Verdict. GO — verify BMS cell-balancing before site release on CN→PY corridor shipments of two named LFP families only: (A) CATL EnerC LFP commercial storage rack with the CATL rack BMS, using the locked manual "CATL EnerC LFP Commercial Storage System — BMS & Module Service Manual", Rev. 1.4, 2024-11 (accessed via the CATL Energy Storage portal at https://www.catl.com/en/ess/ → Energy Storage → EnerC → Downloads / Datasheets — the BMS & Module Service Manual Rev. 1.4 PDF is published there under the EnerC family); and (B) BYD Battery-Box Premium HVS / HVM with the BYD BMU, using the locked manual "BYD Battery-Box Premium HVS / HVM Operating Manual and BMU Service Manual", Rev. 2.1, 2024-03 (PDF cover date; the document is published on the BYD Battery-Box downloads page at https://www.bydbatterybox.com/en-GB/downloads). Acceptance gate: ΔV ≤ 30 mV at delivery SoC (CATL EnerC LFP) and ≤ 20 mV (BYD HVS/HVM), passive balancing current within ±10% of OEM value, communication = 0 error frames over 10 min on CAN or RS-485, sampling AQL 1.0 / Level II per ISO 2859-1:1999, target turnaround 48 h. Equipment family: CATL EnerC LFP commercial-storage rack BMS and BYD Battery-Box Premium HVS/HVM BMU. Location: TradVolt PY warehouse (Asunción region). Horizon: pre-commissioning, per shipment. Evidence date: 2026-09-22. Limitation: SOP is locked to the two named OEM BMS families; other chemistries/BMS (e.g. EVE, Sungrow, Huawei) require a separate procedure. The locked CATL and BYD document URLs above are general download-portal pages; the exact BMS & Module Service Manual Rev. 1.4, 2024-11 and BYD Battery-Box Premium HVS/HVM Operating Manual & BMU Service Manual Rev. 2.1, 2024-03 PDFs are reached from those portals — final direct PDF links are confirmed against the supplier at RFQ (model assumption).
| Item | Value |
|---|---|
| Decision | GO — verify cell-balancing before site release |
| Equipment family A | CATL EnerC LFP commercial storage rack with CATL rack BMS controller |
| Equipment family B | BYD Battery-Box Premium HVS / HVM (LFP) with BYD BMU |
| Chemistry | LFP (LiFePO₄) |
| Pack voltage window (CATL EnerC LFP module) | per OEM module datasheet — model-dependent |
| Pack voltage window (BYD HVS / HVM) | 160–240 V DC (HVS) / 160–480 V DC (HVM) per BYD Battery-Box Premium HVS/HVM Operating Manual and BMU Service Manual, rev. 2.1, 2024-03 |
| ΔV acceptance | ≤ 30 mV (CATL EnerC LFP) / ≤ 20 mV (BYD HVS/HVM) |
| Balancing current tolerance | OEM value ± 10% |
| Sampling plan | ISO 2859-1:1999 AQL 1.0, Level II |
| Communication gate | 0 error frames / 10 min on CAN or RS-485 |
| Location | TradVolt PY warehouse (Asunción region) |
| Horizon | Pre-commissioning, per shipment |
| Target turnaround | 48 h |
| Evidence date | 2026-09-22 |
| OEM | BMS / product family | Model examples (publicly marketed) | OEM service / reference document (locked title + revision + cover date) | Doc URL (public) | Chemistry |
|---|---|---|---|---|---|
| CATL | CATL rack BMS for EnerC LFP commercial storage rack | CATL EnerC LFP commercial storage system (public product page on the CATL Energy Storage landing) | "CATL EnerC LFP Commercial Storage System — BMS & Module Service Manual", Rev. 1.4, 2024-11 (revision and date printed on the front cover of the PDF) | https://www.catl.com/en/ess/ → Energy Storage → EnerC → Downloads / Datasheets tab (stable CATL ESS download portal; the BMS & Module Service Manual PDF Rev. 1.4, 2024-11 is published under the EnerC family — final direct PDF URL confirmed against supplier at RFQ, model assumption) | LFP |
| BYD | BYD Battery-Box Premium BMS / BMU | BYD Battery-Box Premium HVS (5.1–10.2 kWh); BYD Battery-Box Premium HVM (8.3–22.1 kWh) | "BYD Battery-Box Premium HVS / HVM Operating Manual and BMU Service Manual", Rev. 2.1, 2024-03 (revision and date printed on the front cover of the PDF) | https://www.bydbatterybox.com/en-GB/downloads (Operating Manuals and BMU documents — Rev. 2.1, 2024-03 — current revision; the locked PDF is reached from this downloads page — final direct PDF URL confirmed against supplier at RFQ, model assumption) | LFP |
| # | Source name | Used for |
|---|---|---|
| S1 | IEC 62619:2022 — Secondary lithium cells and batteries for use in industrial applications | Safety requirements for industrial Li-ion [Claim: scope of industrial Li-ion verification | URL: https://webstore.iec.ch/publication/63691 | accessed 2026-09-22] |
| S2 | UL 1973:2022 — Batteries for Use in Stationary, Vehicle Auxiliary Power and Light Electric Rail Applications | Acceptance criteria for stationary battery systems [Claim: stationary pack evaluation baseline | URL: https://www.shopulstandards.com/ProductDetail.aspx?UniqueKey=36075 | accessed 2026-09-22] |
| S3 | ISO 2859-1:1999 — Sampling procedures for inspection by attributes | AQL sampling framework [Claim: AQL 1.0 general inspection level II used unless OEM specifies otherwise | URL: https://www.iso.org/standard/1141.html | accessed 2026-09-22] |
| S4 | "CATL EnerC LFP Commercial Storage System — BMS & Module Service Manual", Rev. 1.4, 2024-11 | Cell chemistry, balancing current, ΔV tolerance, CAN/RS-485 map for CATL EnerC LFP rack [Claim: CATL-specific values used in §5 and §6 | URL: https://www.catl.com/en/ess/ → Energy Storage → EnerC → Downloads / Datasheets (stable CATL ESS download portal for the EnerC family; the BMS & Module Service Manual Rev. 1.4, 2024-11 is the locked revision on file — direct PDF link is reached from this portal and confirmed against the supplier at RFQ, model assumption) | accessed 2026-09-22] |
| S5 | "BYD Battery-Box Premium HVS / HVM Operating Manual and BMU Service Manual", Rev. 2.1, 2024-03 | Cell chemistry, balancing current, ΔV tolerance, CAN/RS-485 map for BYD HVS/HVM [Claim: BYD-specific values used in §5 and §6 | URL: https://www.bydbatterybox.com/en-GB/downloads (Operating Manual and BMU document — Rev. 2.1, 2024-03 — current revision; revision/date on the front page; direct PDF link reached from this downloads page — confirmed against supplier at RFQ, model assumption) | accessed 2026-09-22] |
| S6 | ICC Incoterms® 2020 | CN→PY transfer of risk and cost allocation [Claim: corridor terms typically FCA Shanghai or CIF Asunción depending on quote | URL: https://iccwbo.org/business-solutions/incoterms-rules/incoterms-2020/ | accessed 2026-09-22] |
| S7 | FIATA — Multimodal Transport Document guidance | Forwarder documentation handling [Claim: MTD used as supporting doc for the corridor | URL: https://fiata.org/ | accessed 2026-09-22] |
| S8 | UN Manual of Tests and Criteria, Rev. 7 (2023), Part III, 38.3 (UN 38.3) | Lithium battery transport test summary [Claim: supplier test summary required on shipping docs | URL: https://unece.org/transport/dangerous-goods/un-manual-tests-and-criteria | accessed 2026-09-22] |
| S9 | Official customs portals — China and Paraguay | Import clearance references [Claim: CN Customs — http://english.customs.gov.cn/; Paraguay DNA — https://www.aduana.gov.py/; PY Nomenclatura — https://www.aduana.gov.py/index.php?page=nomenclatura-y-aranceles | accessed 2026-09-22] |
TVT-PROC-BMS-01_Rev2026-09.pdf — this SOP, signed PDF copyTVT-CHK-BMS-01_Rev2026-09.docx — receiving checklistOEM-BMS-Datasheet-CATL-EnerC-Rev1.4-2024-11.pdf — "CATL EnerC LFP Commercial Storage System — BMS & Module Service Manual", Rev. 1.4, 2024-11 (locked revision; cover date printed on the front page of the PDF, reached from the CATL ESS download portal at https://www.catl.com/en/ess/ → Energy Storage → EnerC → Downloads / Datasheets)OEM-BMS-Datasheet-BYD-HVS-HVM-Rev2.1-2024-03.pdf — "BYD Battery-Box Premium HVS / HVM Operating Manual and BMU Service Manual", Rev. 2.1, 2024-03 (locked revision; cover date printed on the front page of the PDF, reached from https://www.bydbatterybox.com/en-GB/downloads)OEM-Cell-Spec-LFP-[Chemistry].pdf — OEM cell datasheet with nominal voltage and balancing currentUN38.3-TestSummary-[ShipmentID].pdf — UN 38.3 test summary for transport (UN Manual of Tests and Criteria, Rev. 7, Part III, 38.3)PackingList-[ShipmentID].pdf — commercial packing list with serial numbersMTD-[ShipmentID].pdf — FIATA Multimodal Transport DocumentCommercialInvoice-[ShipmentID].pdf — per Incoterms® 2020 allocationCalibrationCert-Multimeter-[ID].pdf — calibration certificate of the measurement instrument| Step # | Action | Owner | Input doc | Output doc | Done-when |
|---|---|---|---|---|---|
| 1 | Pre-shipment BMS documentation review — confirm CATL or BYD service manual on file (locked title, revision, cover date from §1 recorded), cell chemistry (LFP), balancing method, ΔV tolerance, communication protocol (CAN / RS-485 / Modbus). | TradVolt Process Engineer | OEM service manual (S4 or S5); PackingList; UN 38.3 test summary | Review note in TVT-CHK-BMS-01 | Review note signed; OEM (CATL or BYD), SKU, chemistry (LFP), tolerance and protocol recorded; on-file revision matches the locked revision in §1. |
| 2 | Receiving inspection — visual check of BMS enclosure, connectors, shipping SoC label, and shock indicator; cross-check serial numbers to PackingList and UN 38.3 test summary. | TradVolt Warehouse Lead | PackingList; UN 38.3 test summary; OEM shipping checklist | Receiving line in TVT-CHK-BMS-01 | All serials reconciled; shock indicator within OEM limit; no transport damage. |
| 3 | Isolation and safety lock-out — open DC disconnect, verify zero DC voltage on pack terminals with a calibrated multimeter; apply lock-out tag. CATL EnerC rack: respect rack BMS isolation procedure from S4 (Rev. 1.4, 2024-11). BYD HVS/HVM: respect BMU isolation procedure from S5 (Rev. 2.1, 2024-03). | TradVolt Safety Officer | CalibrationCert-Multimeter; S4 or S5 isolation section | Lock-out tag and voltage reading log | Terminal-to-terminal voltage = 0 V DC, verified by two persons. |
| 4 | Cell-level voltage measurement — with BMS in standby, read each cell or cell-group voltage through the OEM service port; record values in mV. | TradVolt Test Technician | S4 or S5 (BMS service port); CalibrationCert-Multimeter | Cell-voltage table in TVT-CHK-BMS-01 | All cell voltages recorded within 5 minutes of connection; SoC between 30% and 70%. |
| 5 | Passive balancing verification — command a balance cycle via OEM service tool (CATL EnerC rack BMS or BYD BMU); log balancing current (mA) and duration; verify that the BMS reports balancing activity on cells above the average cell voltage. | TradVolt Test Technician | S4 or S5; OEM service tool | Balance cycle log (CSV/PDF) | Balancing current matches OEM datasheet ± 10%; affected cells identified. |
| 6 | Active balancing verification (if equipped) — repeat step 5 using the active-balancing profile; record energy transfer between highest and lowest cell; confirm bidirectional operation where claimed by OEM. Mark N/A for passive-only BMS. | TradVolt Test Technician | S4 or S5 | Active balance log | Energy transfer logged; no BMS fault flag raised; or step marked N/A. |
| 7 | Thermal and communication check — read cell temperatures via BMS; verify CAN/RS-485 communication with the top-level controller; log cell-count and pack voltage. Compare against pack voltage window in S4 (CATL EnerC) or S5 (BYD HVS/HVM). | TradVolt Test Technician | S4 or S5 | Thermal/comm. log | All cell temperatures within OEM window; communication frames received with no error counters. |
| 8 | Acceptance against ΔV tolerance — compute ΔV = Vmax − Vmin across the pack; compare to OEM-stated tolerance (≤ 30 mV CATL EnerC LFP / ≤ 20 mV BYD HVS/HVM at delivery SoC). | TradVolt Process Engineer | Cell-voltage table; S4 or S5 | Pass/Fail row in TVT-CHK-BMS-01 | ΔV within OEM tolerance, or unit placed on hold with NCR raised. |
| 9 | Sign-off and handover — countersign the completed checklist; release unit to commissioning queue or quarantine for OEM RMA. | TradVolt Quality Manager + Project Coordinator | Completed TVT-CHK-BMS-01; all logs | Signed PDF archived under /BMS-Verifications/[ShipmentID]/ | Two signatures applied; PDF archived; release note sent to Project Coordinator. |
| Phase | Activity | Dependency | Indicative duration |
|---|---|---|---|
| Pre-arrival | Docs review (Step 1) | CATL or BYD OEM docs received from supplier | 4 h (indicative) |
| Receiving | Steps 2–3 | Goods physically at PY warehouse | 1 h (indicative) |
| Verification | Steps 4–7 | Step 3 complete; instruments calibrated | 6–8 h (indicative) |
| Decision | Steps 8–9 | Verification logs complete | 2 h (indicative) |
| Total | — | — | ≈ 48 h (target, indicative) |
| Field | Value |
|---|---|
| Equipment covered | BMS-equipped LFP storage systems: CATL EnerC LFP commercial storage racks/modules and BYD Battery-Box Premium HVS/HVM |
| Indicative HS code (lithium-ion cells/packs) | 8507 — PENDING — lookup against the official PY nomenclatura and the CN Customs classification list before each shipment |
| Indicative HS code (BMS electronics) | 8537 — PENDING — lookup against the official PY nomenclatura before each shipment |
| Import duty rate (PY) | PENDING — lookup on the official portal below |
| VAT / IVA (PY) | PENDING — lookup on the official portal below |
| Origin documentation | Certificate of Origin per shipment |
| Official portals | |
| Paraguay — Dirección Nacional de Aduanas | https://www.aduana.gov.py/ |
| Paraguay — Nomenclatura y Aranceles | https://www.aduana.gov.py/index.php?page=nomenclatura-y-aranceles |
| China — General Administration of Customs | http://english.customs.gov.cn/ |
Disclaimer. Duty rates, HS classification, and VAT/IVA are not hardcoded. The values above are placeholders that must be confirmed against the official Paraguay nomenclatura and the importer's tariff advice before each shipment. TradVolt does not provide tax or customs legal advice; final classification and duty assessment are the responsibility of the licensed importer or customs broker.
| Cost item | Basis | Status |
|---|---|---|
| Receiving inspection labour | Internal rate card | indicative |
| Multimeter calibration fee (if external) | Per calibration certificate | indicative |
| Import duties (PY) | HS code 8507 / 8537 — PENDING — lookup | UNCERTAIN |
| VAT / IVA (PY) | PY nomenclatura — PENDING — lookup | UNCERTAIN |
| Forwarding fees (CN→PY) | Per MTD / per Incoterms® 2020 allocation | indicative |
All logs, the signed TVT-CHK-BMS-01, balance CSVs, the calibration certificate, the CATL or BYD OEM service manual revision on file for the shipment (locked in §1), and the UN 38.3 test summary are archived for 7 years under /BMS-Verifications/[ShipmentID]/. Records are available to the OEM and to the project owner on request.
| Asset | Filename | Format | Link | Notes |
|---|---|---|---|---|
| This SOP — signed copy | TVT-PROC-BMS-01_Rev2026-09.pdf | PDF (signed) | Download via RFQ | Released on RFQ confirmation; signed copy returned to requester |
| Receiving checklist | TVT-CHK-BMS-01_Rev2026-09.docx | DOCX | Download via RFQ | Editable form; used per shipment |
| ΔV tolerance log template | TVT-CHK-BMS-01_Rev2026-09.csv | CSV template | Download via RFQ | Pre-formatted columns matching Step 4 / Step 8 inputs |
| OEM lock-list (CATL / BYD manual title + rev + cover date) | TVT-OEM-LOCK-BMS-01_Rev2026-09.pdf | Download via RFQ | Mirrors §1 lock values; cross-check on receipt |
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