CVP verified calculation capability

Battery runtime Calculation Capability

Estimate constant-load battery runtime from capacity, voltage, load (W load-side or A battery-side), DoD, and load-side efficiency (watts mode); optional u_* compose expanded uncertainty on t_h via Uncertainty Engine.

Electrical Capability ID electrical.battery_runtime version 1.2.1 CVP VERIFIED CURRENT Engineering

Model

Usable energy (watts mode)

Usable energy (watts mode): E(Wh) = Ah × V × DoD × η
Runtime (load-side power): t(h) = E(Wh) ÷ P(W)
Usable energy (amps mode): E(Wh) = Ah × V × DoD
Runtime (battery-side current): t(h) = (Ah × DoD) ÷ I_battery(A)
mAh → Ah: Ah = mAh ÷ 1000

Modes: watts · amps

Inputs / Outputs

Canonical symbols for this capability. Agent schemas remain the contract.

Symbol	Quantity	Unit	Role
`capacity_Ah`	Battery capacity in amp-hours	—	input / output
`capacity_mAh`	Battery capacity in mAh; Ah = mAh/1000	—	input / output
`V`	Nominal pack voltage	—	input / output
`P`	Constant delivered load-side power	W	input
`dod`	Planning depth of discharge in	—	input / output
`eta`	Load-side delivery efficiency in	—	input / output
`u_capacity_Ah`	Optional standard uncertainty of capacity_Ah	—	input / output
`u`	Optional standard uncertainty of V	V	input / output
`u_P`	Optional standard uncertainty of P_W	W	input
`u_dod`	Optional standard uncertainty of dod	—	input / output
`u_eta`	Optional standard uncertainty of eta	—	input / output
`uncertainty_k`	Coverage factor for expanded U on t_h; default 2 when any u_* is set	—	input / output
`confidence`	Coverage probability instead of uncertainty_k	—	input / output
`I`	Constant battery-side discharge current	A	input
`u_I`	Optional standard uncertainty of I_A	A	input
`t_h`	Estimated runtime	—	output
`t_d`	Estimated runtime	—	output
`E_Wh`	Usable energy in Wh	—	output
`uncertainty`	Present when any u_* is provided; UncertaintySummary via engineering	—	output

Assumptions / Validity

Declared scope for this capability. Do not use it outside this domain.

Assumptions

Constant load; ideal flat voltage until capacity is exhausted.
DoD and η are independent planning knobs, not chemistry models.
Amps mode I_A is battery-side discharge current; η does not enter t_h.
When u_* are set, first-order GUM sensitivity with independent inputs (no ρ on this page).

Example

One numerical check. The calculator page holds worked steps and FAQ.

10 Ah, 12 V, 20 W, DoD 0.8, η 0.9 → t_h = 4.32, E_Wh = 86.4

Open this example in the calculator

Trust

CVP VERIFIED · CVP protocol 1.0.0-proposed · Engineering assurance. Computational verification is defined by CVP. Supplemental domain review (internal) and named expert review are defined by the Review policy and do not by themselves determine CVP conformance.

CVP: CVP VERIFIED · CVP protocol 1.0.0-proposed · Engineering assurance· View Manifest · CVP overview · Specification
Assurance: Engineering
Declared partition coverage: PASS · 3/3 declared partitions (watts, amps, invalid-domain)
Calculation version: 1.2.1
Verification: 25/25 calculation tests · 5/5 legacy golden · 10/10 legacy boundary · 10/10 legacy property
Production surface contract: 8/8
Versions: Calculation 1.2.1 · CVP protocol 1.0.0-proposed · Evidence 2026-09-11.schema-coverage-u
Verification revision: 2026-09-11.schema-coverage-u · 10/10 property · digest 058cf03cbe19
Reference: O1 model · O2 expected_values · O2 numerical_behavior
Interfaces: PASS · UI (SSR) / REST / MCP
ui-ssr is query-result HTML, not a live browser session.
CVP suite: 3/3 golden · 9/9 CVP boundary · 7/7 invalid · 10/10 property · 1/1 cross-interface · 6/6 CVP contract
Supplemental domain review: Internal · Pass · electrical-engineer
Named expert review: Not performed
Version lock: Supported (409 VERSION_MISMATCH)
Artifact consistency: Build verified · 1.2.1 (workspace artifacts agree)
Review-policy tier: Internally reviewed — catalog token internally_reviewed; supplemental; not CVP status

This calculator CURRENT · Public schema 1.2.1 matches · Semantic contract ✓ · Production attested · Public/cache ✓ · Origin ✓

Call this capability

Human page, REST, and MCP share the same engine and calculation_version. Build verified hashes workspace artifacts only. After deploy, attest:production GETs canonical URLs twice — the public/cached view an Agent actually hits, and origin — including every /capabilities/{id} HTML page. Public Capability HTML version must match catalog before production attestation passes. Live Trust rows above fetch /.well-known/calculatorx-production-attestation.json and the output schema const. Build hashes: release integrity. That proves currently published page / engine / schema / evidence / MCP agree — not that a historical version is independently immutable. Reference Calculation Standard — Production surface contract 8/8.

curl -sS -X POST 'https://www.calculatorx.com/api/v1/calc/battery-runtime' \
  -H 'Content-Type: application/json' \
  -d '{"inputs":{"mode":"watts","capacity_Ah":10,"V":12,"P_W":20,"dod":1,"eta":1},"calculation_version":"1.2.1"}'

{
  "inputs": {
    "mode": "watts",
    "capacity_Ah": 10,
    "V": 12,
    "P_W": 20,
    "dod": 1,
    "eta": 1
  },
  "calculation_version": "1.2.1"
}

POST /api/v1/calc/battery-runtime. This is a POST calculate endpoint — do not GET it.

Full REST contract: REST API docs.

Tool id: battery-runtime
Engine: battery-runtime
REST: POST /api/v1/calc/battery-runtime
MCP: execute_calculation with capability_id: "electrical.battery_runtime"
Agent input schema: Canonical (MCP / Agent)
Output schema: JSON Schema (latest)
Versioned input schema: Immutable pin (1.2.1)
Versioned output schema: Immutable pin (1.2.1)

Operations

Declared calculation modes for this capability.

watts
amps

References

Human-readable sources plus CVP reference evidence classes.

Sources

IEC 60050 — International Electrotechnical Vocabulary — Electric battery capacity and related quantities
IEC 61960 series (portable secondary lithium) — Capacity / performance concepts for portable Li cells and batteries
Victron Energy — Battery capacity and Peukert exponent — Battery monitor documentation (BMV)
NIST Guide to the SI (SP 811) — Coherent derived units for energy and time

Reference evidence classes: O1 model · O2 expected_values · O2 numerical_behavior

Try with an agent

Inspect, then execute. Same engine as REST and the human calculator.

curl -sS -X POST 'https://www.calculatorx.com/mcp' \
  -H 'Content-Type: application/json' \
  -H 'MCP-Protocol-Version: 2026-07-28' \
  -H 'Mcp-Method: tools/call' \
  -H 'Mcp-Name: inspect_capability' \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"inspect_capability","arguments":{"capability_id":"electrical.battery_runtime"},"_meta":{"io.modelcontextprotocol/protocolVersion":"2026-07-28","io.modelcontextprotocol/clientInfo":{"name":"calculatorx-docs-example","version":"1.0.0"},"io.modelcontextprotocol/clientCapabilities":{}}}}'

curl -sS -X POST 'https://www.calculatorx.com/mcp' \
  -H 'Content-Type: application/json' \
  -H 'MCP-Protocol-Version: 2026-07-28' \
  -H 'Mcp-Method: tools/call' \
  -H 'Mcp-Name: execute_calculation' \
  -d '{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"execute_calculation","arguments":{"capability_id":"electrical.battery_runtime","inputs":{"mode":"watts","capacity_Ah":10,"V":12,"P_W":20,"dod":1,"eta":1},"calculation_version":"1.2.1"},"_meta":{"io.modelcontextprotocol/protocolVersion":"2026-07-28","io.modelcontextprotocol/clientInfo":{"name":"calculatorx-docs-example","version":"1.0.0"},"io.modelcontextprotocol/clientCapabilities":{}}}}'

Pin calculation_version (1.2.1) when the result must stay reproducible.

Inspect the trust tier and required assurance level before execution. Full protocol notes: MCP docs.