1Cell

Cell presetNMC/NCA — representative typical values; check the actual cell datasheet for a specific part number.

Nominal voltage (V)

Capacity (Ah)

Internal resistance (mΩ)

Cell mass (g)

Max continuous discharge (C-rate)Max continuous current for one cell = C-rate × capacity (Ah).

2Pack configuration

Series count (S)Number of cells/groups in series — sets pack voltage.

Parallel count (P)Number of cells in parallel per series group — sets pack capacity.

Load current (A)Used to check voltage sag and discharge current against the pack's continuous rating.

Results

Pack voltage (nominal)

46.8V

Pack capacity

12Ah

Pack energy

562Wh

Pack internal resistance

113.75mΩ

Total cells

Pack mass (cells only)

2.34kg

Max continuous discharge

24A

Voltage under load

41.11V

sag 5.69 V

Reference & assumptions

New to Series / Parallel Cells? Read the guide: Battery Pack Configuration: What S×P Does to a Cell — a plain-language explainer of the standard behind this calculator.

Standard series/parallel circuit combination applied to a single cell's spec: cells in series add voltage (and their internal resistances add), cells in parallel add capacity (and their internal resistances combine as R/P). Cell presets are representative typical values for common formats (18650/21700 Li-ion, pouch, LiFePO4 prismatic) — real cells vary by manufacturer and specific part number, so check the actual datasheet before finalizing a design. This tool does not model cell-to-cell manufacturing variation/imbalance, temperature effects on resistance/capacity, or aging/cycle life — all of which matter for a real pack design and BMS sizing.

Validated: checked against a hand-worked 10S4P example using the 18650 preset (3.6 V, 3.0 Ah, 35 mΩ, 45 g, 2C) — this calculator returns 40 cells, 36 V, 12 Ah, 432 Wh, 87.5 mΩ, and 1.8 kg, and at a 20 A load, 1.75 V of sag to 34.25 V, all matching the standard series/parallel combination rules exactly.

Calculation steps

1. Pack voltage and capacity (series adds voltage, parallel adds capacity)

V_pack = S · V_cell, Ah_pack = P · Ah_cell

S = 13, P = 4, V_cell = 3.6 V, Ah_cell = 3 Ah

V_pack = 46.8 V, Ah_pack = 12 Ah

2. Pack energy

Wh_pack = V_pack × Ah_pack

561.6 Wh (0.562 kWh)

3. Pack internal resistance (P parallel cells share current, S groups in series)

R_pack = S × (R_cell / P)

R_cell = 35 mΩ

R_pack = 113.75 mΩ

4. Total cell count and pack mass

N = S × P, mass = N × mass_cell

N = 52 cells, mass ≈ 2.34 kg

5. Max continuous discharge current (from cell C-rate)

I_max = P × Ah_cell × C_rate

C-rate = 2C

I_max = 24 A

6. Voltage sag under load

V_sag = I_load × R_pack, V_loaded = V_pack − V_sag

I_load = 50 A

V_sag = 5.69 V, V_loaded = 41.11 V — exceeds max continuous discharge current

Battery Pack Series/Parallel Calculator