CFC · California Fire Code
What are the rules for retrofitting, reusing or repurposing ESS components?
If you change ESS parts that aren't identical, treat the work as a retrofit: get a construction permit, use listed components, keep UL‑9540 compliance, commission the system and record the work. Reusing batteries from EVs is prohibited unless the fire code official approves and the batteries were refurbished under UL 1974. **§ 1207.3.7** **§ 1207.3.9**
Last reviewed: July 6, 2026
What the code requires — 2-4 sentences
The California Fire Code requires that retrofits to an existing Energy Storage System (ESS) follow specific procedural and product-listing rules in § 1207.3.7 and that reused/repurposed storage batteries meet approval and refurbishing standards in § 1207.3.9. In short: obtain required permits, use listed components, keep the system within its original UL listing where applicable, perform commissioning, and document the work; previously used batteries (for example from EVs) are generally prohibited unless approved and refurbished in accordance with UL 1974 and approved by the fire code official. § 1207.3.7 § 1207.3.9
The single most important rule: get a construction permit, use listed components, commission and document the retrofit — and don’t reuse EV batteries unless the fire code official approves and the batteries were refurbished under UL 1974. § 1207.3.7 § 1207.3.9
Requirements in detail
Key retrofit steps (what you must do)
- Obtain a construction permit for the retrofit. § 1207.3.7(1)
- Use listed new batteries, battery modules, capacitors and similar ESS components. § 1207.3.7(2)
- Install and connect battery management and monitoring systems per the manufacturer’s instructions. § 1207.3.7(3)
- Maintain the system’s UL 9540 listing compliance where applicable — the overall installation must continue to comply with UL 9540 listing requirements after retrofit. § 1207.3.7(4)
- Commission retrofitted systems in accordance with the commissioning rules (see § 1207.2.1). § 1207.3.7(5)
- Record the retrofit work in the system service records log. § 1207.3.7(6)
When work is a “repair” vs. a “retrofit” vs. a “replacement”
- Repair (identical parts): Repair with identical parts is a repair (must be done by qualified personnel). § 1207.3.6
- Retrofit (non‑identical parts): Any work using other-than-identical parts is considered a retrofit and must comply with § 1207.3.7. § 1207.3.6 § 1207.3.7
- Replacement: Replacements of ESS are treated as new ESS installations and must comply with the full provisions of Chapter 12 applicable to new installations; the removed ESS must be decommissioned per § 1207.2.3. § 1207.3.8
Special rule for lead‑acid and nickel‑cadmium
- Swapping or retrofitting lead‑acid or nickel‑cadmium batteries with the same technology can be considered a repair (not a retrofit) when there is no increase in system size or energy capacity greater than 10 percent and the installation fits specified applications (communications utilities, certain utility substations/generating stations, or UL 1778 UPS standby power). § 1207.3.7.1
Reuse and repurposing (EV batteries and other previously used batteries)
- Storage batteries previously used in other applications (for example, electric vehicle propulsion) shall not be reused in Chapter 12 applications unless:
- approved by the fire code official, and
- refurbished by a battery refurbishing company approved in accordance with UL 1974. § 1207.3.9
- Note: UL 1974 is one of the referenced standards adopted in the code. UL 1974 is listed in the referenced-standards table.
Decision table — quick rules at a glance
| Decision question | Threshold / requirement | What it means for the project | Code reference |
|---|---|---|---|
| Is a permit required? | Construction permit required for retrofits | Apply for and obtain permit per local enforcement before starting work | § 1207.3.7(1) |
| Must new battery modules be listed? | Listed products only | Use listed batteries/modules/capacitors for retrofit | § 1207.3.7(2) |
| Are BMS/monitoring connections required? | Install per manufacturer instructions | Follow manufacturer wiring/installation for BMS | § 1207.3.7(3) |
| Does the system stay under UL 9540 listing? | Must continue to comply where applicable | Retain listing compliance after retrofit or evaluate changes | § 1207.3.7(4) |
| Is commissioning required? | Yes — retrofitted systems must be commissioned | Prepare and execute commissioning plan (see § 1207.2.1) | § 1207.3.7(5) |
| Documentation required? | Service records log entry required | Record retrofit details and tests in service log | § 1207.3.7(6) |
| Lead‑acid / Ni‑Cd swap treated as repair? | ≤ 10% increase in energy capacity AND specific applications | Considered repair (not retrofit) in listed applications | § 1207.3.7.1 |
| Can EV batteries be reused? | Only if approved by FCO and refurbished per UL 1974 | Generally prohibited unless refurbishment and FCO approval obtained | § 1207.3.9 |
| Replacement vs retrofit? | Replacements = new ESS installation | Full new-ESS compliance and decommissioning of old unit | § 1207.3.8 |
Exceptions & special cases
- The special repair rule for lead‑acid and nickel‑cadmium with ≤ 10 percent capacity increase applies only to the specific applications listed (communications utilities at < 50 VAC and 60 VDC; certain utility substation/generator control systems; UL 1778 UPS standby power). § 1207.3.7.1
- Existing ESS may retain their original signage if installed before current signage requirements—see signage exceptions under general provisions. (See related Sections in Chapter 12 for signage exceptions.)
- The fire code official has authority to approve deviations or reuse/repurpose cases (for example, approving an EV battery reuse after review). That approval is required for reused batteries under § 1207.3.9. § 1207.3.9
Common mistakes
- Assuming a parts swap is always a simple repair — if non‑identical parts are used it’s a retrofit and triggers § 1207.3.7 requirements. § 1207.3.6
- Failing to obtain a construction permit before starting retrofit work. § 1207.3.7(1)
- Installing used EV batteries without fire code official approval and without UL 1974 refurbisher documentation — this is prohibited. § 1207.3.9
- Neglecting commissioning after retrofit — retrofit systems must be commissioned per § 1207.2.1. § 1207.3.7(5)
Worked example — rooftop ESS retrofit with numbers
Scenario: A commercial building has an existing lithium‑ion UL 9540‑listed rooftop ESS rated 400 kWh. The owner wants to replace battery modules with higher‑capacity modules so the system capacity becomes 440 kWh (a 10% increase).
Apply the rules:
- Is this a repair, retrofit or replacement? Replacing modules with non‑identical parts = retrofit. § 1207.3.6
- Permit: Must obtain a construction permit before starting. § 1207.3.7(1)
- Listings: New modules must be listed. If the change affects the system’s UL 9540 listing, the installation must continue to comply with UL 9540; confirm with manufacturer/listing documentation. § 1207.3.7(2,4)
- Commissioning: Because capacity changed and modules are non‑identical, commissioning per § 1207.2.1 is required before returning the system to service. § 1207.3.7(5)
- Documentation: Record the retrofit work in the service records log. § 1207.3.7(6)
Note: If the new capacity had been greater than 10% and the batteries were lead‑acid or Ni‑Cd, the work could not be treated as repair under § 1207.3.7.1; and for other chemistries (like lithium‑ion) the 10% rule does not make it a “repair” — it remains a retrofit and must follow full retrofit requirements. § 1207.3.7.1
Related provisions
- § 1207.2.1 — Commissioning requirements for newly installed and retrofitted ESS.
- § 1207.2.3 — Decommissioning requirements (applies when replacing ESS).
- § 1207.3.6 — Repairs and the distinction between repairs and retrofits.
- § 1207.3.8 — Replacements are treated as new ESS installations.
- § 1207.4 (and subsections) — General installation, signage, ventilation, and working clearances that apply after retrofit.
- § 1207.3.9 — Reused and repurposed equipment; UL 1974 refurbishing requirement.
- Referenced standard: UL 1974 — battery refurbishing standard adopted as a referenced standard.
Code references
Grounded in the retrieved California Fire Code — click a citation to read the verbatim passage:
CFC § 1207.3.7 High relevance — show source text
1207.3.7 Retrofits. Retrofitting of an existing ESS shall comply with the following:
- A construction permit shall be obtained in accordance with Section 105.6.6.
- New batteries, battery modules, capacitors and similar ESS components shall be listed.
- Battery management and other monitoring systems shall be connected and installed in accordance with the manufacturer’s instructions.
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- The overall installation shall continue to comply with UL 9540 listing requirements, where applicable.
- Systems that have been retrofitted shall be commissioned in accordance with Section 1207.2.1.
- Retrofits shall be documented in the service records log. (Material based on NFPA 855 2023 Ed.)
1207.3.7.1 Retrofitting lead acid and nickel cadmium. Changing out or retrofitting of lead-acid and nickel-cadmium batteries with other lead-acid and nickel-cadmium batteries in the following applications shall be considered repairs where there is no increase in system size or energy capacity greater than 10 percent of the original design.
At facilities under the exclusive control of communications utilities that comply with NFPA 76 and operate at less than 50 VAC and 60 VDC.
Battery systems used for DC power for control of substations and control or safe shutdown of generating stations under the exclusive control of the electric utility, and located outdoors or in building spaces used exclusively for such installations.
Batteries in uninterruptible power supplies listed and labeled in accordance with UL 1778 and used for standby power applications only.
(Material based on NFPA 855 2023 Ed.)
1207.3.8 Replacements. Replacements of ESS shall be considered new ESS installations and shall comply with the provisions of Section 1207 as applicable to new ESS. The ESS being replaced shall be decommissioned in accordance with Section 1207.2.3. (Material based on NFPA 855 2023 Ed.)
1207.3.9 Reused and repurposed equipment. Equipment and materials shall only be reused or reinstalled as permitted in Section 104.9.1. Storage batteries previously used in other applications, such as electric vehicle propulsion, shall not be reused in applications regulated by Chapter 12 unless approved by the fire code official and unless the equipment is refurbished by a battery refurbishing company approved in accordance with UL 1974. (Material based on NFPA 855 2023 Ed.)
1207.4 General installations requirements. Stationary and mobile ESS shall comply with the requirements of Sections 1207.4.1 through 1207.4.12.
1207.4.1 Electrical disconnects. Where the ESS disconnecting means is not within sight of the main electrical service disconnecting means, placards or directories shall be installed at the location of the main electrical service disconnecting means indicating the location of stationary storage battery system disconnecting means in accordance with the California Electrical Code .
Exception: Electrical disconnects for lead-acid and nickel-cadmium battery systems at facilities under the exclusive control of communications utilities and operating at less than 50 VAC and 60 VDC shall be permitted to have electrical disconnects signage in accordance with NFPA 76.
CFC § 1207.3.2 High relevance — show source text
(Material based on NFPA 855 2023 Ed.)
1207.3.2 Equipment listing. Chargers, inverters and energy storage management systems shall be covered as part of the UL 9540 listing or shall be listed separately.
1207.3.3 Utility interactive systems. Inverters shall be listed and labeled in accordance with UL 1741. Only inverters listed and labeled for utility interactive system use and identified as interactive shall be allowed to operate in parallel with the electric utility power system to supply power to common loads.
1207.3.4 Energy storage management system. Where required by the ESS listing, an approved energy storage management system that monitors and balances cell voltages, currents and temperatures within the manufacturer’s specifications shall be provided. The system shall disconnect electrical connections to the ESS or otherwise place it in a safe condition if potentially hazardous temperatures or other conditions such as short circuits, over voltage or under voltage are detected. (Material based on NFPA 855 2023 Ed.)
1207.3.5 Enclosures. Enclosures of ESS shall be of noncombustible construction. (Material based on NFPA 855 2023 Ed.)
1207.3.6 Repairs. Repairs of ESS shall only be done by qualified personnel. Repairs with other than identical parts shall be considered retrofitting and comply with Section 1207.3.7. Repairs shall be documented in the service records log. (Material based on NFPA 855 2023 Ed.)
1207.3.7 Retrofits. Retrofitting of an existing ESS shall comply with the following:
- A construction permit shall be obtained in accordance with Section 105.6.6.
- New batteries, battery modules, capacitors and similar ESS components shall be listed.
- Battery management and other monitoring systems shall be connected and installed in accordance with the manufacturer’s instructions.
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- The overall installation shall continue to comply with UL 9540 listing requirements, where applicable.
- Systems that have been retrofitted shall be commissioned in accordance with Section 1207.2.1.
- Retrofits shall be documented in the service records log. (Material based on NFPA 855 2023 Ed.)
1207.3.7.1 Retrofitting lead acid and nickel cadmium. Changing out or retrofitting of lead-acid and nickel-cadmium batteries with other lead-acid and nickel-cadmium batteries in the following applications shall be considered repairs where there is no increase in system size or energy capacity greater than 10 percent of the original design.
At facilities under the exclusive control of communications utilities that comply with NFPA 76 and operate at less than 50 VAC and 60 VDC.
Battery systems used for DC power for control of substations and control or safe shutdown of generating stations under the exclusive control of the electric utility, and located outdoors or in building spaces used exclusively for such installations.
Batteries in uninterruptible power supplies listed and labeled in accordance with UL 1778 and used for standby power applications only.
(Material based on NFPA 855 2023 Ed.)
CFC § 1207.4.10 High relevance — show source text
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shall not inhibit the required air flow to or exhaust from the electrochemical ESS and its components. (Material based on NFPA 855 2023 Ed.)
1207.4.10 Occupied work centers. Electrochemical ESS located in rooms or areas occupied by personnel not directly involved with maintenance, service and testing of the systems shall comply with the following:
- Electrochemical ESS located in occupied work centers shall be housed in locked noncombustible cabinets or other enclosures to prevent access by unauthorized personnel.
- Where electrochemical ESS are contained in cabinets in occupied work centers, the cabinets shall be located within 10 feet (3048 mm) of the equipment that they support.
- Cabinets shall include signage complying with Section 1207.4.8. (Material based on NFPA 855 2023 Ed.)
1207.4.11 Open rack installations. Where electrochemical ESS are installed in a separate equipment room and only authorized personnel have access to the room, they shall be permitted to be installed on an open rack for ease of maintenance. (Material based on NFPA 855 2023 Ed.)
1207.4.12 Walk-in units. Walk-in units shall be entered only for inspection, maintenance and repair of ESS units and ancillary equipment, and shall not be occupied for other purposes.
1207.5 Electrochemical ESS protection. The protection of electrochemical ESS shall be in accordance with Sections 1207.5.1 through 1207.5.8 where required by Sections 1207.7 through 1207.10. (Material based on NFPA 855 2023 Ed.)
TABLE 1207.5—MAXIMUM ALLOWABLE QUANTITIES OF ELECTROCHEMICAL ESS Col2 TECHNOLOGY MAXIMUM ALLOWABLE QUANTITIESa STORAGE BATTERIES STORAGE BATTERIES Flow batteriesb 600 kWh Lead-acid, all types Unlimited Lithium-ion 600 kWh Nickel-cadmium (Ni-Cd), nickel-metal hydride (NI-MH) and nickel zinc (Ni-Zn) Unlimited Sodium nickel chloride 600 kWh Zinc-manganese dioxide (Zn-MnO2) Unlimited Other battery technologies 200 kWh CAPACITORS CAPACITORS All types 20 kWh OTHER ELECTROCHEMICAL ESS OTHER ELECTROCHEMICAL ESS All types 20 kWh For SI: 1 kilowatt hour = 3.6 megajoules.
a. For electrochemical ESS units rated in amp-hours, kWh shall equal rated voltage times the amp-hour rating divided by 1,000.
b. Shall include vanadium, zinc-bromine, polysulfide-bromide and other flowing electrolyte-type technologies.For SI: 1 kilowatt hour = 3.6 megajoules.
a. For electrochemical ESS units rated in amp-hours, kWh shall equal rated voltage times the amp-hour rating divided by 1,000.
b. Shall include vanadium, zinc-bromine, polysulfide-bromide and other flowing electrolyte-type technologies.CFC § 1207.3.8 High relevance — show source text
(Material based on NFPA 855 2023 Ed.)
1207.3.8 Replacements. Replacements of ESS shall be considered new ESS installations and shall comply with the provisions of Section 1207 as applicable to new ESS. The ESS being replaced shall be decommissioned in accordance with Section 1207.2.3. (Material based on NFPA 855 2023 Ed.)
1207.3.9 Reused and repurposed equipment. Equipment and materials shall only be reused or reinstalled as permitted in Section 104.9.1. Storage batteries previously used in other applications, such as electric vehicle propulsion, shall not be reused in applications regulated by Chapter 12 unless approved by the fire code official and unless the equipment is refurbished by a battery refurbishing company approved in accordance with UL 1974. (Material based on NFPA 855 2023 Ed.)
1207.4 General installations requirements. Stationary and mobile ESS shall comply with the requirements of Sections 1207.4.1 through 1207.4.12.
1207.4.1 Electrical disconnects. Where the ESS disconnecting means is not within sight of the main electrical service disconnecting means, placards or directories shall be installed at the location of the main electrical service disconnecting means indicating the location of stationary storage battery system disconnecting means in accordance with the California Electrical Code .
Exception: Electrical disconnects for lead-acid and nickel-cadmium battery systems at facilities under the exclusive control of communications utilities and operating at less than 50 VAC and 60 VDC shall be permitted to have electrical disconnects signage in accordance with NFPA 76.
1207.4.2 Working clearances. Access and working space shall be provided and maintained about all electrical equipment to permit ready and safe operation and maintenance of such equipment in accordance with the California Electrical Code and the manufacturer’s instructions.
1207.4.3 Fire-resistance-rated separations. Rooms and other indoor areas containing ESS shall be separated from other areas of the building in accordance with Section 1207.7.4. ESS shall be permitted to be in the same room with the equipment they support.
1207.4.4 Seismic and structural design. Stationary ESS shall comply with the seismic design requirements in Chapter 16 of the California Building Code, and shall not exceed the floor loading limitation of the building.
1207.4.5 Vehicle impact protection. Where ESS are subject to impact by a motor vehicle, including forklifts, vehicle impact protection shall be provided in accordance with Section 312.
1207.4.6 Combustible storage. Combustible materials shall not be stored in ESS rooms, areas or walk-in units. Combustible materials in occupied work centers covered by Section 1207.4.10 shall be stored at least 3 feet (914 mm) from ESS cabinets.
1207.4.7 Toxic and highly toxic gases. ESS that have the potential to release toxic and highly toxic gas during charging, discharging and normal use conditions shall be provided with a hazardous exhaust system in accordance with Chapter 5 of the California Mechanical Code .
CFC § 1207.8.1. High relevance — show source text
See Section 1207.8.1.
b. See Section 1207.8.2.
c. Where approved by the fire code official, fire suppression systems are permitted to be omitted.
d. In outdoor walk-in units, spacing is not required between ESS units and the walls of the enclosure.|a. See Section 1207.8.1.
b. See Section 1207.8.2.
c. Where approved by the fire code official, fire suppression systems are permitted to be omitted.
d. In outdoor walk-in units, spacing is not required between ESS units and the walls of the enclosure.|a. See Section 1207.8.1.
b. See Section 1207.8.2.
c. Where approved by the fire code official, fire suppression systems are permitted to be omitted.
d. In outdoor walk-in units, spacing is not required between ESS units and the walls of the enclosure.|a. See Section 1207.8.1.
b. See Section 1207.8.2.
c. Where approved by the fire code official, fire suppression systems are permitted to be omitted.
d. In outdoor walk-in units, spacing is not required between ESS units and the walls of the enclosure.|1207.8.1 Remote outdoor installations. For the purpose of Table 1207.8, remote outdoor installations include ESS located more than 100 feet (30 480 mm) from buildings, lot lines, public ways, stored combustible materials, hazardous materials, high-piled stock and other exposure hazards. (Material based on NFPA 855 2023 Ed.)
1207.8.2 Installations near exposures. For the purpose of Table 1207.8, installations near exposures include all outdoor ESS installations that do not comply with Section 1207.8.1 remote outdoor location requirements. (Material based on NFPA 855 2023 Ed.)
1207.8.3 Clearance to exposures. ESS located outdoors shall be separated by a minimum of 10 feet (3048 mm) from the following exposures:
Lot lines.
Public ways.
Buildings.
Stored combustible materials.
Hazardous materials.
High-piled stock.
Other exposure hazards.
Exceptions: (Material based on NFPA 855 2023 Ed.)
Clearances are permitted to be reduced to 3 feet (914 mm) where a 1-hour free-standing fire barrier suitable for exterior use and extending 5 feet (1524 mm) above and 5 feet (1524 mm) beyond the physical boundary of the ESS installation is provided to protect the exposure.
Clearances to buildings are permitted to be reduced to 3 feet (914 mm) where noncombustible exterior walls with no openings or combustible overhangs are provided on the wall adjacent to the ESS and the fire-resistance rating of the exterior wall is a minimum of 2 hours.
Clearances to buildings are permitted to be reduced to 3 feet (914 mm) where a weatherproof enclosure constructed of noncombustible materials is provided over the ESS, and it has been demonstrated that a fire within the enclosure will not ignite combustible materials outside the enclosure based on large-scale fire testing complying with Section 1207.1.7.
CFC § 1207.4.2 High relevance — show source text
1207.4.2 Working clearances. Access and working space shall be provided and maintained about all electrical equipment to permit ready and safe operation and maintenance of such equipment in accordance with the California Electrical Code and the manufacturer’s instructions.
1207.4.3 Fire-resistance-rated separations. Rooms and other indoor areas containing ESS shall be separated from other areas of the building in accordance with Section 1207.7.4. ESS shall be permitted to be in the same room with the equipment they support.
1207.4.4 Seismic and structural design. Stationary ESS shall comply with the seismic design requirements in Chapter 16 of the California Building Code, and shall not exceed the floor loading limitation of the building.
1207.4.5 Vehicle impact protection. Where ESS are subject to impact by a motor vehicle, including forklifts, vehicle impact protection shall be provided in accordance with Section 312.
1207.4.6 Combustible storage. Combustible materials shall not be stored in ESS rooms, areas or walk-in units. Combustible materials in occupied work centers covered by Section 1207.4.10 shall be stored at least 3 feet (914 mm) from ESS cabinets.
1207.4.7 Toxic and highly toxic gases. ESS that have the potential to release toxic and highly toxic gas during charging, discharging and normal use conditions shall be provided with a hazardous exhaust system in accordance with Chapter 5 of the California Mechanical Code .
1207.4.8 Signage. Approved signs shall be provided on or adjacent to all entry doors for ESS rooms or areas and on enclosures of ESS cabinets and walk-in units located outdoors, on rooftops or in open parking garages. Signs designed to meet both the requirements of this section and the California Electrical Code shall be permitted. The signage shall include the following or equivalent:
“ENERGY STORAGE SYSTEM,” “BATTERY STORAGE SYSTEM,” “CAPACITOR ENERGY STORAGE SYSTEM” or the equivalent.
The identification of the electrochemical ESS technology present.
“ENERGIZED ELECTRICAL CIRCUITS.”
Where water-reactive electrochemical ESS are present, the signage shall include “APPLY NO WATER.”
Current contact information, including phone number, for personnel authorized to service the equipment and for fire mitigation personnel required by Section 1207.1.8.1.
Exception: Existing electrochemical ESS shall be permitted to include the signage required at the time they were installed. (Material based on NFPA 855 2023 Ed.)
1207.4.9 Security of installations. Rooms, areas and walk-in units in which electrochemical ESS are located shall be secured against unauthorized entry and safeguarded in an approved manner. Security barriers, fences, landscaping and other enclosures
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shall not inhibit the required air flow to or exhaust from the electrochemical ESS and its components. (Material based on NFPA 855 2023 Ed.)
CFC § 12-10 High relevance — show source text
Shall include vanadium, zinc-bromine, polysulfide-bromide and other flowing electrolyte-type technologies.
c. Fifty gallons of lead-acid battery electrolyte shall be considered equivalent to 70 kWh.
d. Covers nonelectrochemical technologies such as flywheel and thermal ESS.|12-10 2025 CALIFORNIA FIRE CODE
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1207.1.4 Permits. Permits shall be obtained for ESS as follows:
- Construction permits shall be obtained for stationary ESS installations and for mobile ESS charging and storage installations covered by Section 1207.10.1. Permits shall be obtained in accordance with Section 105.6.6.
- Operational permits shall be obtained for stationary ESS installations and for mobile ESS deployment operations covered by Section 1207.10.3. Permits shall be obtained in accordance with Section 105.5.14.
1207.1.4.1 Communication utilities. Operational permits shall not be required for lead-acid and nickel-cadmium battery systems at facilities under the exclusive control of communications utilities that comply with NFPA 76 and operate at less than 50 voltage alternating current (VAC) and 60 voltage direct current (VDC).
1207.1.5 Construction documents. The following information shall be provided with the permit application:
- Location and layout diagram of the room or area in which the ESS is to be installed.
- Details on the hourly fire-resistance ratings of assemblies enclosing the ESS.
- The quantities and types of ESS to be installed.
- Manufacturer’s specifications, ratings and listings of each ESS.
- Description of energy (battery) management systems and their operation.
- Location and content of required signage.
- Details on fire suppression, smoke or fire detection, thermal management, ventilation, exhaust and deflagration venting systems, if provided.
- Support arrangement associated with the installation, including any required seismic restraint.
- A commissioning plan complying with Section 1207.2.1.
- A decommissioning plan complying with Section 1207.2.3.
- A fire safety and evacuation plan in accordance with Section 404.
1207.1.5.1 Utilities applicability. Plans and specifications associated with ESS owned and operated by electric utilities as a component of the electric grid that are considered critical infrastructure documents in accordance with the provisions of the North American Electric Reliability Corporation and other applicable governmental laws and regulations shall be made available to the fire code official for viewing based on the requirements of the applicable governmental laws and regulations. (Material based on NFPA 855 2023 Ed.)
1207.1.6 Hazard mitigation analysis. A failure modes and effects analysis (FMEA) or other approved hazard mitigation analysis shall be provided in accordance with Section 104.2.2 under any of the following conditions:
- Where ESS technologies not specifically identified in Table 1207.1.3 are provided.
- More than one ESS technology is provided in a single fire area where there is a potential for adverse interaction between technologies.
- Where allowed as a basis for increasing maximum allowable quantities. See Section 1207.5.2.
- Where required by the fire code official to address a potential hazard with an ESS installation that is not addressed by existing requirements.
CFC § 1207.7.2 High relevance — show source text
1207.7.2 Nondedicated-use buildings. For the purpose of Table 1207.7, nondedicated-use buildings include all buildings that contain ESS and do not comply with Section 1207.7.1 dedicated-use building requirements. (Material based on NFPA 855 2023 Ed.)
1207.7.3 Dwelling units and sleeping units. ESS shall not be installed in sleeping units or in habitable spaces of dwelling units. (Material based on NFPA 855 2023 Ed.)
1207.7.4 Fire-resistance-rated separations. Rooms and areas containing ESS shall include fire-resistance-rated separations as follows:
- In dedicated-use buildings, rooms and areas containing ESS shall be separated from areas in which administrative and support personnel are located.
- In nondedicated-use buildings, rooms and areas containing ESS shall be separated from other areas in the building.
Separation shall be provided by 2-hour fire barriers constructed in accordance with Section 707 of the California Building Code and 2-hour horizontal assemblies constructed in accordance with Section 711 of the California Building Code, as appropriate. (Material based on NFPA 855 2023 Ed.)
1207.8 Outdoor installations. Outdoor installations shall be in accordance with Sections 1207.8.1 through 1207.8.3. Exterior wall installations for individual ESS units not exceeding 20 kWh shall be in accordance with Section 1207.8.4. (Material based on NFPA 855 2023 Ed.)
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TABLE 1207.8—OUTDOOR ESS INSTALLATIONSa Col2 Col3 Col4 COMPLIANCE REQUIRED COMPLIANCE REQUIRED REMOTE INSTALLATIONSa INSTALLATIONS NEAR EXPOSURESb Feature Section Section Section All ESS installations 1207.4 Yes Yes Clearance to exposures 1207.8.3 Yes Yes Fire suppression systems 1207.5.5 Yesc Yes Maximum allowable quantities 1207.5.2 No Yes Maximum enclosure size 1207.5.6 Yes Yes Means of egress separation 1207.5.8 Yes Yes Size and separation 1207.5.1 No Yesd Smoke and automatic fire detection 1207.5.4 Yes Yes Technology-specific protection 1207.6 Yes Yes Vegetation control 1207.5.7 Yes Yes a. See Section 1207.8.1.
b. See Section 1207.8.2.
c. Where approved by the fire code official, fire suppression systems are permitted to be omitted.
d. In outdoor walk-in units, spacing is not required between ESS units and the walls of the enclosure.a. See Section 1207.8.1.
b. See Section 1207.8.2.
c. Where approved by the fire code official, fire suppression systems are permitted to be omitted.
d. In outdoor walk-in units, spacing is not required between ESS units and the walls of the enclosure.a. CFC § 1207.4.8 High relevance — show source text
1207.4.8 Signage. Approved signs shall be provided on or adjacent to all entry doors for ESS rooms or areas and on enclosures of ESS cabinets and walk-in units located outdoors, on rooftops or in open parking garages. Signs designed to meet both the requirements of this section and the California Electrical Code shall be permitted. The signage shall include the following or equivalent:
“ENERGY STORAGE SYSTEM,” “BATTERY STORAGE SYSTEM,” “CAPACITOR ENERGY STORAGE SYSTEM” or the equivalent.
The identification of the electrochemical ESS technology present.
“ENERGIZED ELECTRICAL CIRCUITS.”
Where water-reactive electrochemical ESS are present, the signage shall include “APPLY NO WATER.”
Current contact information, including phone number, for personnel authorized to service the equipment and for fire mitigation personnel required by Section 1207.1.8.1.
Exception: Existing electrochemical ESS shall be permitted to include the signage required at the time they were installed. (Material based on NFPA 855 2023 Ed.)
1207.4.9 Security of installations. Rooms, areas and walk-in units in which electrochemical ESS are located shall be secured against unauthorized entry and safeguarded in an approved manner. Security barriers, fences, landscaping and other enclosures
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shall not inhibit the required air flow to or exhaust from the electrochemical ESS and its components. (Material based on NFPA 855 2023 Ed.)
1207.4.10 Occupied work centers. Electrochemical ESS located in rooms or areas occupied by personnel not directly involved with maintenance, service and testing of the systems shall comply with the following:
- Electrochemical ESS located in occupied work centers shall be housed in locked noncombustible cabinets or other enclosures to prevent access by unauthorized personnel.
- Where electrochemical ESS are contained in cabinets in occupied work centers, the cabinets shall be located within 10 feet (3048 mm) of the equipment that they support.
- Cabinets shall include signage complying with Section 1207.4.8. (Material based on NFPA 855 2023 Ed.)
1207.4.11 Open rack installations. Where electrochemical ESS are installed in a separate equipment room and only authorized personnel have access to the room, they shall be permitted to be installed on an open rack for ease of maintenance. (Material based on NFPA 855 2023 Ed.)
1207.4.12 Walk-in units. Walk-in units shall be entered only for inspection, maintenance and repair of ESS units and ancillary equipment, and shall not be occupied for other purposes.
1207.5 Electrochemical ESS protection. The protection of electrochemical ESS shall be in accordance with Sections 1207.5.1 through 1207.5.8 where required by Sections 1207.7 through 1207.10. (Material based on NFPA 855 2023 Ed.)
CFC § 304.8 High relevance — show source text
a_| |In detached garages and detached accessory structures|200|| |In detached garages and detached accessory structures|600|Detached garage or detached accessory structure is
a minimum 10 feet away from property lines and
dwellings.| |Outdoors on the ground|200|ESS is a minimum 3 feet away from property lines
and dwellings.| |Outdoors on the ground|600|ESS is a minimum 10 feet away from property lines
and dwellings.| |For SI: 1 foot = 304.8 mm
a. Noncombustible wall surface shall extend in accordance with all the following:
1. A minimum of 5 feet horizontally from the edge of the ESS.
2. A minimum of 1 foot vertically below the bottom edge of the ESS.
3. A minimum of 8 feet vertically above the ESS, or to a noncombustible eave, whichever is less.
The code official is authorized to approve reductions of installation requirements based on large-scale fire testing complying with Section 1207.1.5.|For SI: 1 foot = 304.8 mm
a. Noncombustible wall surface shall extend in accordance with all the following:
1. A minimum of 5 feet horizontally from the edge of the ESS.
2. A minimum of 1 foot vertically below the bottom edge of the ESS.
3. A minimum of 8 feet vertically above the ESS, or to a noncombustible eave, whichever is less.
The code official is authorized to approve reductions of installation requirements based on large-scale fire testing complying with Section 1207.1.5.|For SI: 1 foot = 304.8 mm
a. Noncombustible wall surface shall extend in accordance with all the following:
1. A minimum of 5 feet horizontally from the edge of the ESS.
2. A minimum of 1 foot vertically below the bottom edge of the ESS.
3. A minimum of 8 feet vertically above the ESS, or to a noncombustible eave, whichever is less.
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1207.11.5 Electrical installation. ESS shall be installed in accordance with the California Electrical Code. Inverters shall be listed and labeled in accordance with UL 1741 or provided as part of the UL 9540 listing. Systems connected to the utility grid shall use inverters listed for utility interaction. (Material based on NFPA 855 2023 Ed.)
1207.11.6 Fire detection. ESS installed in Group R-3 and R-4 occupancies shall comply with the following:
- Rooms and areas within dwelling units, sleeping units, basements and attached garages in which ESS are installed shall be protected by smoke alarms in accordance with Section 907.2.11.
- A listed heat alarm shall be installed in locations where smoke alarms cannot be installed based on their listing.
CFC § 12-11 Medium relevance — show source text
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1207.1.8 Fire remediation. Where a fire or other event has damaged the ESS and ignition or re-ignition of the ESS is possible, the system owner, agent or lessee shall take the following actions, at their expense, to mitigate the hazard or remove damaged equipment from the premises to a safe location.
1207.1.8.1 Fire mitigation personnel. Where, in the opinion of the fire code official, it is essential for public safety that trained personnel be on-site to respond to possible ignition or re-ignition of a damaged ESS, the system owner, agent or lessee shall dispatch within 15 minutes one or more fire mitigation personnel to the premise, as required and approved, at their expense. These personnel shall remain on duty continuously after the fire department leaves the premise until the damaged energy storage equipment is removed from the premises, or earlier if the fire code official indicates the public safety hazard has been abated. (Material based on NFPA 855 2023 Ed.)
1207.1.8.2 Duties. On-duty fire mitigation personnel shall have the following responsibilities:
Keep a diligent watch for fires, obstructions to means of egress and other hazards.
Immediately contact the fire department if their assistance is needed to mitigate any hazards or extinguish fires.
Take prompt measures for remediation of hazards in accordance with the decommissioning plan per Section 1207.2.3.
Take prompt measures to assist in the evacuation of the public from the structures. (Material based on NFPA 855 2023 Ed.)
1207.2 Commissioning, decommissioning, operation and maintenance. Commissioning, decommissioning, operation and maintenance shall be conducted in accordance with this section.
1207.2.1 Commissioning. Commissioning of newly installed ESS and existing ESS that have been retrofitted, replaced or previously decommissioned and are returning to service shall be conducted prior to the ESS being placed in service in accordance with a commissioning plan that has been approved prior to initiating commissioning. The commissioning plan shall include the following:
- A narrative description of the activities that will be accomplished during each phase of commissioning, including the personnel intended to accomplish each of the activities.
- A listing of the specific ESS and associated components, controls and safety-related devices to be tested, a description of the tests to be performed and the functions to be tested.
- Conditions under which all testing will be performed, which are representative of the conditions during normal operation of the system.
- Documentation of the owner’s project requirements and the basis of design necessary to understand the installation and operation of the ESS.
- Verification that required equipment and systems are installed in accordance with the approved plans and specifications.
- Integrated testing for all fire and safety systems.
- Testing for any required thermal management, ventilation or exhaust systems associated with the ESS installation.
- Preparation and delivery of operation and maintenance documentation.
- Training of facility operating and maintenance staff.
- Identification and documentation of the requirements for maintaining system performance to meet the original design intent during the operation phase.
- Identification and documentation of personnel who are qualified to service, maintain and decommission the ESS, and respond to incidents involving the ESS, including documentation that such service has been contracted for./p>
CFC § 722.5.2 Medium relevance — show source text
FIGURE 722.5.2—DETERMINATION OF THE HEATED PERIMETER OF STRUCTURAL STEEL BEAMS AND GIRDERS
722.5.2.1 Determination of fire resistance. These procedures establish a basis for determining resistance of structural steel beams and girders that differ in size from that specified in approved fire-resistance-rated assemblies as a function of the thickness of fire-resistant material and the weight ( W) and heated perimeter (D) of the beam or girder. As used in these sections, W is the average weight of a structural steel element in pounds per linear foot (plf). The heated perimeter, D, is the inside perimeter of the fire-resistant material in inches as illustrated in Figure 722.5.2.
722.5.2.1.1 Weight-to-heated perimeter. The weight-to-heated-perimeter ratios (W/D), for both contour and box fire-resistant protection profiles, for the wide flange shapes most often used as beams or girders are given in Table 722.5.1(4). For different shapes, the weight-to-heated-perimeter ratios (W/D) shall be determined in accordance with the definitions given in this section.
722.5.2.1.2 Beam and girder substitutions. Except as provided for in Section 722.5.2.2, structural steel beams in approved fire-resistance-rated assemblies shall be considered to be the minimum permissible size. Other beam or girder shapes shall be permitted to be substituted provided that the weight-to-heated-perimeter ratio (W/D) of the substitute beam is equal to or greater than that of the beam specified in the approved assembly.
722.5.2.2 Sprayed fire-resistive materials (SFRM). The provisions in this section apply to structural steel beams and girders protected with sprayed fire-resistive materials ( SFRM ). Larger or smaller beam and girder shapes shall be permitted to be substituted for beams specified in approved unrestrained or restrained fire-resistance-rated assemblies, provided that the thickness of the SFRM is adjusted in accordance with the following expression:
Equation 7-17 h 2 = h 1 [( W 1 / D 1 ) + 0.60] / [( W 2 / D 2 ) + 0.60]
where:
h = Thickness of SFRM in inches.
W = Weight of the structural steel beam or girder in pounds per linear foot.
D = Heated perimeter of the structural steel beam in inches.
Subscript 1 refers to the beam and SFRM thickness in the approved assembly.
Subscript 2 refers to the substitute beam or girder and the required thickness of SFRM .
The fire resistance of structural steel beams and girders protected with intumescent fire-resistive materials shall be determined on the basis of fire-resistance tests in accordance with Section 703.2.
722.5.2.2.1 Minimum thickness. The use of Equation 7-17 is subject to the following conditions:
- The weight-to-heated-perimeter ratio for the substitute beam or girder (W 2 /D 2 ) shall be not less than 0.37.
- The thickness of fire protection materials calculated for the substitute beam or girder (T 1 ) shall be not less than [3] / 8 inch (9.5 mm).
Frequently asked questions
Can I swap modules with a different brand without a permit?
No. Swapping non‑identical parts is treated as a retrofit, which requires a construction permit and compliance with the items listed in § 1207.3.7. § 1207.3.7
Are second‑life EV batteries automatically allowed if refurbished?
No. Previously used batteries (for example from EVs) shall not be reused unless the fire code official approves the reuse and the batteries were refurbished by a refurbisher approved under UL 1974. § 1207.3.9
If I replace an ESS completely, do retrofit rules apply?
No. A full replacement of an ESS is considered a new ESS installation and must comply with the new‑installation provisions in Chapter 12; the old ESS must be decommissioned per § 1207.2.3. § 1207.3.8
What triggers commissioning after work on an ESS?
Any retrofitted system, and any existing ESS returning to service after replacement or decommissioning, must be commissioned according to the approved commissioning plan in § 1207.2.1. § 1207.3.7(5)
Is there a small tolerance where swapping lead‑acid cells is easier?
Yes — for certain lead‑acid and nickel‑cadmium applications, swapping to the same battery type is considered a repair (not retrofit) if there is no increase in system size or energy capacity greater than 10% and the installation meets the specific application conditions in § 1207.3.7.1. § 1207.3.7.1
More in California Fire Code
- Administration and Definitions
- General Requirements and Emergency Planning
- Fire Service Features and Fire Department Access
- Referenced Standards and Adoptable Appendices (Chapter 80; Appendices A–Q)
- Fire and Smoke Protection Features (fire‑resistance, barriers)
- Interior Finish, Decorative Materials and Furnishings
- Fire Protection and Life‑Safety Systems (sprinklers, alarms, smoke control)
- Means of Egress (exit design and maintenance)
- Construction Requirements for Existing Buildings (retrofit rules)
- Energy Systems and Stationary Energy Storage (ESS)
- Special Occupancies and Operations (chapters 20–41, 48–49)
- Hazardous Materials — Storage, Use and Handling (Chapters 50–67)
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