Battery Pack Series/Parallel Configurator

Inspectable records

Ledger state

The current ledger marks this instrument verified clean within the source-bound verification corpus.

Area

Electrical & Electronics Engineering — Circuits, Power Systems, Electronics Lab

Tranche

tranche-4

Evidence ID

t4-126

Ledger rows

1

No ledger note is attached.

Review findings

The core series/parallel arithmetic is standard and correct under the stated ideal assumptions. The specification needs an explicit voltage convention (nominal, maximum, or operating range), explicit validation constraints for S and P, and either removal of the optional weight output or a defined weight formula and required inputs.

Formula and scope findings

• Vpack=S·Vcell, Cpack=P·Ccell, and Wh=Vpack·Cpack are correct for identical cells in an ideal SxP arrangement.
• The formulas do not account for voltage sag, usable-depth-of-discharge limits, charge/discharge efficiency, cell mismatch, wiring losses, or BMS limits; outputs are therefore nominal/theoretical values.
• The listed optional weight estimate has no formula, cell-mass input, enclosure-mass input, or definition of whether it is an estimate or a measured result.

Unit assumptions

• Vcell is in volts (V), Ccell is in ampere-hours (Ah), and Wh is watt-hours.
• Vcell and Ccell are nominal cell ratings; Wh is nominal stored energy, not guaranteed usable energy.
• S and P are positive integer counts: S is the number of cells in series and P is the number of parallel strings.
• Cells in every series and parallel position are assumed identical and connected in a conventional SxP topology.
• If capacity is supplied in mAh, it must be divided by 1000 before applying Cpack=P·Ccell; for example, 2500 mAh=2.5 Ah.
• The spec does not explicitly state nominal versus maximum/minimum cell voltage, so the voltage interpretation is ambiguous.

Boundary hardening

Recorded hazards

• Reject S<=0 or P<=0; zero or negative counts are physically invalid and can produce zero or nonsensical pack ratings.
• Require S and P to be integers; fractional cell counts are invalid.
• Reject missing, nonnumeric, zero, or negative cell voltage and capacity inputs.
• Avoid division by zero in any future reverse-calculation feature when deriving S, P, or cell values.
• Prevent accidental mixing of mAh and Ah; silently treating 2500 mAh as 2500 Ah creates a 1000-fold capacity and energy error.
• A pack's actual usable energy is lower or different than nominal Wh depending on cutoff voltage, load, temperature, aging, and efficiency.
• A weight output without a defined model must not be presented as an authoritative result.

Errata and corrections

No applied erratum is attached to this unique-name record.

Inspectable example

4 review vectors are recorded. One source-bound sample is shown below.

{
  "inputs": {
    "cell_voltage_V": 3.7,
    "cell_capacity_Ah": 2.5,
    "S": 3,
    "P": 4
  },
  "expected_outputs": {
    "pack_voltage_V": 11.1,
    "pack_capacity_Ah": 10,
    "pack_energy_Wh": 111
  },
  "working": "Vpack=S·Vcell=3·3.7=11.1 V. Cpack=P·Ccell=4·2.5=10 Ah. Wh=Vpack·Cpack=11.1·10=111 Wh."
}

Related workflows

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json · VERIFIED_CLEAN
• evidence-tranche4/tranche4-results.json