Can a LiFePO4 charger, charge a sodium-ion battery?

If you are building or evaluating a sodium-ion 
battery pack, one of the first practical questions 
is: do you need a special charger?

The short answer is no — and here is why.

THE VOLTAGE IS THE SAME

LiFePO4 cells charge to a maximum of 3.65V per cell.
NaFP (sodium iron phosphate) cells also charge to 
a maximum of 3.65V per cell.

For a 16S configuration — 16 cells in series — 
that gives a target charge voltage of:
16 × 3.65V = 58.4V

This is the standard voltage for every 48V LiFePO4 
charger on the market.

WHAT WE MEASURED

On the ZERITHIUM SIB-48 — our 16S1P NaFP 210Ah 
pack assembled in Aurora, Illinois — we used a 
standard 58.4V 20A LiFePO4 charger.

Results from the first charge cycle:

Charge current: 17.79A constant throughout 
the CC (constant current) phase

Temperature: 17.3°C to 20.0°C throughout — 
less than 1°C rise above ambient

BMS response: zero fault codes during the 
CC charge phase

The charger accepted the pack and held current 
at spec from the moment it was connected.

WHY IT WORKS

Both LiFePO4 and NaFP chemistry share the same 
charge voltage because of how the electrochemistry 
works at the cell level. The charger does not know 
or care what chemistry is inside — it targets a 
voltage and delivers current until the pack reaches 
that voltage, then tapers off.

The BMS handles chemistry-specific protection — 
overvoltage cutoffs, balancing thresholds, 
temperature limits. The charger just delivers 
current at the right voltage.

For our Seplos 200A smart BMS, the parameters 
were pre-configured for NaFP chemistry before 
shipment. The charger connection was plug-and-play.

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WHAT TO CHECK BEFORE CONNECTING

Confirm your charger's output voltage matches 
your cell count × 3.65V. For 16S that is 58.4V. 
For 8S it would be 29.2V.

Confirm your charger's output connector is 
compatible with your pack terminals. We used 
an M8 adapter to connect to the Seplos MASON-210 
front panel connectors.

Confirm the charger current rating suits your 
pack capacity. A 20A charger on a 210Ah pack 
is approximately a 0.1C charge rate — well 
within safe limits for NaFP chemistry.

THE FULL BUILD IS DOCUMENTED

We are publicly documenting the entire build 
process for the ZERITHIUM SIB-48 on YouTube 
at youtube.com/@saltrabatteries. Parts 1 through 4 
are live. Part 5 — the first charge cycle — 
is uploading soon.

The complete charge data log from our first 
cycle is available at saltrabatteries.com.