Li-ion Pack Metrics Calculator

Cell preset & parameters

Single 18650/21700-style cell

Cell preset Loads nominal specs into the fields below

Nominal voltage V

Capacity Ah

Max cont. current A

DC resistance mΩ

Mass g

Volume cm³

Cell cost $

Cell Wh (derived)

— Wh/cell

Architecture & overheads

Series (S) sets pack voltage

Parallel (P) sets capacity/current

Electrical efficiency η (0–1)

Overhead mass kg

Overhead volume L

Overhead cost $

Total cells: — cells (—)

Advanced (sag, heat, fuse, transients, SoC)

Design current (pack) A

Duty cycle 0–1 avg load

Cell θJA °C/W steady-state

Cell thermal capacitance J/°C

Ambient temp °C

Max safe temp °C

Fuse headroom × cont. current

Loaded voltage @ I

— V

Output power @ I

— W

Heat per cell

— W

Pack heat

— W

Transient pulse (first-order RC, per cell)

Pulse current (pack) A

Pulse duration s

Time constant τ s

—

ΔT after pulse

— °C

Cell temp after pulse

— °C

Half-cooling time t½ ≈ — s

Fuse suggestions

Main fuse

— A

Per-string fuse

— A

SoC window sizing

SoC low

SoC high

Cycle-life derate

Usable energy (window)

— Wh

Window span

— % SoC

Module configurator

Cells per module (S_mod)

Cells per module (P_mod)

Modules in series (S_mods)

Modules in parallel (P_mods)

Module energy

— Wh

Module mass

— kg (cells only)

Key results

Pack voltage

—V

Capacity

—Ah

Energy (gross)

—Wh

Energy (η-adjusted)

—Wh

Max cont. current

—A

Cont. power

—W

Theoretical peak power

—W

Pack resistance

—mΩ

Mass, volume & cost

Cell mass

—kg

Pack mass (with OH)

—kg

Pack volume

—L

Energy density

—Wh/kg

Volumetric density

—Wh/L

Cell cost

$—

Pack cost (with OH)

$—

Cost per kWh

$—/kWh

Notes

This tool is a first-order engineering calculator. Always verify with manufacturer datasheets, safety standards, and detailed thermal/structural design before flight-critical use.