A PACK module EOL test system performs the 100% end-of-line inspection of every battery module and PACK: it re-reads voltage and AC internal resistance, verifies BMS communication over RS485 and CAN, checks protection-board behaviour and cell pressure difference, and writes one PASS/FAIL verdict per serial number. NEGUP MACHINE builds them with 8–40 independent channels on the module platform and 1–8 channels on the high-voltage PACK platform, at ±0.05% FS + 0.05% RD accuracy with 94% energy feedback on the PACK class.
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Updated: Oct 10, 2026 · Author: NEGUP Content Team · Reviewer: pending human fact-check before publish.
What "PACK Module EOL" Means on a Line
The phrase covers two jobs. The first is the aging and capacity step: modules are cycled for hours so weak units fail before they are built into a finished PACK. The second is the end-of-line gate: a short, scripted sequence that decides PASS or FAIL and binds that verdict to a serial number. Modern equipment runs both on one platform — the same channel ages overnight and runs the fast EOL script in the morning. Channel count and current range therefore matter more than any headline number.
The Market Behind the Module Gate
Demand for module and pack test capacity tracks cell production with a lag of roughly one process step, so every hour of new gigafactory output creates a matching requirement for formation, grading and end-of-line verification downstream. Two forces push specifications upward. First, safety regulation: China's GB 38031-2025, effective 1 July 2026, raises the insulation basis for traction batteries to at least 100 Ω/V, a trajectory also visible in European and Indian rulemaking. Second, energy cost: a plant running multi-hour aging cycles discharges real kWh, and a resistive-burn design turns that into heat and an air-conditioning bill.
The Channel Architectures We Build
Channel count fixes cost, footprint and throughput, and each channel carries its own power stage, air duct and measurement loop — a 40-channel cabinet is a different machine from an 8-channel one, not a longer version of it.
| Class | Channels | Voltage window | Current range | Feedback |
|---|---|---|---|---|
| Medium-voltage module aging / EOL (BT30V~150V) | 8/16/24/32/36/40 | Charge 0–150 V, discharge 3–150 V | 20 mA–500 A | 90% |
| High-voltage module PACK aging / EOL (BT200V~2000V) | 1–8 | HF 20–1000 V / LF 100–2000 V | 50 mA–1000 A | 94% |
| Power cell aging (BT5V30A~1500A) | 8/16/24/32 | Charge 0–5 V, discharge 1.5–5 V | 20 mA–1500 A | 85% |
| Cell capacity conversion & grading | 8/16/24/32 | Charge 0–5 V, discharge 1.5–5 V | 20 mA–1500 A | 85% |
| Portable PACK analyzer (BP100V20A-2CH) | 2 | Output 5–100 V, 2–24 S | 20 mA–20 A | 92% |
The medium-voltage module class is the volume workhorse: it ages and tests e-bike and e-tricycle packs, power tools, drones, medical equipment, portable energy storage and base-station backup. The high-voltage class exists because a 1000 V PACK cannot be tested on a 150 V channel at all.
The Full SPECS Table
Module EOL systems are won and lost in the last decimal place, not the photograph.
| Parameter | Specification | Why it matters |
|---|---|---|
| Input power | AC 380 V ±10%, 50 Hz | Three-phase supply; 220 V single phase on the analyzer |
| Power factor | ≥99% | No reactive-power penalty |
| Sampling resolution | AD 16 bit | Resolves small voltage steps |
| Input impedance | ≥0.5 Ω | Stable measurement loop at high current |
| AC/DC accuracy | ±0.05% FS + 0.05% RD (25 °C ±10 °C) | Station-to-station consistency beats absolute accuracy |
| Set resolution | 1 mV / 1 mA | Required for fine SOC and DCIR recipes |
| Response / switching | 10 ms (10%–90% FS) / 20 ms | Step changes land inside the recipe; no overshoot |
| Communication | TCP/IP host; RS485 and CAN to BMS | Speaks to both MES and the pack electronics |
| Protection / cooling | IP20, forced air cooling | Independent ducts per channel extend fan life |
| THDi | ≤5% | Harmonic distortion inside plant limits |
| Fixture form | OT terminal / crocodile clip; battery probe on cell class | Determines changeover time |
Two rows are the ones buyers skip and then regret. Switching time decides whether the station can run a cycle-life profile with rapid charge–discharge transitions; fixture form decides how long a changeover takes for a new variant.
The EOL Sequence on a Module Line
On the module platform the script is short and sequenced deliberately: identify first, measure, verify electronics, then decide.
| Stage | What is verified | How |
|---|---|---|
| 1. Identify | Serial and recipe version bound to the batch record | Barcode or RFID scan to host over TCP/IP |
| 2. Voltage & OCV | Total module voltage and cell-string OCV | 16-bit sampling, 1 mV set resolution |
| 3. IR & DCIR | AC internal resistance and DCIR against the recipe | Custom point selection on the DCIR map |
| 4. Charge / discharge | Current follows the command across the window | Independent double closed loop per channel |
| 5. Balance & pressure difference | Cell-to-cell voltage spread in the module | BMS sampling over RS485 and CAN |
| 6. Protection behaviour | Over/under-voltage, over-current, thermal trips | Fault injection and DTC read-back |
| 7. Temperature characteristic | Voltage response across the temperature band | Optional external acquisition channels |
| 8. Verdict & export | PASS/FAIL per serial, raw traces retained | Excel / TXT export, configurable permissions |
Stage six is what separates a real EOL system from a data logger. Tripping a protection threshold on purpose, and confirming the BMS reported it, requires firmware hooks and a fixture that can create the fault safely — precisely what cheaper benches quietly omit.
Cycle Time, Channel Count and the Maths That Sizes the Station
Sizing is arithmetic, not intuition. Take the total test time per module in minutes, divide by the number of channels, and compare against the line takt. A module needing 24 minutes on a 16-channel cabinet delivers one every 1.5 minutes; on an 8-channel cabinet, one every 3 minutes. If your takt is 2 minutes, the 8-channel machine becomes the bottleneck.
The second half of the arithmetic is the energy bill. On discharge the system returns energy to the grid rather than burning it in a resistor bank: 85% cell, 90% medium-voltage module, 94% high-voltage PACK, 92% portable analyzer. A plant discharging 10,000 kWh a month through module aging recovers roughly 9,400 kWh at 94% — the number that pays for the machine.
How the Platform Changes by Cell Format
The script is universal; the electrical window is not. A cylindrical module built from 4680 cells, a prismatic module on EVE LF314 314 Ah cells and a 50 Ah NCM power pouch present different voltages, harnesses and failure modes to the same fixture.
| Attribute | Tesla 4680 | EVE LF314 314 Ah | 50 Ah NCM pouch |
|---|---|---|---|
| Module construction | Low-voltage parallel strings; many weld joints | Series string, 3.2 V nominal per cell | Series string, 3.7 V nominal per cell |
| Dominant EOL failure | Weld resistance drift at the collector | Capacity spread and pressure difference | Swelling and tab weld quality |
| Channel class used | Cell 0–5 V plus module 0–150 V | Module 0–150 V | Module 0–150 V |
| BMS interface | CAN FD, DBC-mapped frames | CAN plus cell-voltage sampling | CAN / RS-485 plus harness check |
| Fixture form | Battery probe / OT terminal | OT terminal / crocodile clip | Crocodile clip, same-mouth |
| Aging reference | 24–72 h | 48–72 h | 24–48 h |
Buy a platform whose recipe covers all three, or you will re-tender when your product mix changes. One cabinet with a stored recipe library handles a cylindrical line today and a prismatic line next quarter without a mechanical rebuild.
Acceptance Criteria to Write Into the RFQ
"We need a module EOL tester" is not a specification. Fix these before you sign.
| Check | Write this into the RFQ |
|---|---|
| Voltage & current window | Exact charge and discharge ranges; whether aging runs on the same channels |
| Channel count | Channels at your line takt, with the arithmetic shown |
| Accuracy class | ±0.05% FS + 0.05% RD at 25 °C ±10 °C; AD 16 bit; 1 mV / 1 mA |
| Dynamic performance | Response 10 ms; switching 20 ms; state whether rapid transitions appear in your profile |
| Energy feedback | Declared efficiency per class; annual kWh recovery at your duty cycle |
| BMS interface | RS485 and CAN supported; DBC or protocol document supplied with the machine |
| Data & integration | Per-serial PASS/FAIL record; export format; TCP/IP host integration documented |
| Acceptance | Trial run on your own modules with documented first-pass yield and repeatability |
The Takeaway: Specify the Gate, Then Prove It
A PACK module EOL test system is where module quality stops being a process claim and becomes a record attached to a serial number. Fix the voltage and current window, then the channel count from your takt, then the accuracy class and feedback efficiency — in that order. Anything sold to you before those numbers are agreed is a datasheet, not a station. NEGUP MACHINE supplies battery testing equipment including the PACK module EOL comprehensive testing system and module PACK aging testing system, plus battery assembly equipment and PACK assembly lines configured to your voltage class and shift volume.
WhatsApp +86 15307690902 | rain@negupgroup.com
Frequently Asked Questions
What is a PACK module EOL test system?
The end-of-line gate on a module or PACK line. In one scripted sequence it re-reads module voltage and internal resistance, verifies BMS communication over RS485 and CAN, checks protection-board behaviour and cell pressure difference, and issues a PASS/FAIL verdict bound to the serial number.
How many channels does a module EOL system need?
Module-class systems run 8, 16, 24, 32, 36 or 40 channels; high-voltage PACK systems run 1 to 8 because each channel carries far more power. Size so that test time divided by channel count stays below your line takt.
What accuracy and dynamic performance should I expect?
±0.05% FS + 0.05% RD at 25 °C ±10 °C with 16-bit AD sampling, 1 mV / 1 mA set resolution, 10 ms response and 20 ms switching. Feedback efficiency is 85% cell, 90% module, 94% high-voltage PACK and 92% portable.
What should the RFQ contain?
The voltage and current window, the channel count at your takt, the accuracy class, the dynamic limits, the feedback efficiency, the BMS interface (RS485 and CAN), the fixture form, the data export, and a trial run on your own modules before final payment — contact NEGUP MACHINE.