Lifepo4 Float Voltage

Quick Facts About LiFePO4 Batteries and Lifepo4 Float Voltage

  1. Nominal Voltage per Cell: 3.2 V (often you’ll see 3.2–3.3 V).
  2. Full Charge Voltage per Cell: 3.65 V.
  3. Typical Float Voltage per Cell: 3.375V (LiFePO4 does not necessarily require a float, but if your charger/controller does have a float stage, these are typical values).
  • Recommended Charge per Cell: 3.55 V
  • Maximum Charge per Cell: 3.65 V
  • Float Voltage per Cell: 3.375 V
  • Low Voltage Cutoff per Cell: 2.8 V

These settings are our own recommendations, we base these figures on many years of community feedback and consultation with other professionals. We believe these will offer you the best balance of lifespan and usage.

lifepo4 SOC chart cell single

A basic SOC % to voltage chart for quick and easy reference

These numbers are affected by various factors such as who the manufacturer is, what temperature it is, the grade and age of the cell.
These are a reference for new LFP cells especially prismatic cells manufactured by companies similar to EVE Energy or CATL.

Use these 12v, 24v and 48v

sections below to check your battery and chargers are set with the most accurate general LFP settings

4S (12.8 V) LiFePO4 Battery
Parameter
Value
Notes
Nominal Voltage
12.8 V (4 × 3.2 V)
Standard “label” voltage for a 4S LFP pack.
Recommended Charge Voltage
14.2 V (4 × 3.55 V)
Preferred charging level to balance performance and longevity.
Maximum Charge Voltage
14.6 V (4 × 3.65 V)
Typically used briefly for topping off; not ideal for continuous charging.
Float Voltage
13.5 V (4 × 3.375 V)
If using a float stage, keep it at or below this voltage.
Low Voltage Cutoff
11.2 V (4 × 2.8 V)
Avoid discharging below 2.8 V per cell to prevent damage.
Resting Voltage (approx.)
~13.2 V
About 3.3 V/cell when neither charging nor under significant load.
12v 300ah battery box
280Ah, 300Ah, 304Ah 314Ah

8S (25.6 V) LiFePO4 Battery
Parameter
Value
Notes
Nominal Voltage
25.6 V (8 × 3.2 V)
Standard “label” voltage for an 8S LFP pack.
Recommended Charge Voltage
28.4 V (8 × 3.55 V)
Preferred charging level to balance performance and longevity.
Maximum Charge Voltage
29.2 V (8 × 3.65 V)
Typically used briefly for topping off; not ideal for continuous charging.
Float Voltage
27.0 V (8 × 3.375 V)
If using a float stage, keep it at or below this voltage.
Low Voltage Cutoff
22.4 V (8 × 2.8 V)
Avoid discharging below 2.8 V per cell to prevent damage.
Resting Voltage (approx.)
~26.4 V
About 3.3 V/cell when neither charging nor under significant load.
battery box
8s_25.6V_280ah-314ah-304ah
16S (51.2 V) LiFePO4 Battery
Parameter
Value
Notes
Nominal Voltage
51.2 V (16 × 3.2 V)
Common “label” voltage for a 16S LFP pack.
Recommended Charge Voltage
56.8 V (16 × 3.55 V)
Preferred charging level to balance performance and longevity.
Maximum Charge Voltage
58.4 V (16 × 3.65 V)
Typically used briefly for topping off; not ideal for continuous charging.
Float Voltage
54.0 V (16 × 3.375 V)
If using a float stage, keep it at or below this voltage.
Low Voltage Cutoff
44.8 V (16 × 2.8 V)
Avoid discharging below 2.8 V per cell to prevent damage.
Resting Voltage (approx.)
~52.8 V
Around 3.3 V/cell when neither charging nor under significant load.


Tips for Using These Charts

Use the Recommended Charge Voltage (3.55 V/cell) for routine charging.

  1. Only reach Maximum Charge Voltage (3.65 V/cell) briefly if the BMS or charger calls for a top-off.
  2. Float Voltage (3.375 V/cell) is optional; many LiFePO4 systems don’t float in the same manner as lead-acid.
  3. Low Voltage Cutoff (2.8 V/cell) is the absolute minimum. Staying above it ensures longer battery life.
  4. Check Manufacturer Specs if they differ from these standard guidelines.
State of Charge (SoC) vs. Voltage (Rest & Load)

The next table provides approximate voltages for different States of Charge (SoC) at 25 °C. Each SoC row shows the “Volt per cell” under two conditions:

  • rest: The battery resting or lightly loaded.
  • load: The battery under typical discharge load.
SoC (25 °C temp)
Rest Voltage
0.33C Load Voltage
100.00%
3.50
3.40
99.00%
3.45
3.35
90.00%
3.35
3.32
70.00%
3.30
3.30
40.00%
3.30
3.27
30.00%
3.25
3.24
20.00%
3.22
3.21
17.00%
3.20
3.15
14.00%
3.15
3.12
9.00%
3.10
3.00
0.00%
2.60
2.50

Those per-cell values then scale to 12 V (4S), 24 V (8S), and 48 V (16S) packs, again shown as “rest” and “load” columns.

.This Table is a combined table of single cell voltages, and then the common 4S, 8S and 16S configurations

SoC
Cell Rest (V)
Cell Load (V)
4S Rest (V)
4S Load (V)
8S Rest (V)
8S Load (V)
16S Rest (V)
16S Load (V)
100.0%
3.50
3.40
14.00
13.60
28.00
27.20
56.00
54.40
99.0%
3.45
3.35
13.80
13.40
27.60
26.80
55.20
53.60
90.0%
3.35
3.32
13.40
13.28
26.80
26.56
53.60
53.12
70.0%
3.30
3.30
13.20
13.20
26.40
26.40
52.80
52.80
40.0%
3.30
3.27
13.20
13.08
26.40
26.16
52.80
52.32
30.0%
3.25
3.24
13.00
12.96
26.00
25.92
52.00
51.84
20.0%
3.22
3.21
12.88
12.84
25.76
25.68
51.52
51.36
17.0%
3.20
3.15
12.80
12.60
25.60
25.20
51.20
50.40
14.0%
3.15
3.12
12.60
12.48
25.20
24.96
50.40
49.92
9.0%
3.10
3.00
12.40
12.00
24.80
24.00
49.60
48.00
0.0%
2.60
2.50
10.40
10.00
20.80
20.00
41.60
40.00

Note: Actual voltages can vary slightly with temperature, battery condition, and specific manufacturer chemistry.

Storage Guidelines:

Store batteries (longer than 1 month) indoors in a dry, clean environment between 0 °C and 35 °C (32 °F–95 °F).
Avoid contact with corrosive substances, fire, or direct heat sources.
Charge and discharge the battery every 6 months if in long-term storage.

Recommended storage SoC is 30–50%.

Operating Temperature Ranges:
Discharge: –10 °C (min) to +50 °C (max)
Charge: +2 °C (min) to +50 °C (max)

Manufacturer Specs: Always refer to the specific datasheet for exact values.

All of these values are guidelines only, the relationship to temperature and current draw, will affect cycle life.