What should the battery do?
Pick an application on the Usage tab first. Sizing will show only the relevant choices.
🧮 Size from the duty Pro
The route, the schedule, the charge windows and the life go in; the nameplate
comes out with THE CONSTRAINT THAT DECIDED IT named — every constraint at end of life, winter
as the design day. Then one click puts the answer on the bench: the sized pack runs through
the simulated service day, and the two engines agree or say exactly why not.
Open the sizer
Sizing basis
Choose an application and operating goal.
Your recommendation
Complete the sizing choices to see one clear recommendation.
Engineering details
The selected goal is converted internally into battery power over time. Engineers and software integrations can inspect or replace that trace here.
Recalculate from the current peak power
Measured data or another profile
Use this only when you have measured data or need to compare a non-default duty.
Profile library
📁 Upload measured battery power (CSV)
Two columns: seconds, watts — positive = battery discharge, negative = battery charging.
Any logger or Excel export works.
Download a sample CSV .
Available space
Box
Round
L-shape
Stepped
Draw
📁 Upload outline from CAD — DXF · SVG · CSV · JSON
A Usage-tab preset pre-fills the typical bay for that application. Walls,
spacer gap, busbar headroom and the selected cooling system's space are subtracted
before packing.
Integration allowance 35%
Plan-area reserve for module walls, crash structure, manifolds and wiring
that the packer doesn't model. Calibrated against the Tesla Model 3 LR pack, where the
OEM realizes ~64% of the geometric ideal. Set 0 for bare-maximum geometry.
Cell cost basis
Over service life
Upfront
Estimates cell purchases over the target years and cost per nominal cycle-throughput
kWh, using your Usage settings (80% DoD by default). Excludes BMS, enclosure,
thermal hardware, labor, electricity, losses and calendar aging. Upfront is cells only.
Objective weights
Relative priorities for the multi-objective score. Pareto-optimal designs
(no other candidate is better on every objective) are marked regardless of weights.
Max fill — optimize space · cost · weight
Repack current S·P (min volume / fit check)
Architecture — modules, BMS & HV chain
How this pack is built up and switched: cells → modules (or cell-to-pack) →
pack → parallel racks for big systems, plus the BMS topology, precharge, contactors,
fuse, DC-DC and isolation the customer needs around the cells.
System — pack, HV chain & supervisory layer (tap to enlarge)
Inside the BMS — layer 2 (tap to enlarge)
BMS topology
Auto
Centralized
Master/slave
Wireless
Isolation bus context (UN R100 vehicle topology — no averaging)
Separate DC · 100 Ω/V
Connected AC/DC · 500 Ω/V
Separate AC · 500 Ω/V
UN R100 Rev. 3 §§5.1.3.1–5.1.3.2. The connected-bus
100 Ω/V exception requires documented protection on every AC bus and is not silently selected.
Marine IT systems need their declared earthing topology, class rules and flag-state basis instead.
EMS architecture (only shown when your application has an EMS)
Auto
Centralized
Hierarchical
Distributed
Assumptions (AFE channels, DC link, precharge duty, sensors)
Set S_mod when the mechanics fix the module first — a 30S module at
16-channel AFEs correctly gets 2 slave ICs.
AFE ICs run 14–25 channels; the DC-link capacitance belongs to the load's
inverter — replace the placeholder with its datasheet value. The precharge resistor is
sized for the stated repetition rate.
HV startup, current shunt & fast protection
Sensata-based calculators for the parts around the DC link. The curves show
what the circuit does; the plain-language verdict says what is qualified, missing or unsafe.
Archived parts are reference models only.
Precharge resistor and contactor
Calculator inputs and supplier evidence
Current-shunt selection
Duty, measurement and thermal model
Reference / supplier model
Sensata SFP200 · 108 mm² busbars · archived
Sensata SFP200 · 1/0 AWG cables · archived
Current supplier shunt · enter ratings
Fast-fault coordination
Run the short-circuit study first.
Detection and interrupter evidence
Charging
Expert detail — charger classes, connectors, strategy
Auto
3.6 kW
7.4 kW
11 kW
22 kW
🧭 BMS mode charts Pro
The battery fraction of Stateflow, pre-assembled: modes, guarded
transitions, latching faults. The chart is data — the diagram below is generated from it —
and every transition explains itself with the signal values that fired it. Run it against
the mission above, then take it to your controller as loop-free C, held to this
interpreter by an open conformance test.
Supervisor
Run against the mission
Generate C
🔥 Runaway investigation lab Pro
One cell goes — watch the event the way an investigator watches a test:
the cell map through time, the propagation order, which heat path carried the energy.
Battery questions only, no fire-CFD authoring; and it can never say "safe" —
only what the model observed.
Open the lab
The SYSTEM behind the cold plate: the loop (pump, radiator,
refrigerant chiller / heat exchanger, valves, heater), the BTMS control unit that runs it, and what
it costs the higher system. Derived from your selected cooling component, the pack's heat at
continuous load and the climate window.
Thermal management system
Auto
Air
Liquid
+Chiller
Loop & control (tap to enlarge)
The design, run through TIME: the application's load
profile drives an equivalent-circuit model of YOUR pack (OCV−I·R, coulomb counting) coupled to a
lumped thermal model (I²R in, cooling out). Watch SoC, voltage sag and temperature over the
mission — and see exactly when a pack runs empty, hits the voltage cutoff, overheats or refuses
winter charge.
Test protocol bench
A cycler for the simulated pack: charge, discharge, rest, pulse trains,
drive-cycle replay and repeats, written in a small protocol language or clicked together —
both edit the same protocol, and the run names why every block ended.
Open the protocol bench
⚙️ C code for your BMS Pro
This exact model — OCV, sag, cutoff hold, CV taper, winter charge inhibit,
coulomb counting, thermal — generated as portable C99 with a fixed-step, reentrant ABI
(init/step/reset/terminate), static memory, every loop bounded. The generated C is held to
this simulation step by step by an open conformance test — the proof ships with the tool,
not on a vendor's name. The header carries the same honesty as this tab: class-estimate OCV
and published DCIR, to be replaced with your measured data.
Generate C for this design
📈 Fit the model from your test data Pro
Upload a cycler trace and the class estimates above become YOUR cell's
measured curve: OCV from the rest points, resistance by least squares under load. The fit is
deterministic and judges itself in millivolts; where the data never went, it says
"interpolation", not numbers. Adopted, the measurement rides into the simulation and the
generated C with the dataset's digest attached. Nothing leaves your browser.
Fit
Every sensor THIS design needs, at its level — cell,
module, system, cooling loop. What the system does not need is not shown at all: a wearable
lists no coolant sensors, a drone no runaway detector. Counts feed the connector pin-out and
harness budget.
Your recommendation
Complete the sizing choices to see one clear recommendation.
🔍 Where every number comes from
The effective-value ledger: every load-bearing value in this design, with
its source named — measured, document-backed, class estimate, configuration, or derived
with the formula shown. A value's origin decides whether a review can believe it.
Show the ledger
Cell comparison
Tick two or more cells under
Design → Browse and compare cells to see how their compromises differ.
Download PDF
Download Word
Architecture report
Engineer's workbook
Animated visual decision report
The visual report is a self-contained, sub-minute animated HTML file using
this design's exact sizing, simulation, selected thermal hardware, semantic trace and
versioned 3D asset. The architecture report is a layered HTML page — select and open exactly
the level you care about (system → pack → module → cell, control, thermal, sensors).
The workbook (Excel) computes with live formulas over named cells, so you can check every
number against your own spreadsheet — edit it and send it back to teach the tool.
🤖 Copy this design for an AI assistant
Copies the whole design as JSON plus a short written brief, so you can paste it
into any chatbot and ask about it. To let an AI drive the designer directly — size a pack, run a
mission, compare cells — run the included MCP server on your machine (see
desktop/README.md).