# Battery Series/Parallel Calculator API

> For the complete documentation index, see [llms.txt](/llms.txt).

Calculate battery-pack voltage, capacity, energy, resistance, discharge current and runtime from an S/P layout.

Use this endpoint to add the tool to your app, site, workflow, or agent without rebuilding formulas, validation, examples, and docs.

- Slug: `battery-series-parallel-calculator`
- Category: `miscellaneous`
- Version: `2026-04-22`
- Credits per successful call: 1
- Starts on: free
- Max payload: 65536 bytes
- Privacy mode: `hash_only`
- Available on: free, starter, pro, business, scale

## Endpoint

`POST https://api.miniwebtool.com/v1/tools/battery-series-parallel-calculator/run`

## Request body

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `chemistry` | `str` | no | liion | lipo | lifepo4 | lto | nimh | nicd | lead | alkaline | custom Choices: liion, lipo, lifepo4, lto, nimh, nicd, lead, alkaline, custom |
| `series` | `int` | no | cells in series |
| `parallel` | `int` | no | cells in parallel |
| `cell_capacity_mah` | `float` | no | capacity of one cell in mAh |
| `custom_cell_voltage` | `float` | no | nominal cell voltage when chemistry is custom |
| `resistance_mohm` | `float` | no | optional internal resistance per cell in milliohms |
| `c_rate` | `float` | no | optional continuous discharge C-rate |
| `load_current` | `float` | no | optional load current in amps |

## Example request

```json
{
  "chemistry": "liion",
  "series": 4,
  "parallel": 2,
  "cell_capacity_mah": 3000,
  "custom_cell_voltage": 3.7,
  "resistance_mohm": 20,
  "c_rate": 3,
  "load_current": 2
}
```

## cURL

```bash
curl -X POST https://api.miniwebtool.com/v1/tools/battery-series-parallel-calculator/run \
  -H 'Authorization: Bearer mwt_live_YOUR_KEY' \
  -H 'Content-Type: application/json' \
  -d '{"chemistry":"liion","series":4,"parallel":2,"cell_capacity_mah":3000,"custom_cell_voltage":3.7,"resistance_mohm":20,"c_rate":3,"load_current":2}'
```

## Response envelope

```json
{
  "request_id": "01K...",
  "tool": "battery-series-parallel-calculator",
  "tool_version": "2026-04-22",
  "credits_used": 1,
  "result": {}
}
```

## Errors

Errors are RFC 7807 `application/problem+json`. Branch on `code`, not `title`.

## MCP

Agents can discover and call this tool through `https://api.miniwebtool.com/mcp` or `https://api.miniwebtool.com/v1/mcp` using MCP `tools/list` and `tools/call`.

## Frequently asked

### What does the Battery Series/Parallel Calculator API do?

Calculate battery-pack voltage, capacity, energy, resistance, discharge current and runtime from an S/P layout. Use it to add this utility without rebuilding formulas, validation, examples, and documentation.

### How much does one call cost?

1 credit per successful call. Failed calls do not bill.

### What parameters are required?

Required fields: (none). Full schema at `https://api.miniwebtool.com/v1/openapi.json`.

### Is this deterministic?

Yes. Same input, same output. Tool version: 2026-04-22.