# PAS 63100 — fire safety when a home battery sits alongside your V2L backup > PAS 63100:2024 is the fire-safety specification for a **fixed (stationary)** home battery. It is the standard for any companion home battery that sits alongside a V2L backup — it governs where the battery may go, fire detection, stored-energy limits and impact protection near where the car parks. It does **not** cover the EV's own traction battery, and it **explicitly excludes** second-life batteries, including repurposed EV packs. The battery install is still designed and certified under BS 7671, with PAS 63100 layering fire safety on top. **Safety frame.** This is education, not an instruction to carry out work. Work connecting V2L equipment to fixed wiring is safety-critical and may be notifiable under Part P. It must be designed, installed, inspected and tested by a competent person to the current edition of BS 7671. Vehicle manufacturers generally do not sanction back-feeding fixed wiring from V2L outlets; follow manufacturer instructions. ## In short - PAS 63100:2024 is fire safety for **fixed domestic battery storage** — published 20 March 2024, the sole edition. - It is for a **companion home battery**, not the EV's traction battery, and it **excludes second-life / repurposed EV batteries**. - It favours **outdoor or fire-separated locations** and restricts higher-risk domestic locations — relevant near a garage where the car charges. - Battery install follows **BS 7671** (with the IET EESS Code of Practice); PAS 63100 adds the fire-safety layer and an installer **statement of conformity**. - Numeric stored-energy limits and ratings are in the PAS — cite them by clause; we do not reproduce the figures. **Where this stops:** This explains what PAS 63100 requires. The battery's selection, siting and certification are competent-person work — and a repurposed EV pack is outside this specification entirely. ## What PAS 63100 is for PAS 63100:2024 is a Publicly Available Specification (a fast-track BSI document, not a full British Standard) for the **fire safety** of small, fixed rechargeable-battery energy storage systems in dwellings. It reduces the chance a home battery becomes a source of ignition, and limits the consequences if one does. It is **not** a wiring standard — the electrical installation is still governed by BS 7671. ## Where it fits with V2L A V2L backup uses the **car** as the source. PAS 63100 governs a separate **fixed home battery** you might run alongside it — for example to store cheap overnight energy. The boundary matters: the EV's own traction battery is a moving vehicle battery, outside this PAS, and a **repurposed EV pack used as fixed storage is explicitly excluded** (Clause 1, NOTE 4) — that route falls back on a BS 7671 Reg 511.2 declaration with no settled standard. > **Siting near the garage** — Because PAS 63100 favours outdoor or fire-separated locations and adds impact protection near vehicle areas, where the car parks and charges directly affects where a companion battery may go. This is a competent-person siting decision against the PAS. ## The clauses that matter The reference card distils the clauses — scope and the second-life exclusion, the deferral to BS 7671 and the IET EESS Code, location rules, impact protection, the power-conversion-equipment standards, and the notices and conformity statement. The citation/edition is checked (public-primary); the clause substance is pending a licensed/source-text check. We cite them by number; the numeric stored-energy limits stay in the PAS. ### How this is made and proven compliant **What governs it:** PAS 63100:2024 (fire safety) layered on BS 7671 for the electrical installation; BS EN 62109-2 for the power-conversion equipment (the hybrid inverter/charger); IET Code of Practice for Electrical Energy Storage Systems as application guidance **Who may do it:** Design, installation and certification by a competent person to BS 7671, with the PAS 63100 fire-safety requirements and statement of conformity. Notifiable work under Part P (England; devolved nations differ). **How compliance is demonstrated:** BS 7671 initial verification + certificate for the battery installation; An installer PAS 63100 statement of conformity appended at initial verification; Battery-present notices fitted at the required positions ## FAQ ### Does PAS 63100 apply to my EV's battery? No. It covers fixed, stationary home batteries. The EV's traction battery is a vehicle battery outside its scope, and a repurposed EV pack used as fixed storage is explicitly excluded. ### Can I reuse an old EV battery as home storage under PAS 63100? Not under PAS 63100 — second-life batteries are excluded. That route has no settled domestic standard and falls back on a BS 7671 declaration; treat it with caution and competent-person design. ### Does PAS 63100 replace BS 7671 for a home battery? No. The battery is still designed, installed and certified to BS 7671 (with the IET EESS Code of Practice). PAS 63100 adds the fire-safety layer and a statement of conformity on top. --- _Author: Martin — qualified UK electrician (BEng Mech Eng; vehicle mechanic)._ _Last reviewed: 14 June 2026. Written against: BS 7671:2018 + A4:2026._ _Status: published. General information, not project-specific design advice._ _[How we source this](/methodology) — evidence hierarchy, confidence flags and source policy._ ## Sources 1. PAS 63100:2024 — Protection against fire of battery energy storage systems for dwellings (BSI) — https://knowledge.bsigroup.com/products/electrical-installations-protection-against-fire-of-battery-energy-storage-systems-for-use-in-dwellings-specification (cited by clause only; numeric limits not reproduced) 2. V2L Workshop standards library — PAS 63100 reference card (internal)