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How to Spec a BESS Compression, Thermal or Fire-Barrier Part: What to Send H-O for a Quote
A fast, accurate quote on a die-cut BESS part comes down to nine inputs: the job at each location (compression, thermal isolation, fire barrier, or sealing), the cell format and the preload window from the cell supplier, the expected breathing and end-of-life swelling, the operating and fault temperatures, the system fire-safety approach and its UL 9540A strategy, the environmental class for an outdoor enclosure, the geometry or drawing, the adhesive and facing configuration, and your volumes.
This guide walks each input, explains why it matters, and ends with a spec builder that assembles your answers into a request you can paste straight into the contact form.
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The application problem: an incomplete spec stalls the quote
H-O Products is a precision die-cut converter, and every compression pad, isolation layer, barrier layer and seal is made to order from sheet, slab, blanket or roll stock cut to your drawing. The concrete problem a buyer runs into is the stalled quote: a request that says "I need a battery pad" without the job, the preload window or the fire-safety context cannot be turned into a grade and a price without a follow-up.
The inputs below are the same ones an applications engineer would ask for, so sending them up front turns a back-and-forth into a single response.
The first input does the most work. As covered in the companion guides on BESS material selection and fire-barrier layering, the part is doing one of four jobs: compression (hold cell preload across breathing and swelling), thermal isolation (slow heat between neighbors), fire barrier (support the system's propagation strategy), or sealing (close a hot rack or cabinet joint). The rest of the spec branches from that answer.
Why it is challenging: the key numbers come from other owners
A BESS materials spec is unusual in how many of its governing inputs belong to someone else. The preload window belongs to the cell supplier. The fire-barrier strategy belongs to the system designer working with UL 9540A data under NFPA 855. The transport qualification belongs to the tested battery under UN 38.3.
The converter's job is to turn those owned numbers into a converted part: a pad that stays on its force-deflection plateau across life, a layer at the right thickness, a barrier grade converted to the geometry the design calls for.
A spec that arrives without its owned numbers cannot be matched honestly, which is why the checklist below keeps asking who owns each value.
What to send, input by input
1. The job at each location
List each layer with its function: compression, thermal isolation, fire barrier, or sealing. The jobs map to PORON® microcellular polyurethane, ArmaGel® aerogel insulation, Procell fire-barrier material within the thermal and fire-barrier family, and BISCO® closed-cell silicone respectively. Name each layer's role even when layers are laminated together.
2. Cell format and the preload window
Send the cell format (pouch or prismatic), the stack arrangement, and the preload window from the cell supplier. The compression pad is sized against that window, so this is the single most important number for compression work; if it is still being negotiated, say so and send the working range.
3. Expected breathing and end-of-life swelling
Send the per-cycle breathing and the irreversible swelling estimate across life. These set the deflection range the pad must cover while staying on its working plateau, which in turn sets the thickness and grade direction.
4. Operating and fault temperatures
State the normal operating range and the fault-context temperatures relevant to each layer. Operating temperature gates every family; the fault context informs the isolation and barrier discussion without turning any material into a "fireproof" claim.
5. The fire-safety approach and UL 9540A strategy
Describe the system fire-safety design: where the strategy draws its barrier lines (cell-to-cell, module-to-module, compartment) and what role each layer plays in the UL 9540A evaluation. H-O converts the grade the design specifies; the propagation result is confirmed at the system level, so the strategy is the spec's anchor, not a material adjective.
6. Environmental class for the enclosure
For outdoor cabinets, send the environmental class and exposure so sealing materials and any vent provisions can be matched; for indoor racks, the ambient and the hot-joint temperatures.
7. Geometry, footprint, or a drawing
A dimensioned drawing (DXF, STEP or PDF) is the cleanest input: footprints, cutouts, thicknesses, laminated stack-ups and tolerances in one artifact. A marked-up sketch with dimensions is enough to start a prototype.
8. Adhesive, facing and kitting
Tell us which layers need a pressure-sensitive adhesive, a liner, a facing lamination, or kiss-cut presentation, and whether parts should be kitted per module. Adhesive and facing options vary by family; barrier materials in particular often carry facings per the design.
9. Prototype and annual volume, and a target date
Share the prototype quantity, the expected annual volume, and any target ship date. All parts are custom manufactured to order, and minimum production run quantities apply, so the volume shapes the converting approach and the tooling decision. Prototype quantities through full production are welcome.
The spec at a glance
| Input | Compression | Isolation | Fire barrier | Seal |
|---|---|---|---|---|
| Performance target | Preload window + breathing + swelling | Heat-flow goal at allowable thickness | Role per the UL 9540A strategy | Joint compression at temperature |
| Owner of the key number | Cell supplier | Thermal design | System fire-safety designer | Enclosure design |
| Temperatures | Operating range per layer; fault context for isolation and barrier layers | |||
| Build | Adhesive, liner, facing, laminated stack-ups; kiss-cut and kitting per module | |||
| Geometry | Footprints or dimensioned drawing (DXF / STEP / PDF) | |||
| Commercial | Prototype quantity + annual volume + target date | |||
BESS Compression / Thermal / Barrier RFQ Spec Builder
Job: Cell / module compression pad Cell + preload window: [to be provided] Breathing / swelling: [to be provided] Temperatures: [to be provided] Fire-safety approach: [to be provided] Enclosure environment: [to be provided] Geometry: [to be provided] Build: standard die-cut; thickness [to be provided] Build notes: none stated Commercial: prototype quantity [to be provided]; annual volume [to be provided]; target date [to be provided] Drawing: to follow
Illustrative only; confirm against current material data and a drawing review. This builder formats your inputs into a request; it does not select a grade, size a pad, or assert any fire-safety result. Force-deflection, conductivity, temperature and flame-classification values are confirmed on the manufacturer's current technical data sheet and in an H-O drawing review; fire-propagation behavior is determined at the system level per UL 9540A, and transport qualification per UN 38.3 belongs to the tested battery.
Common failure modes in the spec itself
| Spec gap | Why it stalls the quote | The fix |
|---|---|---|
| "A battery pad," no job named | Compression, isolation, barrier and seal point at four families | Name the layer's job; the family follows |
| Compression request, no preload window | The pad is sized against the cell supplier's window | Send the window, even marked preliminary |
| No swelling estimate | The plateau check needs the end-of-life deflection | Send breathing and end-of-life swelling with the gap |
| "Fireproof material" requested | Not a material property; the system owns propagation | Describe the UL 9540A strategy and the layer's role in it |
| UL 94 V-0 asked to cover the system | A grade-level classification at its thickness, in that test | Use it as a grade gate; keep system claims at the system |
| No volumes | The converting and tooling approach depends on prototype versus production scale | Send both prototype quantity and annual volume |
How H-O Products helps
H-O Products is a precision die-cut converter working across EV and battery programs.
Once your spec is complete, we recommend a family and grade direction across PORON® microcellular polyurethane, ArmaGel® aerogel insulation, Procell fire-barrier material, the wider EV battery thermal and fire-barrier family and BISCO® closed-cell silicone, then convert the stock to your drawing: die-cut, kiss-cut, profiled, laminated with facings, adhesive-backed on liners, and kitted per module.
Documentation available on request includes the material technical data sheet, a certificate of conformance, lot traceability, and first-article inspection, all under our ISO 9001:2015 certified quality management system. We do not produce the raw stock and we do not certify the finished assembly; fire-propagation behavior belongs to the system tested per UL 9540A and transport qualification to the tested battery.
Send the spec, get a quote
Use the builder above to assemble your request, then send it through the contact page with your drawing attached. We will recommend a grade direction and convert samples on your geometry.
Samples typically ship in 3 to 5 business days for common die-cut configurations; standard production runs about two weeks; special orders are quoted to the job.
Family-owned in Winsted, Connecticut since 1971 · ISO 9001:2015 certified · OEMs worldwide send us a drawing — and get back their part.
Related reading
ApplicationBESS Cell Compression, Thermal & Fire-Barrier MaterialsRead →
GuideCompression Pads, Aerogel and Fire Barriers: Choosing BESS Materials by JobRead →
GuideLayering a BESS Fire-Barrier Strategy: Where Compression, Insulation and Barriers Each BelongRead →
IndustryEV & Battery materials overviewRead →
Frequently asked questions
What information should I send to get a useful BESS material recommendation?
Five things move a recommendation from a guess to a real direction: the job at each location (cell or module compression, thermal isolation, fire barrier, or enclosure sealing), the cell format and preload window from the cell supplier for a compression pad, the operating and fault temperatures, the system fire-safety approach and its UL 9540A strategy for a barrier, and the environmental class for an outdoor enclosure.
Add the geometry or a drawing, the adhesive and facing needs, and the volumes, and engineering can match a family and grade direction in one pass.
Why does a compression-pad spec need the cell supplier's preload window?
Because the pad is sized against it. The compression pad's job is to keep cell preload inside the window the cell supplier specifies while the cell breathes each cycle and swells across its life, which means choosing a thickness and grade whose force-deflection plateau covers that growing deflection. Without the window, the most consequential number in the stack is a guess; if the window is preliminary, send it marked preliminary.
Does H-O make the raw compression and barrier materials, and is there a minimum order?
H-O is a precision die-cut converter, not a raw-material producer. We buy sheet, slab, blanket and roll stock from the material manufacturers and convert it to your drawing by die-cutting, kiss-cutting, profiling, lamination, slitting and kitting. Every part is made to order; minimum quantities vary by material and part, and prototype quantities through full production runs are equally welcome. For fire-barrier parts, we convert the grade your fire-safety design specifies and the role is confirmed at the system level.
Request a quote for your battery energy storage (BESS) part
Send H-O your drawing or describe the part—engineering reviews every RFQ and converts samples on your geometry.
Last updated · Reviewed by H-O Products engineering (ISO 9001:2015 certified converter, Winsted, CT).
References
- UL 9540A, Test Method for Evaluating Thermal Runaway Fire Propagation in Battery Energy Storage Systems. UL Standards.
- NFPA 855, Standard for the Installation of Stationary Energy Storage Systems. National Fire Protection Association.
- UN 38.3, Recommendations on the Transport of Dangerous Goods, Manual of Tests and Criteria, lithium battery test series. United Nations.
- ASTM D3574, Standard Test Methods for Flexible Cellular Materials: Slab, Bonded, and Molded Urethane Foams. ASTM International.
This article cites general engineering principles and published standards (UL 9540A for thermal-runaway fire-propagation evaluation, NFPA 855 for installation, UN 38.3 for lithium-battery transport qualification, ASTM D3574 and ASTM D395 for force-deflection and compression set, ASTM D1056 for cellular rubber classification, UL 94 for flammability classification).
Material names refer to material families H-O Products converts. No converted material is fireproof; fire-propagation behavior belongs to the system tested per UL 9540A, flame classifications are grade- and thickness-specific, and transport qualification belongs to the tested battery.
Confirm all values against the manufacturer's current technical data sheet and an engineering drawing review. All parts are custom manufactured to order and minimum production run quantities apply. H-O is a die-cut converter, not a raw-material producer, and does not certify the finished assembly.