell.
I buy 128 pcs 32650 lifepo4 battery, the problem is they have different capacities. At first, I assembled it 16s8p without considering the capacity and 1 parallel array is easy to full charge and the BMS keeps on turning off when it reaches 3.65V while other array is 3.4V only. That’s why I am searching for an application that will automatically arrange the batteries so that the capacity on all parallel arrays are the same.
Morning Nick.
First of all great information on the site. Much appreciated.
I have built myself an 24v prismatic eve 3.2v 100ah cell battery. I have it configured 8s to give me 24v. I have a 8s. Daly BMS. Now I am looking to expand and see a deal on 230ah eve cells.
Can i put one 230ah and one 100ah cell in parallel making 330ah and then 8 of those in series for 24v? Will my discharge rate be limited to 1C (100amps) of the 100ah cells or can it go up to 330amps?
Another question, can i then use the 8s bms on all the parallel cell groups?
Sorry for all the questions. 🙏
can I configure
Hello Tomas,
You can parallel batteries with different capacity, but they need to have the same voltage.
Two packs in parallel increases the capacity, so you can draw 330A at 1C. You need a different BMS for the new battery.
Your battery will look like this: 8 cells 100Ah that make 24V at 100Ah and in parallel 8 cells 230Ah that make 24V at 230Ah. Parallel these together to a busbar.
Thanks so much for the quick reply. Ok that helps a lot.
They are the same cells of 3.2V.
So all I need is another 8s BMS for the new battery.
My inverter is only 3kw, so another 120Amp BMS would do right?
much appreciated.
Hi Nick,
first, thanks for your time.
I have a 10 Kw felcity lithium battery LBPA grade A+.
I have scanned the cells and showed a total of 54.05V with a maximum of 3391 mv per cell and a minimum of 3366 mv per cell.
is a delta of 28 mv bad?
shall I get back to the supplier and change the cells with 3366 mv?
I have monitored my battery (felicity 10 Kw LBPA grade A+) and for an average of 504.65 Watt within a period of 5 hours and 25 minutes, the battery went down from 96% to 63%.
Is it a good range ?
Thank you in advance
Delta is really good. It’s only 0.028V.
505W*5.5hours=2777Wh. That is 27% of 10.000Wh. 96%-63%=33%
You are all good and the battery is ok.
thank you Nick for your quick response.
much appreciated
another question please.
I have monitored my battery (felicity 10 Kw LBPA grade A+) and for an average of 504.65 Watt within a period of 5 hours and 25 minutes, the battery went down from 96% to 63%.
Is it a good range ?
Thank you
Hello Nick,
Thanks for making out time to assist with your responses.
Please how can I convert 2600mv to volt. This unit is what was used on my BMS settings
2600mV x 1000=2.6V
mV = millivolts, you have to multiply by 1000 to get volts.
kV = kilovolts, you have to divide by 1000 to get volts.
Thanks for the explanation. I’ll work with this.
One question I have been trying to find but there seems to be no answer. I have 8 AGM batteries I purchased used but are still in very good condition. I keep them stored in my basement because I don’t use them, but I keep a 10 amp trickle charger on all the batteries connected in parallel. My question is, how long can AGM batteries sit fully charged like this? I know some people say AGM batteries have a life span of about 7-10 years, but what if you don’t use them? Can they stay fully functional for years in this state?
Yes, they will remain the same capacity. However natural degradation of the batteries will still continue. But this wouldn’t be much. You can store them like this for a few years and still use them. You can do a desulfation if it comes with your charger every year.
Hello Nick –
Please does your above response apply to Lithium battery also? I installed a solar inverter using 24v 200Ah lithium battery. I only visit this apartment like once a year. Should I leave the battery on charge from the panel or completely shutdown the unit until next visit. Or should I put a load on the battery on continuously discharge and charge until my next visit? Am worried about how this may affect the lifespan hence seek advice.
Hello Steve, charging the battery before you leave and disconnecting all the loads including inverter will be sufficient.
Hello, I have a 50 AN LiFePOS4 battery (4s), it is almost brand new, only been charged a few times, today while out on the water (Trolling Motor application) the motor stopped running! When I got home, I checked battery voltage and it was 9V!! I tried to put it on charge, but it wouldn’t take a charge, the charger says, “Low Battery Voltage” .. The battery has a built in BMS with over voltage, and over discharge protection? is there a way to put a trickle charge on the batt to get it up to minimum voltage?
The 9V is not the actual battery voltage, it’s a voltage that the BMS put out after being depleted to 0%. You should be able to charge it again. What charger do you have? It’s best to send me an email for quicker responses.
I knew nothing about solar so I bought your book. You took the time to start slow n easy then got deeper into the specifics.
I can now go off grid for weeks at a time and have the basics powered up 24/7 until….whenever.
This article brought a couple more details to light.
Thanks.
Thanks for your support Bobbo!