All tests at a glance — GB 38031-2025
A single-page reference for the 24 safety tests defined in GB 38031-2025. Use it to scan parameters; use the per-test pages for full procedure, setup, and edge cases.
How to read this page
- Clause — the section in GB 38031-2025 where the test method is defined (8.x). Pass criteria live one section earlier (5.x).
- Object — the level the test applies to:
cell, pack, system, or pack/system/vehicle.
- Key parameters — the must-knows. Full conditions on the per-test page.
- Pass —
STD is the universal pack/system criterion (see below). Anything else is spelled out.
- Observation — quiet observation period at test environment temperature after the test ends.
- Status — change vs. GB 38031-2020, derived from the preface change list:
new — clause did not exist in 2020revised — clause existed in 2020 but requirements and/or test method changedunchanged — clause not listed in the 2020→2025 change list (assume unchanged; verify against 2020 text before relying)
Universal conventions
Unless a row says otherwise:
| Shorthand |
Meaning |
| STD (pass) |
After test: no leakage, no housing crack, no fire, no explosion. Insulation resistance ≥ 100 Ω/V (DC); ≥ 500 Ω/V if AC circuit present. Per clauses 5.2.x. |
| Test environment |
22 °C ± 5 °C, RH 10–90 %, 86–106 kPa. Clause 6.1.1. |
| SOC |
Highest working SOC specified by manufacturer. Clause 6.1.10. |
| Insulation method |
Per Appendix B (Method 1: voltage-divider; Method 2: insulation-resistance meter @ ≥1.5× nominal V or 500 V DC). |
Cell-level tests (Section 8.1, 7 tests)
| # |
Clause |
Test (EN) |
Object |
Key parameters |
Pass |
Observation |
Status |
| 1 |
8.1.2 |
Over-discharge |
cell |
Adjust SOC to discharge-termination voltage; discharge at I₁ for 30 min |
No fire, no explosion |
1 h |
revised (method) |
| 2 |
8.1.3 |
Overcharge |
cell |
Standard charge → continue at ≥ I₃ to 1.1× charging-termination voltage or 115 % SOC |
No fire, no explosion |
1 h |
unchanged ⚠ |
| 3 |
8.1.4 |
External short circuit |
cell |
Short positive↔negative terminals for 10 min; external R < 5 mΩ |
No fire, no explosion |
1 h |
unchanged ⚠ |
| 4 |
8.1.5 |
Heating |
cell |
Chamber from ambient at 5 °C/min to 130 °C; hold 30 min (NiMH: 85 °C, hold 2 h) |
No fire, no explosion |
1 h |
revised (method) |
| 5 |
8.1.6 |
Temperature cycling |
cell |
5 cycles per Table 1: 25 → −40 °C (60 min) → hold 90 min → 25 °C → 85 °C (90 min) → hold 110 min → 25 °C; ramp rates 13/12, 2/3, 6/7 °C/min |
No fire, no explosion |
1 h |
unchanged ⚠ |
| 6 |
8.1.7 |
Compression (extrusion) |
cell |
Semi-cylindrical plate r = 75 mm, length > cell width; speed ≤ 2 mm/s; stop at V = 0, or 15 % deformation, or 100 kN, or 1 000 × cell mass; hold 10 min |
No fire, no explosion |
1 h |
revised (method) |
| 7 |
8.1.8 |
Safety after fast-charge cycles 🆕 |
cell |
Cell capable of 20→80 % SOC in ≤ 15 min. Cycle 20↔80 % SOC 300 times (each leg ≤15 min, 30 min rest), then run 8.1.4 external short |
No fire, no explosion (after the 8.1.4 step) |
1 h (per 8.1.4) |
new |
Pack & system — Mechanical (Section 8.2, 5 tests)
| # |
Clause |
Test (EN) |
Object |
Key parameters |
Pass |
Observation |
Status |
| 8 |
8.2.1 |
Vibration |
pack/system |
Random + sine on x/y/z per Table 2 (non-M1/N1: RMS x 0.52 g, y 0.57 g, z 0.73 g; sine 20 Hz ±1.5/1.5/2.0 g, 2 h/axis) or Table 3 (M1/N1: RMS x 0.50 g, y 0.45 g, z 0.64 g; sine 24 Hz ±1.0/1.0/1.5 g, 1 h/axis). Roof-mounted: per manufacturer, no less than Table 2/Fig 2 ⚠ |
STD |
2 h |
revised |
| 9 |
8.2.2 |
Mechanical shock |
pack/system |
Half-sine, ±z axis, 7 g, pulse 6 ms, 6 shocks per direction (12 total); inter-shock interval ≥ 5× pulse |
STD |
2 h |
revised (req) |
| 10 |
8.2.3 |
Simulated collision |
pack/system |
Pulse on x and y per Table 6, scaled by vehicle curb weight class (≤3.5 t / >3.5–<7.5 t / ≥7.5 t). Peak x-acc 28/17/12 g; peak y-acc 15/10/10 g (full envelope in Table 6) ⚠ |
STD |
2 h |
revised (req) |
| 11 |
8.2.4 |
Compression |
pack/system |
Plate: 75 mm semi-cyl (L ≤ 1 m) or 600×600 mm with three 75 mm semi-cyls @ 30 mm pitch. Direction: x and y. Speed ≤ 2 mm/s. Stop at 100 kN or 30 % deformation in compression direction (with body structure: stop at 100 kN). Hold 10 min |
No fire, no explosion + insulation (no leakage/crack requirement) |
2 h |
revised |
| 12 |
8.2.16 |
Bottom impact 🆕 |
pack/system/vehicle |
Impactor: hemispherical, Ø 30 mm, 10 kg, 45# steel. Direction: +z. Three manufacturer-defined risk points (front/middle/rear). Energy 150 J ± 3 J. Exemption: N-class vehicles with min ground clearance ≥ 200 mm fully loaded |
STD |
2 h |
new |
Pack & system — Environmental (Section 8.2, 5 tests)
| # |
Clause |
Test (EN) |
Object |
Key parameters |
Pass |
Observation |
Status |
| 13 |
8.2.5 |
Damp heat cycling |
pack/system |
GB/T 2423.4 Test Db; max temp 60 °C (or higher per mfr); 5 cycles |
STD; insulation measured within 30 min after test |
2 h |
revised (req) |
| 14 |
8.2.6 |
Immersion |
pack/system |
Choose: Method 1 — 3.5 % NaCl by mass, fully submerged in vehicle orientation, 2 h; or Method 2 — IPX7 per GB/T 4208-2017 §14.2.7, 30 min, fresh water (pack < 850 mm: lowest point ≥ 1 000 mm below water; ≥ 850 mm: highest point ≥ 150 mm below); ΔT(water↔object) ≤ 5 °C. Test object must have already passed 8.2.1 vibration |
Method 1: no fire, no explosion. Method 2: STD + IPX7 met |
2 h |
revised (req) |
| 15 |
8.2.8 |
Temperature shock |
pack/system |
Alternate −40 °C ↔ 60 °C (or stricter per mfr); transition ≤ 30 min; hold 8 h at each extreme; 5 cycles |
STD |
2 h |
revised |
| 16 |
8.2.9 |
Salt fog |
pack/system |
Per GB/T 28046.4-2011 §5.5.2 + GB/T 2423.17-2024. NaCl solution (50 ± 5) g/L, pH 6.5–7.2 @ 35 °C. Cycle: spray 8 h @ 35 °C, then dwell 16 h (24 h cycle). Low-voltage power-on monitoring during hours 4–5. 6 cycles total. Exempt if pack is fully inside passenger/luggage/closed cargo compartment |
STD |
(not specified separately) ⚠ |
revised |
| 17 |
8.2.10 |
High altitude |
pack/system |
61.2 kPa (≈ 4 000 m), ambient T. Stand 5 h, then discharge at ≥ I₃ to discharge-termination |
STD |
2 h |
revised |
Pack & system — Electrical protection (Section 8.2, 5 tests)
All tests in this group: ambient 20 °C ± 10 °C unless noted; non-cooling protection devices active.
| # |
Clause |
Test (EN) |
Object |
Key parameters |
Pass |
Observation |
Status |
| 18 |
8.2.11 |
Over-temperature protection |
system |
Continuous charge/discharge to drive cell T up; chamber ramps from 20 ± 10 °C to mfr's overheat-protection threshold (or, if none, max operating T). Stop on: auto cutoff, mfr signal, or T stable (ΔT < 4 °C over 2 h) |
STD |
1 h |
revised |
| 19 |
8.2.12 |
Over-current protection |
system |
External DC supply; mid-SOC. Charge at max-normal current, then ramp to over-current level within 5 s. Stop on: auto cutoff, mfr signal, or T stable (ΔT < 4 °C over 2 h) |
STD |
1 h |
revised |
| 20 |
8.2.13 |
External short-circuit protection |
system |
Short positive↔negative; external R ≤ 5 mΩ. Maintain until: protection trips, or housing T stable (ΔT < 4 °C over 2 h), then short for ≥ 1 h more |
STD |
1 h |
revised (req) |
| 21 |
8.2.14 |
Overcharge protection |
system |
External charging, control limits disabled, shortest-allowed charging strategy. Stop on: auto cutoff, mfr signal, T exceeds max operating T by 10 °C, or (if no cutoff and T stays 10 °C below max) continue 12 h |
STD |
1 h |
revised |
| 22 |
8.2.15 |
Over-discharge protection |
system |
Lower-SOC start; discharge at stable current within normal range. Stop on: auto cutoff, mfr signal, voltage reaches 25 % of rated, or T stable (ΔT < 4 °C over 2 h) |
STD |
1 h |
revised (req) |
Pack & system — Thermal stability (Section 8.2, 2 tests)
| # |
Clause |
Test (EN) |
Object |
Key parameters |
Pass |
Observation |
Status |
| 23 |
8.2.7.1 |
External fire |
pack/system |
Ambient T > 0 °C, wind ≤ 2.5 km/h. Gasoline pan: footprint = pack horizontal projection +20 cm to +50 cm; pan height ≤ 8 cm above gasoline; water bottom layer. Pack-bottom-to-gasoline gap = 50 cm or vehicle ground clearance. Stages: preheat 60 s → direct burn 70 s → indirect burn 60 s with fire-resistant brick screen (SK 30, 30–33 % Al₂O₃, density 1 900–2 000 kg/m³, hole area 44.18 %) → remove |
No explosion (fire allowed) |
2 h or until ext. T < 45 °C |
revised |
| 24 |
8.2.7.2 / App. C |
Thermal propagation ⭐ |
pack/system/vehicle |
Trigger TR in a centrally located cell via one of: needle (steel, Ø 3–8 mm, conical tip 20–60°, speed 0.1–10 mm/s, depth ≤ 90 % cell dimension), external heating (power per Table C.2: 30–300 W for E < 100 Wh up to >600 W for E ≥ 800 Wh), or internal heating plate (Cu + insulation, 15×15 to 60×60 mm, ≤ 0.5 mm thick, 150–700 W or 200–700 W per Table C.3). TR confirmed by (a OR b) AND c: a) voltage drop > 25 %, b) T at monitor reaches mfr max op T, c) dT/dt ≥ 1 °C/s for > 3 s. SOC: ≥ 95 % (externally chargeable) or ≥ 90 % (vehicle-charged only) |
No fire, no explosion + thermal-event warning ≤ 5 min after TR triggered + smoke does not endanger passenger compartment within 5 min before/after warning (vehicle-level: smoke must not enter cabin in that window) |
Until all monitoring points ≤ 60 °C, min 2 h |
revised (req + Appendix C) |
Quick filters
New in 2025
| # |
Clause |
Test |
| 7 |
8.1.8 |
Safety after fast-charge cycles (cell) |
| 12 |
8.2.16 |
Bottom impact (pack/system/vehicle) |
Tests with vehicle-category-dependent parameters
| # |
Clause |
Test |
Variants |
| 8 |
8.2.1 |
Vibration |
M1/N1 vs other; roof-mounted special case |
| 10 |
8.2.3 |
Simulated collision |
≤3.5 t / >3.5–<7.5 t / ≥7.5 t curb weight |
| 12 |
8.2.16 |
Bottom impact |
N-class with ≥ 200 mm ground clearance: exempt |
The thermal-runaway warning rule (5 min)
Lives in 8.2.7.2 / Appendix C and is the headline change. The warning signal must be issued no later than 5 minutes after thermal runaway is triggered in the trigger cell. Smoke must not endanger the passenger compartment in the 10-minute window centered on the warning (5 min before, 5 min after). For vehicle-level tests this hardens to: smoke must not enter the cabin.
Implementation timeline (clause 10)
| Population |
Effective date |
| Document released |
2025-03-28 |
| Standard takes effect |
2026-07-01 |
| New vehicle type approvals must comply |
from 2026-07-01 |
| Already-approved vehicle models must comply |
from 2027-08-01 (13 months after) |
Source and verification notes
All values transcribed from the English-translation PDF of GB 38031-2025 (the version supplied as China BATTERY STANDARD.pdf, 39 pages, released 2025-03-28). Citations are by clause number; the PDF can be opened to that clause for verification.
Rows flagged ⚠ for verification
| Row |
Field |
Why flagged |
Action |
| 2 (8.1.3 overcharge cell) |
Status: unchanged |
Preface change list does not mention 8.1.3, so I marked unchanged. Worth confirming against the 2020 text — preface lists are sometimes incomplete. |
Cross-check 2020 PDF clause 8.1.3 |
| 3 (8.1.4 ext short cell) |
Status: unchanged |
Same reason. |
Cross-check 2020 PDF clause 8.1.4 |
| 5 (8.1.6 temp cycling cell) |
Status: unchanged |
Same reason. |
Cross-check 2020 PDF clause 8.1.6 + Table 1 |
| 8 (8.2.1 vibration) |
Roof-mounted parameters |
PDF says "no less than Table 2/Fig 2 parameters" but Figure 2 isn't in the text extraction (graphic only). |
Confirm figure values in PDF page 18 |
| 10 (8.2.3 simulated collision) |
Full pulse envelope |
Table 6 has 8 control points × 3 weight classes × 2 axes. I summarized peak x/y values; the per-test page should show the full table. |
Verify Table 6 page 20 |
| 16 (8.2.9 salt fog) |
Observation period |
Standard does not state a separate post-test observation for salt fog — testing is the cycle. Listed as "not specified separately." |
Confirm clause 8.2.9; likely no separate observation |
Universal pass-criterion exception in clause 5.2.4
The compression test (8.2.4) is the only pack/system test where leakage and housing cracks are explicitly allowed — clause 5.2.4 requires only "no fire or explosion" plus the insulation threshold. Worth highlighting on the per-test page and in pass/fail criteria.
Status assignments — methodology
The status column reflects whether the clause appears in the GB 38031-2020 → 2025 change list in the preface (PDF pages 5–6). The preface distinguishes "requirements revised" from "test method revised":
- Requirements revised only (5.x clauses listed without 8.x): mechanical shock (5.2.2), simulated collision (5.2.3), damp heat (5.2.5), immersion (5.2.6), external short protection (5.2.13), over-discharge protection (5.2.15)
- Both revised (both 5.x and 8.x listed): vibration, compression (pack), thermal stability, temperature shock, salt fog, high altitude, over-temp, over-current, overcharge protection, bottom impact (new)
- Method-only revised (cell tests where preface lists only 8.x): over-discharge (8.1.2), heating (8.1.5), compression (8.1.7)
For the "Migrating from 2020" pages, this distinction matters — write delta_vs_2020: requirements vs delta_vs_2020: method vs delta_vs_2020: both in frontmatter.
Build manifest
This page is the build manifest. Each numbered row corresponds to one test page that needs to exist:
docs/tests/
├── cell-level/
│ ├── over-discharge.md # row 1
│ ├── overcharge.md # row 2
│ ├── external-short-circuit.md # row 3
│ ├── heating.md # row 4
│ ├── temperature-cycling.md # row 5
│ ├── compression.md # row 6
│ └── safety-after-fast-charge.md # row 7 🆕
├── pack-system/
│ ├── mechanical/
│ │ ├── vibration.md # row 8
│ │ ├── mechanical-shock.md # row 9
│ │ ├── simulated-collision.md # row 10
│ │ ├── compression.md # row 11
│ │ └── bottom-impact.md # row 12 🆕
│ ├── environmental/
│ │ ├── damp-heat-cycling.md # row 13
│ │ ├── immersion.md # row 14
│ │ ├── temperature-shock.md # row 15
│ │ ├── salt-fog.md # row 16
│ │ └── high-altitude.md # row 17
│ ├── electrical/
│ │ ├── over-temperature.md # row 18
│ │ ├── over-current.md # row 19
│ │ ├── external-short-circuit.md # row 20
│ │ ├── overcharge.md # row 21
│ │ └── over-discharge.md # row 22
│ └── thermal-stability/
│ ├── external-fire.md # row 23
│ └── thermal-propagation.md # row 24 ⭐
└── all-tests-at-a-glance.md # this page