# How do I calculate the carbon footprint of a lead-acid battery?

Canonical: https://senseible.earth/answers/lead-acid-battery-carbon-footprint-per-unit

Lead is most of the total. Multiply lead and alloy per battery by your supplier's factor, where recycled secondary lead is far lower than primary. Add the plastic case, separators, acid, grid casting and formation electricity. Divide by batteries passed, and report each Ah rating separately.

## Materials

- Lead and lead alloy for grids and oxide: ask your smelter for a per-tonne figure and its recycled share.
- Polypropylene case and lid.
- Separators, sulphuric acid and terminals.

## Plant energy

- Lead melting pots and grid casting: PNG, LPG or electricity.
- Oxide mills and pasting lines.
- Formation charging: a large electricity draw, often the biggest plant line.

## Per battery

Report per battery for each Ah rating, and per kWh of capacity if a buyer compares chemistries. End-of-life recycling is a separate stage, not a deduction.

## Worked example: battery plant per unit (one month)

- Electricity: 300,000 kWh x 0.710 = 213,000 kg CO2
- Melting PNG: 15,000 SCM x 2.05 = 30,750 kg CO2
- Batteries passed: 40,000
- Plant total: 243,750 / 40,000 = 6.09 kg CO2 per battery
- Add lead, plastic, separators and acid for the full figure

Inputs are illustrative; use your own bills and production records.

## What Senseible does here

Senseible reads the plant's electricity bills (CEA grid factor 0.710 kg CO2 per kWh, CO2 Baseline Database version 21.0) and fuel invoices (IPCC 2006 defaults) into a fingerprinted Scope 1 and 2 record, the plant-level input to a per-unit figure. Bought-in materials go to the supplier evidence trail; product reports are self-declared drafts.

- [Product carbon footprint calculator](https://senseible.earth/calculators/product-carbon-footprint)
- [Secondary lead smelter CO2 per tonne](https://senseible.earth/answers/secondary-lead-smelter-co2-per-tonne)
- [Lead-acid battery recycling emissions](https://senseible.earth/answers/lead-acid-battery-recycling-emissions-per-tonne)
- [Automobile industry](https://senseible.earth/industries/automobile)

Sources: [GHG Protocol Product Standard](https://ghgprotocol.org/standards), [ISO 14067:2018, Carbon footprint of products (iso.org)](https://www.iso.org), [IPCC 2006 Guidelines, Volume 2 Energy (fuel defaults)](https://www.ipcc-nggip.iges.or.jp/public/2006gl/vol2.html), [CEA CO2 Baseline Database, version 21.0](https://cea.nic.in/cdm-co2-baseline-database/?lang=en)

Last reviewed 2026-10-20.