C&I Battery Storage RFQ Checklist: What to Specify So Quotes Are Comparable

Ask five suppliers for “a 200 kWh battery cabinet” and you will get five quotes that can’t be compared. One includes the PCS, another doesn’t. One assumes a single cycle a day, another two. One quotes the cabinet only, another includes fire detection, commissioning and spares. A C&I battery storage RFQ works when every supplier answers the same questions. This checklist sets out those questions, starting with the parts of a project that fail most often.

General information as of 30 October 2026, not engineering, legal or fire-protection advice. Codes are adopted and amended locally. The authority having jurisdiction (AHJ) and your grid operator decide what applies to your site.

Short answer

• Define the job first: the use case, power (kW), energy (kWh), cycles per day and site constraints.
• Make integration part of the RFQ: PCS, grid connection, EMS and communications, thermal management and fire protection. These are where projects most often go wrong.
• Ask every supplier for the same documents and the same scope, using the checklist table below.
• Ask about commercial terms such as warranty, spares and lead time, and get the answers in writing. Don’t assume them from a brochure.

Why C&I battery projects fail: integration, not just cells

In a May 2024 white paper, EPRI analysed its BESS Failure Incident Database. At the time of writing the database held 81 incidents, and 26 of them had enough information to assign a root cause. EPRI found that:

• “Integration, Assembly & Construction was the most common root cause of failure in this analysis.”
• Balance-of-system components and controls accounted for the vast majority of failed elements. “Only 3 incidents, or 11% of classified incidents, are attributed directly to the cells.”
• “The majority (72%) of failures where the system age is known happen during construction, commissioning, or within the first two years of operation.”

EPRI’s report defines balance of system as everything except cells, modules and controls, such as busbars, cabling, enclosures, power conversion systems, transformers, fire suppression, HVAC and liquid cooling. EPRI also notes that the global grid-scale BESS failure rate fell 97% between 2018 and 2023. So an RFQ that asks only about cell grade and cycle life misses the parts of the system where most of the risk sits.

Section 1: use case and sizing

• Use case: peak shaving, backup, PV self-consumption, time-of-use shifting, or a mix. Say which has priority.
• Power and energy: the kW the system must deliver, for how long, and the usable kWh you need at the point of connection.
• Cycles: expected cycles per day and operating hours, which drive the duty cycle the supplier quotes against.
• Site: indoor or outdoor, footprint, climate range, altitude, access for delivery and cranes, and distance to buildings and property lines.
• Growth: whether you expect to add capacity later, and how.

Section 2: electrical integration

• PCS or inverter: the brand and model if you already have one, or ask the supplier to propose a PCS. Make clear who is responsible for battery-PCS compatibility.
• Grid connection: the voltage, the connection point and the grid code or utility requirements you must meet.
• EMS and communications: which system controls dispatch, and the protocol and interface you need, such as Modbus or CAN. The supplier should confirm what the offered system actually supports for your setup, in writing. Our BMS CAN protocol guide explains what to specify.
• System voltage: low-voltage 51.2V-class racks or a high-voltage stack. See our high-voltage vs low-voltage storage guide.
• Start-up and protection: pre-charge, fusing and short-circuit current. See our inverter pre-charge and BMS trip guide.

Section 3: fire safety and codes

Which fire and building codes apply, and which edition, depends on where the site is. Ask your AHJ early, because the answer can change the enclosure, spacing, detection and suppression in the quote. In your RFQ:

• Ask for UL 9540A data for the offered system, or say that you need it. UL describes UL 9540A as the American and Canadian national standard for assessing fire propagation from thermal runaway in battery energy storage systems. UL says the 6th edition, published on 13 March 2026, adds an installation-level large-scale fire test after the module-level test, and no longer requires the unit-level test for non-residential systems except where an active thermal runaway propagation prevention system is used. Ask which edition any report was run to.
• Ask about the listing of the system as offered, for example UL 9540 in North America or IEC 62619 for the battery. The IEC describes IEC 62619 as covering secondary lithium batteries “used in industrial applications, including stationary applications”.
• Ask what thermal management, gas and smoke detection, suppression and deflagration protection are included, and what is left to the site.
• Ask for the inputs your AHJ or fire engineer needs, such as layout, separation distances, ventilation and an emergency response plan, and agree who prepares them.

Storing batteries before installation is a separate topic; see our lithium battery warehouse storage fire code guide. For residential systems, see our home battery permit pack guide.

Section 4: documents to request

• datasheets for the system, battery modules and PCS
• test reports and listings for the exact configuration offered (see Section 3)
• the UN38.3 test summary and the SDS; see our LiFePO4 battery SDS guide
• installation, operation and maintenance manuals, and the commissioning procedure
• single-line diagram, layout drawing and the communication interface description

Certificates and test reports are model-specific. Where they don’t exist for the configuration you need, ask whether they can be arranged per project, at whose cost, and how long it would take. Our LiFePO4 safety certifications guide explains what each document proves.

Section 5: logistics, installation and commissioning

• Incoterm, packaging and dangerous-goods shipping responsibility
• who installs, who supplies cabling, busbars and protection, and who connects to the grid
• commissioning scope: on-site or remote, what tests are run, and what records you receive
• training for your operations team, and spare parts to be held on site

EPRI’s data shows why this matters: the construction and commissioning phase is when many failures appear. Agree in writing who checks wiring, cooling and fire protection before the system is energised.

Section 6: commercial terms to ask about

Ask each supplier for their warranty terms (what is covered, for how long, and under what operating conditions), the availability of spares, the lead time and the payment terms. Get them in the quote. This page gives no figures for any of these, and you shouldn’t compare quotes on numbers that were never written down.

The C&I BESS RFQ checklist

Item	What to specify or ask for	Why
Use case and sizing	Use case, kW, usable kWh, cycles per day, site climate and footprint	Quotes are sized against the same duty
PCS and grid	PCS model or the supplier’s proposal; grid code; connection point	Clear integration responsibility
EMS and communications	Controlling system; protocol and interface, confirmed in writing	Avoids controls failures at commissioning
Battery configuration	Chemistry (LFP), module, rack or cabinet configuration, system voltage	Like-for-like comparison
Thermal and fire protection	Cooling, detection, suppression, deflagration protection; UL 9540A data and edition	AHJ approval and site safety
Documents	Datasheets, test reports and listings, UN38.3 summary, SDS, manuals, drawings	Permit, shipping and insurance
Logistics and installation	Incoterm, DG shipping, installation scope, grid connection	No gaps between parties
Commissioning and training	Test plan, records, training, spares	Early-life failures are common
Commercial	Warranty terms, lead time, payment, spares availability. Ask; don’t assume	Comparable, written terms

Where LJY fits

LJY Energy is a Shenzhen supplier and OEM/ODM coordinator for LiFePO4 batteries, not a manufacturer. For C&I projects we take your checklist to qualified manufacturing partners and coordinate the quote, documents and samples. We confirm in writing what each offered configuration includes and which documents exist for it. Relevant options include the C&I battery cabinet (100 kW / 215 kWh class) and the high-voltage rack battery cluster. Installer support is on our installers page.

FAQ

What should a BESS RFQ include?

The use case and sizing, electrical integration, fire safety and code inputs, the documents you need, logistics and commissioning scope, and the commercial terms to be quoted. The checklist table above covers each item.

Is UL 9540A enough for a C&I site?

UL 9540A is test data, not a listing, and what your site needs depends on the code your AHJ has adopted. UL says its 6th edition adds an installation-level large-scale fire test for non-residential systems. Ask which edition a report used, and ask your AHJ what it requires.

Why do C&I batteries fail?

In EPRI’s 2024 analysis of incidents with an assigned root cause, integration, assembly and construction was the most common cause. Only 3 incidents, 11% of those classified, were attributed directly to the cells.

Should I buy the battery and the PCS from one supplier?

Buying both from one supplier gives a single point of responsibility for integration. Buying separately can widen your choice but puts the compatibility risk on you. Ask for both options in the RFQ and compare the scope.

How do I compare quotes?

Send every supplier the same checklist, and ask them to state what is and isn’t included against each line.

Sources

• EPRI: Insights from EPRI’s BESS Failure Incident Database, Analysis of Failure Root Cause (May 2024)
• UL Solutions: installation codes and requirements for ESS, FAQs (UL 9540A 6th edition)
• UL Solutions: UL 9540A test method
• IEC webstore: IEC 62619:2022