A battery terminal RFQ should define three things before suppliers quote: the mating interface, the polarity orientation and the approved connection stack. A familiar appearance or matching nominal thread does not settle all three.
This guide helps buyers turn those requirements into a drawing package and sample-approval plan. For alloy and surface-finish choices, use the separate battery terminal materials guide.
Start with the exact battery interface
Identify the battery manufacturer, model and terminal variant. Attach its current terminal drawing, including the drawing revision. Describe whether the proposed part connects to a tapered post, threaded stud, threaded receptacle or another defined interface.
ODYSSEY's installation manual illustrates distinct SAE positive and negative post dimensions, several threaded interfaces and model-specific terminal arrangements. These examples show why an interface name alone is an incomplete purchasing specification. Use the drawing for the actual mating battery. ODYSSEY installation, operation and maintenance manual.
Ask the supplier to identify every dimension needed to confirm compatibility. For a tapered clamp, request the mating profile and seating reference. For a threaded connection, request the complete thread designation, usable engagement and relevant depth or height limits.
Fix polarity to a defined viewing direction
Create an orientation sketch that labels positive and negative terminals and states the viewing direction. Include a recognizable battery feature as the reference. "Positive on the left" is ambiguous without that reference.
Show cable exits and the surrounding enclosure on the same sketch. Specify how polarity must appear on the part, cover, packaging and drawing. Color can support identification, but the purchasing record should also use explicit polarity labels.
Treat mirrored parts and alternative cable-exit directions as separate configurations requiring confirmation. This gives the supplier a clear basis for identifying substitutions.
Put the mating requirements in the RFQ
The following table is a proposed purchasing checklist. Values and tolerances must come from the approved design and mating-component documentation.
On small screens, swipe or scroll sideways to read every column. Keyboard users can focus the table and use the arrow keys.
| RFQ item | Information to provide | Evidence to request |
|---|---|---|
| Battery interface | Manufacturer, model, terminal variant and drawing revision | Drawing identifying the proposed mating geometry |
| Polarity and orientation | Positive/negative labels, viewing direction and cable exits | Marked orientation sketch for both poles |
| Threaded features | Thread designation, engagement requirement and depth limits | Dimensional report against agreed acceptance limits |
| Cable or lug interface | Cable specification, lug drawing, palm thickness and hole dimensions | Confirmation of the exact mating cable or lug |
| Connection stack | Every lug, adapter, washer and fastener, with their locations | Cross-section or exploded drawing identifying contact surfaces |
| Installation envelope | Available space, cover outline and cable-routing constraints | Sample fit record against the agreed envelope |
Keep material and finish requirements in the same revision-controlled package, even when they have already been discussed separately.
Approve the complete connection stack
A connection stack is the defined arrangement of the terminal, cable lug, any approved adapter and the fastening hardware. Request a drawing that identifies which surfaces make electrical contact and which components provide mechanical retention.
For its Lithium Battery Smart products, Victron shows the cable lug against the battery terminal, with the washers above the lug. This is a documented arrangement for those products; it should not be copied automatically onto another terminal design. Victron Lithium Battery Smart installation manual, section 4.5.
The procurement implication is to approve the arrangement as an assembly. Record lug count, lug thickness, hardware identity, intended contact surfaces and the resulting overall height. Ask the responsible engineer to confirm engagement and clearance across the specified tolerances.
When a proposed change adds another circuit, lug or adapter, reopen that review. If distribution is part of the project, the DC busbar joint and temperature-rise guide provides related RFQ questions.
Review a proposed second lug as an assembly change
Consider a hypothetical RFQ revision: an accessory cable is added above the existing main cable lug, while the supplier proposes keeping the original bolt and cover. No dimensions or test results are assumed in this example. Matching the existing thread is only the first check.
- Confirm permission for the arrangement. Request the battery manufacturer's allowed connection arrangement and the revised stack drawing. If multiple lugs are not supported by the applicable instructions, ask the responsible designer to resolve the distribution method before ordering.
- Check both engagement and clearance. Adding a lug changes the distance occupied by the clamped parts. Have the designer check the resulting engagement, any blind-hole depth limit and the closed cover envelope against the actual tolerances. Simply selecting a longer bolt leaves the depth and cover questions unanswered.
- Identify the contact and load paths. Mark the surfaces intended to conduct current and show how the extra cable is supported. Do not insert an unapproved spacer or washer to make the geometry fit. Victron's documented stack is a product-specific reference, not general permission to rearrange another manufacturer's terminal. Victron connection instructions.
- Record separate dispositions. A drawing may pass a dimensional review while electrical or environmental evidence remains open. The purchase record should identify the accepted revision, unresolved checks and who can release it for the intended application.
Ask the quotation to distinguish the original configuration from the proposed alternative. This prevents the supplier from pricing one stack while the buyer assumes another. Send the revised terminal-stack RFQ with the battery model, both cable-lug drawings and the cover envelope.
Keep torque and electrical limits model-specific
Trojan publishes dry torque requirements by terminal construction and distinguishes connection portions within some terminal assemblies. Its guidance also warns against overtightening. A generic bolt-size torque chart therefore should not replace the applicable battery and terminal instructions. Trojan battery maintenance guidance.
Ask the supplier to identify the applicable assembly instruction, its revision and any stated hardware or surface-condition requirements. Conflicting requirements between mating components need resolution before approval.
This guide does not establish a tightening value, allowable lug count, current rating or universal connection arrangement. Those decisions belong to the responsible system engineer using the exact components and application requirements. Installation and electrical testing must follow the relevant manufacturer instructions and approved work procedures.
Separate dimensional approval from performance approval
Use a dimensional mating fixture or other approved method to assess fit without improvising measurements on an energized installation. Record the sample identity and drawing revision.
The fit review should cover seating, orientation, hardware engagement, cover clearance and cable routing. List the acceptance limits before inspecting the sample, and record discrepancies against those limits.
Keep the electrical and environmental qualification plan separate. Ask which assembly configuration will be evaluated, under what conditions and against which acceptance criteria. A sample that fits addresses a different question from a sample supported by application-relevant performance evidence.
For traceability and changes after sample approval, see the battery cable first-article inspection and change-control guide.
Buyer RFQ checklist
Before requesting a quotation, assemble:
- The battery model, terminal drawing and revision.
- A polarity and cable-exit orientation sketch.
- Cable, lug, cover and hardware part references.
- The proposed connection-stack drawing and installation envelope.
- Application conditions and the electrical duty requiring engineering review.
- Dimensional acceptance criteria and the requested qualification evidence.
- Sample quantity, order quantity, packaging and destination market.
- A requirement to disclose proposed substitutions before approval.
Browse the battery terminal category to identify reference designs, then send the specification package. Ask the quotation to distinguish confirmed requirements from unresolved engineering questions.
Buyer FAQ
Can the same clamp be specified for positive and negative posts?
Only when the proposed design is documented and approved for both mating interfaces. ODYSSEY's SAE drawings distinguish positive and negative geometry, so do not infer interchangeability from a photograph or a broad "battery clamp" description. ODYSSEY terminal reference drawings.
Is an M8 description enough to confirm compatibility?
No. Request the full threaded-interface details, mating lug dimensions, hardware arrangement and available space. The battery model also matters: Victron's cited manual assigns different torque requirements to different models that both use M8 connections. Victron installation specifications.
Does a material certificate prove the assembled connection is suitable?
A material certificate addresses the material information within its scope. Ask separately for dimensional conformity and any required assembly-level qualification evidence. Each document should identify the relevant part or configuration, revision, test scope and acceptance criteria.
What is needed to confirm price, MOQ and lead time?
Provide the approved configuration, quantities, sample requirements, packaging and requested evidence. Ask the supplier to state quotation assumptions and identify anything still awaiting confirmation. Obtain price, minimum order quantity and delivery timing for that specific inquiry.
Can another lug be added if the original bolt still tightens?
Tightening alone does not establish an approved connection. Confirm the manufacturer's permitted arrangement, actual thread engagement and depth, contact surfaces, cable support and cover clearance. Record the additional lug as a configuration change requiring the applicable design and performance review.