As an engineer who follows the maintenance, testing, and lifecycle management of electric vehicle battery pack systems, I see the electric vehicle battery pack as far more than a single component. In my assessment, the electric vehicle battery pack is the central energy asset of a new energy vehicle, and its operational safety and performance stability directly determine vehicle safety and user experience. With the large-scale deployment of high-nickel ternary cathodes, lithium iron phosphate chemistries, and semi-solid-state cells, together with the rapid spread of cell-to-pack and cell-to-chassis integration and 800 V high-voltage fast-charging platforms, the applicable boundary of traditional repair specifications is narrowing. Many current repair standards cover only basic disassembly, high-voltage protection, and shallow operations. Deep repair lacks quantitative decision criteria, which leads to non-standard work, misdiagnosis, excessive replacement of the electric vehicle battery pack, and persistently high repair costs. In my view, the accelerating release of repair demand and the insufficient supply of standards have become a visible contradiction. For this reason, I argue that innovation in repair technical standards for the electric vehicle battery pack is urgent and necessary to unify workflows, reduce safety hazards, and improve resource utilization across the full lifecycle of the electric vehicle battery pack.
I begin from a practical observation: the electric vehicle battery pack is no longer a simple modular assembly. It is increasingly a structural, thermal, electrical, and digital system. Repair standards for the electric vehicle battery pack must therefore move from a parts-replacement logic to a system-repair logic. In the pages that follow, I summarize the current standard framework, identify core contradictions, and propose an innovation path. I use tables and formulas to make the analysis more quantitative and reusable. I repeatedly return to the electric vehicle battery pack because it is the object that connects safety, cost, warranty, insurance, recycling, and customer trust.
Current foundation of repair standards for the electric vehicle battery pack. I see a preliminary national framework that covers repair qualifications, operating procedures, and completion inspection. For example, GB/T 16739-2023, which took effect on April 1, 2024, introduced specific requirements for personnel, equipment, and sites for electric vehicle repair. In my reading, it requires repair enterprises to be equipped with insulation testing, safety protection, and explosion-proof equipment, and to establish a high-voltage safety operation assessment system. This provides a unified basis for market access related to the electric vehicle battery pack. Two key standards issued at the end of 2024 further refined operational norms. GB/T 44510-2024, on repair and maintenance technical requirements for new energy vehicles, specifies full-process repair items and high-voltage safety control requirements for intelligent battery systems. GB/T 45099-2024, on technical conditions for completion and delivery of power battery repair, unifies standardized processes for electric vehicle battery pack disassembly and assembly, cell opening, sealing and packaging, and factory performance testing. Together, these standards fill the gap in the completion stage. I believe they collectively build a basic institutional framework for electric vehicle battery pack repair.
High-voltage safety standards for the electric vehicle battery pack. The high-voltage system of an electric vehicle battery pack commonly reaches several hundred volts or even more than one thousand volts, far above the human safety voltage threshold. Electric shock and thermal runaway risks are prominent during repair. Safety standards therefore become the center of gravity. GB/T 47439-2026, on safety requirements for new energy vehicle repair operations, took effect on August 1, 2026. It establishes a two-person collaborative high-voltage repair system and makes quantitative provisions for pre-work risk screening, high-voltage power-down, and static discharge. It explicitly requires that after disconnecting the maintenance switch, the electric vehicle battery pack must remain static for 10 to 15 minutes, and residual voltage release must be confirmed before disassembly. The companion standard GB/T 47136-2026, on assessment specifications for health and safety status of pure electric vehicle power batteries, constructs a two-dimensional assessment system based on SOH health status and SOS safety status using operational data. It unifies indicator calculation models, assessment processes, and risk grading rules, moving safety control forward into fault diagnosis. I find that safety-specific standards and repair process standards are mutually connected, forming an operational framework of assessment first, repair second, and full-process protection.
Local and industry standards as supplements. I observe that different regions issue differentiated local standards based on local electric vehicle ownership and repair industry layout, forming a complementary standard system. Some local specifications quantify repair site and staffing requirements. For example, some classify battery repair zones, require a minimum area for first-class and second-class repair enterprises, and define skill levels for battery repair technicians. Other local standards bring electric vehicle repair safety management into local standard development, building a safety management framework around sites, protection, dismantling, storage, and emergency response. At the industry level, GB/T 45653-2025, on after-sales service specifications for new energy vehicles, extends repair technical requirements to the entire after-sales chain. I conclude that local standards focus on regional implementation details, while national standards unify underlying technical requirements. The two together promote the implementation of repair standardization for the electric vehicle battery pack.
| Standard layer | Primary function | Typical coverage | Gap I identify for the electric vehicle battery pack |
|---|---|---|---|
| Mandatory national standards | Safety bottom line | Electrical safety, battery safety, basic protection | Limited quantitative repair procedures for the electric vehicle battery pack |
| Recommended national standards | General technical rules | Repair qualifications, maintenance requirements, completion inspection | Weak coverage of module-level and cell-level repair |
| Industry association standards | Supplementary detail | After-sales service, digital operation, testing methods | Inconsistent terminology and thresholds across documents |
| Local standards | Regional implementation | Site area, personnel, safety management | Fragmented rules and uneven enforcement |
| Enterprise internal standards | Product-specific control | BMS parameters, sealing, proprietary diagnostics | Closed access and limited third-party applicability |
Why standards innovation for the electric vehicle battery pack is difficult. I identify four core contradictions. The first is poor vertical and horizontal connection among multi-level standards. Existing repair standards for the electric vehicle battery pack are divided into mandatory national standards, recommended national standards, group standards, local standards, and enterprise internal specifications. However, these levels lack overall coordination. Vertically, national standards focus on framework and principle requirements and lack quantitative operating details for module repair, cell repair, and other subdivided scenarios. They are difficult to use as detailed technical guidance for frontline work. Enterprise standards are often open only to authorized after-sales systems, and their technical parameters and repair processes are exclusive. They are difficult to adapt to independent third-party repair institutions. There is also a lack of transitional group standards between national standards and enterprise standards, creating a standard fault line. Horizontally, different standards define terminology, fault detection thresholds, and safety judgment scales inconsistently. Repair loss assessment and accident liability determination lack a unique basis, and standard conflicts occur frequently. High-voltage safety, fault diagnosis, repair processes, factory acceptance, and waste battery recycling are formulated independently. Their process nodes are disconnected, which leads to excessive execution flexibility and weakened binding force.
| Contradiction | Manifestation in electric vehicle battery pack repair | Consequence | Direction I propose |
|---|---|---|---|
| Vertical disconnection | National standards are too general; enterprise standards are too closed | No bridge for third-party repair of the electric vehicle battery pack | Create group standards for deep repair scenarios |
| Horizontal conflict | Different terms, thresholds, and safety scales | Inconsistent loss assessment and liability | Unify terms, thresholds, and decision indicators |
| Process fragmentation | Safety, diagnosis, repair, acceptance, recycling are separate | Weak full-chain traceability for the electric vehicle battery pack | Build an integrated process standard matrix |
| Weak enforceability | Recommended standards lack mandatory binding | Uneven adoption in independent repair markets | Link qualifications and insurance to standards |
Deep repair gaps for the electric vehicle battery pack. I find that existing standards mainly cover appearance inspection, overall disassembly and assembly, and basic high-voltage protection. For integrated batteries and cell-level repair, many regulatory blanks remain. The first gap is the lack of fault grading criteria. For high-frequency faults such as shell deformation in CTP or CTC electric vehicle battery pack designs, excessive cell voltage difference, and minor thermal damage, there is no unified quantitative index for three-level judgment: repairable, limited repair, and mandatory replacement. Disposal results depend heavily on individual experience, which easily causes excessive replacement of the electric vehicle battery pack and repair disputes. The second gap is insufficient refined process specifications. Core procedures such as cell consistency balancing repair, BMS underlying parameter calibration, integrated electric vehicle battery pack sealing reconstruction, and thermal management loop repair lack unified operation standards. Different institutions also differ in repair processes, and post-repair stability is difficult to guarantee. The third gap is weak long-term completion verification. GB/T 45099-2024 only specifies basic performance test items after repair. It does not establish standardized methods for cycle life prediction, long-term thermal runaway retesting, and multi-condition durability testing. Therefore, the long-term safety of a repaired electric vehicle battery pack cannot be evaluated. The fourth gap is the absence of intelligent repair standards. Big data health assessment, AI fault diagnosis, and cloud full-lifecycle traceability have been applied at scale, but supporting standards for data collection, algorithm models, and diagnostic processes have not yet been issued. Digital repair of the electric vehicle battery pack is in a state of no rules to follow.
| Deep repair scenario | Missing standard element | Risk for the electric vehicle battery pack | Quantitative indicator I recommend |
|---|---|---|---|
| CTP/CTC shell deformation | Deformation threshold and repair limits | Structural weakening and sealing failure | Maximum deformation, crack length, intrusion depth |
| Cell voltage imbalance | Voltage difference grading and balancing process | Capacity loss and local overheating | \(\Delta V_{cell}\), self-discharge rate, internal resistance dispersion |
| Minor thermal damage | Post-thermal event repair criteria | Delayed thermal runaway | Insulation resistance, leakage current, temperature rise rate |
| BMS parameter calibration | Access rights and calibration procedure | Incorrect SOC and SOH estimation | SOC error, SOH error, fault code consistency |
| Sealing reconstruction | Leak test pressure and duration | Moisture ingress and short circuit | Pressure decay, helium leak rate, IP rating verification |
| Thermal management loop | Flow, pressure, and coolant standards | Poor cooling and thermal imbalance | Flow rate, pressure drop, coolant conductivity |
Technical information barriers around the electric vehicle battery pack. I argue that core repair data for the electric vehicle battery pack are controlled by vehicle manufacturers and battery producers, forming a difficult technical barrier that restricts the implementation of unified standards. Key information such as internal battery structure drawings, BMS communication protocols, dedicated diagnostic programs, and original performance thresholds is open only to brand-authorized service systems. Third-party repair institutions cannot obtain a complete database. They often can only adopt the coarse model of replacing the entire electric vehicle battery pack. Module-level and cell-level refined repair are difficult to carry out compliantly. From the standard-setting perspective, unified repair standards require collaboration among vehicle manufacturers, battery enterprises, third-party repair institutions, insurance companies, and testing institutions. However, many vehicle manufacturers have insufficient willingness to open core repair technical specifications due to after-sales interests. Different enterprises have incompatible battery packaging schemes, electronic control communication protocols, and hardware interfaces. Differentiated product designs further increase the difficulty of formulating unified standards and continuously widen the technical capability gap between authorized systems and third-party institutions. This affects the high-quality development of digital repair for the electric vehicle battery pack.
| Information category | Current access | Impact on electric vehicle battery pack repair | Openness option I propose |
|---|---|---|---|
| Internal structure drawings | Authorized only | Third parties cannot plan safe disassembly | Tiered release of non-proprietary geometry |
| BMS communication protocol | Authorized only | Diagnosis and calibration are blocked | Standardized diagnostic interface and basic parameter set |
| Dedicated diagnostic software | Authorized only | Independent repair cannot read fault codes | Common data format and read-only access |
| Original performance thresholds | Authorized only | No baseline for repair vs replace decisions | Publish minimum safety and performance thresholds |
| Repair history records | Fragmented | Lifecycle traceability is incomplete | Cloud-based unique battery identity |
Standard update lag behind electric vehicle battery pack technology. I observe that the iteration speed of the electric vehicle battery pack is faster than the standard development and revision cycle. Current specifications are increasingly less compatible with mass-produced new technologies. From traditional MTP module solutions to CTP module-free electric vehicle battery pack designs, then to CTC battery-chassis integration, and to 800 V high-voltage fast charging and semi-solid-state batteries, highly integrated batteries and ultra-high-voltage systems lack specialized standards for disassembly, testing, and repair. At the same time, the complete cycle of a national standard from project initiation, drafting, public consultation, review, to release generally exceeds one year. Complex standards can take two to three years. However, the update cycle of battery materials, packaging structures, and electronic control schemes is often within one year. The lag in standard updates means that many new repair scenarios lack standard support, and some current clauses are disconnected from mainstream products. I therefore recommend a dynamic pre-research mechanism rather than a purely reactive revision model.
| Technology generation | Typical electric vehicle battery pack feature | Repair challenge | Standard lag risk |
|---|---|---|---|
| MTP modular | Replaceable modules and standard interfaces | Module-level repair is feasible | Low |
| CTP | Cell-to-pack integration | Cell removal and sealing are difficult | Medium to high |
| CTC | Cell-to-chassis structural integration | Vehicle structural repair and battery repair overlap | High |
| 800 V platform | Ultra-high-voltage fast charging | Insulation, arcing, and safety thresholds change | High |
| Semi-solid-state | New electrolyte and cell architecture | Unknown failure modes and repair limits | Very high |
Quantitative basis for repair decisions on the electric vehicle battery pack. In my view, the lack of quantitative decision models is one of the most practical reasons for excessive replacement. A repair decision should not be based only on visual inspection or a single fault code. It should combine state of health, state of safety, economic cost, and residual risk. I propose a multi-factor decision model. Let \(SOH\) be the state of health, \(SOS\) the state of safety, \(C_{repair}\) the direct repair cost, and \(C_{risk}\) the expected risk cost. A simplified repair priority index can be expressed as:
$$ RPI = \frac{SOH_{post} \cdot SOS_{post}}{C_{repair} + C_{risk}} $$
where \(SOH_{post}\) and \(SOS_{post}\) are the predicted health and safety states after repair. When \(RPI\) exceeds a threshold, repair is preferred. When it falls below the threshold, replacement or retirement of the electric vehicle battery pack should be considered. The direct repair cost can be decomposed as:
$$ C_{repair} = C_{diagnosis} + C_{labor} + C_{parts} + C_{downtime} + C_{equipment} $$
The expected risk cost can be modeled as:
$$ C_{risk} = P_{failure} \cdot L_{failure} + P_{thermal} \cdot L_{thermal} + P_{warranty} \cdot L_{warranty} $$
Here \(P_{failure}\), \(P_{thermal}\), and \(P_{warranty}\) are probabilities of functional failure, thermal event, and warranty claim after repair of the electric vehicle battery pack. \(L\) terms represent corresponding loss magnitudes. This model can be calibrated with field data. It allows repair institutions, insurers, and regulators to use a common language when deciding whether to repair or replace the electric vehicle battery pack.
Health and safety indicators for the electric vehicle battery pack. I use SOH and SOS as core indicators. A common SOH definition is:
$$ SOH = \frac{C_{current}}{C_{rated}} \times 100\% $$
where \(C_{current}\) is the current usable capacity and \(C_{rated}\) is the rated capacity of the electric vehicle battery pack. For safety, I propose a weighted SOS model:
$$ SOS = w_1 \frac{\Delta V_{cell}}{\Delta V_{limit}} + w_2 \frac{T_{max}}{T_{limit}} + w_3 \frac{R_{ins,min}}{R_{ins}} + w_4 \frac{\Delta T}{\Delta T_{limit}} $$
with the normalization condition:
$$ \sum_{i=1}^{4} w_i = 1 $$
In this formula, \(\Delta V_{cell}\) is the maximum cell voltage difference, \(T_{max}\) is the maximum observed temperature, \(R_{ins}\) is insulation resistance, and \(\Delta T\) is temperature dispersion within the electric vehicle battery pack. The weights \(w_i\) can be determined by expert scoring, failure statistics, or machine learning. A higher SOS value indicates a safer state. A lower SOS value triggers more restrictive repair conditions or mandatory replacement. I also recommend using voltage difference directly:
$$ \Delta V_{cell} = \max(V_i) – \min(V_i) $$
and insulation resistance:
$$ R_{ins} = \frac{V_{test}}{I_{leak}} $$
These formulas are simple enough for field use and can be embedded in digital diagnostic tools for the electric vehicle battery pack.
| Indicator | Formula or definition | Purpose in electric vehicle battery pack repair | Suggested action threshold |
|---|---|---|---|
| SOH | \(SOH = C_{current}/C_{rated}\) | Capacity and aging assessment | Below 70% triggers detailed evaluation |
| SOS | Weighted multi-factor index | Safety state screening | Below 0.6 triggers restricted repair |
| Cell voltage difference | \(\Delta V_{cell} = \max(V_i) – \min(V_i)\) | Consistency and imbalance detection | Above 100 mV triggers balancing or repair |
| Insulation resistance | \(R_{ins} = V_{test}/I_{leak}\) | Electric shock risk | Below 500 \(\Omega\)/V triggers isolation |
| Temperature dispersion | \(\Delta T = T_{max} – T_{min}\) | Thermal management fault | Above 8 °C triggers thermal loop inspection |
| Round-trip efficiency | \(\eta_{round} = E_{discharge}/E_{charge}\) | Energy loss assessment | Below 90% triggers diagnosis |
Thermal safety formulas for the electric vehicle battery pack. I consider thermal risk to be a central concern in deep repair. A first-order thermal model can estimate temperature rise after a repair that may have altered thermal paths:
$$ T(t) = T_{amb} + P_{loss} R_{th} (1 – e^{-t/\tau}) $$
where \(T_{amb}\) is ambient temperature, \(P_{loss}\) is heat generation power, \(R_{th}\) is thermal resistance, and \(\tau = R_{th} C_{th}\) is the thermal time constant. The accumulated thermal energy is:
$$ E_{thermal} = \int_{0}^{t} P_{loss}(t) dt $$
For a liquid-cooled electric vehicle battery pack, the heat removed by coolant can be approximated as:
$$ Q_{cool} = \dot{m} c_p \Delta T $$
where \(\dot{m}\) is mass flow rate, \(c_p\) is specific heat capacity, and \(\Delta T\) is coolant temperature rise. If \(Q_{cool}\) is insufficient relative to \(P_{loss}\), the electric vehicle battery pack may develop local hot spots. I therefore propose that repair completion standards for the electric vehicle battery pack should include thermal resistance and coolant flow verification, not only static voltage and insulation tests.
Proposed innovation path 1: a hierarchical and coordinated standard system for the electric vehicle battery pack. I propose building a multi-level system with mandatory national standards as the bottom line, recommended national standards for general rules, group standards for subdivided scenarios, and enterprise standards for detailed control. Vertically, mandatory national standards such as GB 18384-2025 and GB 38031-2025 should serve as the safety bottom line. They should unify general repair terminology, minimum safety thresholds, general test methods, and basic completion requirements for the electric vehicle battery pack. Industry associations should develop group standards focused on module repair, cell balancing, CTP/CTC electric vehicle battery pack inspection, and BMS calibration. Vehicle and battery enterprises should be encouraged to create internal specifications stricter than national standards. General enterprise technical specifications should be transformed into group or national standards to fill operational gaps. Horizontally, I recommend synchronizing five areas: repair safety, fault diagnosis, refined processes, environmental disposal of waste batteries, and factory acceptance. Cross-standard terminology, detection thresholds, and judgment indicators should be unified to eliminate conflicts and form an integrated framework covering the full repair process of the electric vehicle battery pack.
| Level | Standard type I propose | Focus for the electric vehicle battery pack | Example content |
|---|---|---|---|
| Bottom line | Mandatory national standard | Electrical safety, thermal safety, minimum protection | Insulation limits, high-voltage isolation, thermal propagation |
| General | Recommended national standard | Terminology, diagnosis flow, completion inspection | SOH/SOS assessment, fault code mapping, acceptance tests |
| Subdivided | Group standard | Module repair, cell balancing, CTP/CTC repair | Cell replacement, sealing, BMS calibration |
| Detailed | Enterprise standard | Product-specific parameters and tools | Torque values, coolant type, proprietary diagnostics |
| Regional | Local standard | Site, personnel, emergency response | Repair zone area, training, fire protection |
Proposed innovation path 2: digital repair supporting standards for the electric vehicle battery pack. I argue that digitalization is not optional. It is a prerequisite for consistent, traceable, and scalable repair of the electric vehicle battery pack. I propose using existing foundations such as digital twin specifications and battery coding rules to accelerate digital standards. First, a unified digital inspection and assessment specification should define data collection devices, sampling frequency, and accuracy thresholds for voltage, internal resistance, temperature, and cell voltage difference. It should unify a general SOH calculation model to provide a consistent data baseline for AI fault diagnosis and cloud health assessment of the electric vehicle battery pack. Second, a full-lifecycle repair data standard should regulate data formats and storage requirements for fault detection, repair operations, cell repair parameters, and completion reports. This enables full traceability from incoming diagnosis to repair delivery for each electric vehicle battery pack. Third, a repair data interaction standard should define the basic data scope that vehicle manufacturers must open to third-party institutions, clarify transmission encryption and information security requirements, and break down information barriers while protecting intellectual property.
| Digital standard area | Required data fields | Benefit for the electric vehicle battery pack | Implementation priority |
|---|---|---|---|
| Inspection data | Voltage, current, temperature, internal resistance, insulation | Consistent fault diagnosis | High |
| Repair process data | Disassembly steps, torque, seal pressure, calibration values | Repeatable and auditable repair | High |
| Cell repair data | Cell ID, capacity, resistance, self-discharge rate | Consistency control | Medium to high |
| Completion data | SOH, SOS, thermal test, leak test, road test | Long-term safety confidence | High |
| Traceability data | Unique battery ID, repair history, warranty status | Lifecycle management and recycling | High |
| Security data | Access logs, encryption keys, user roles | Data protection and liability | Medium |
Proposed innovation path 3: a dynamic update and pre-research mechanism for electric vehicle battery pack standards. I recommend a problem-oriented mechanism of annual evaluation, early pre-research, and industry-academia-research collaboration. First, an annual standard evaluation system should be implemented. The standardization authority, together with industry associations and testing institutions, should conduct annual applicability assessments of current repair standards. They should identify clauses disconnected from new technologies and regulatory blanks, and form an annual revision list. For frontier products such as semi-solid-state batteries, CTC integrated chassis batteries, and 800 V ultra-high-voltage platforms, pre-research should start early. Pilot cities can be selected for practical repair verification. Once the technology reaches scale, results can be quickly converted into national standards, shortening the lag cycle. Second, a collaborative standard research platform should be built. The government should coordinate universities, research institutes, vehicle and battery enterprises, third-party repair chains, testing and certification bodies, and insurance institutions to participate in drafting. This integrates technical, operational, and market resources across the industrial chain, improves the forward-looking nature, comprehensiveness, and feasibility of standards, and synchronizes dynamic revision with electric vehicle battery pack technology iteration.
| Mechanism | Frequency | Input | Output for the electric vehicle battery pack |
|---|---|---|---|
| Annual applicability review | Every year | Field failures, repair data, technology trends | Revision list and gap report |
| Pre-research project | Before mass deployment | Prototype tests, pilot repair data | Draft standard for new electric vehicle battery pack designs |
| Collaborative drafting | Continuous | Industry, academia, repair, insurance | Balanced and practical standard text |
| Fast-track conversion | When technology scales | Validated pilot results | Timely national or group standard |
| Feedback loop | Post-implementation | Compliance data, accident data, cost data | Targeted amendment |
Proposed innovation path 4: full-chain supervision for electric vehicle battery pack repair. I believe standards only create value when they are executed. A complete supervision mechanism should be established across access, personnel, regulation, and traceability. First, repair qualifications should be mandatorily linked to standards. Safety requirements and completion technical conditions for the electric vehicle battery pack should be included as hard indicators in enterprise business qualification review. Those that do not meet the requirements should not receive special qualification for electric vehicle battery pack repair. Second, the standardized training and assessment system for practitioners should be improved. Layered training should cover new battery structures, digital diagnostic equipment, and updated standards. A certified high-voltage repair technician system should be established, with standard execution ability as a core assessment indicator. Third, a multi-agent collaborative supervision mechanism should be built. Market regulators, third-party testing institutions, and vehicle insurance enterprises should uniformly adopt current technical standards as the basis for quality spot checks, accident tracing, and loss assessment. This eliminates differences in execution scales. Fourth, a closed loop for repair quality complaints and accident tracing should be established. Relying on digital archives for the electric vehicle battery pack, special inspections should be conducted for illegal dismantling and simplified safety procedures. Measures should range from warnings and rectification to revocation of special qualifications. Full-process supervision can thus guarantee the implementation of standards.
| Supervision dimension | Action | Standard linkage | Expected effect on the electric vehicle battery pack |
|---|---|---|---|
| Access | Qualification review | Safety and completion standards | Remove unqualified repair providers |
| Personnel | Certified high-voltage technician system | Training and assessment standards | Reduce human error |
| Regulation | Joint spot checks and loss assessment | Diagnosis and acceptance standards | Unify enforcement scale |
| Traceability | Digital archive and complaint closure | Data and coding standards | Enable accountability |
| Insurance | Standard-based claims and pricing | Safety and SOH/SOS standards | Reduce excessive replacement |
Economic and environmental effects of standard innovation for the electric vehicle battery pack. I expect that better standards will change the economics of repair. Today, excessive replacement of the electric vehicle battery pack is common because repair institutions lack confidence in deep repair. With quantitative criteria, more electric vehicle battery pack units can be repaired at module or cell level. This reduces customer cost and insurance loss. It also preserves the embedded energy and materials in the electric vehicle battery pack. I propose a lifecycle cost model:
$$ LCC = C_{initial} + \sum_{t=1}^{n} \frac{C_{O\&M,t} + C_{repair,t}}{(1+r)^t} $$
where \(C_{initial}\) is initial acquisition cost, \(C_{O\&M,t}\) is operation and maintenance cost in year \(t\), \(C_{repair,t}\) is repair cost, and \(r\) is discount rate. Standardized repair can reduce \(C_{repair,t}\) and extend the useful life \(n\) of the electric vehicle battery pack. The environmental benefit can be approximated by avoided manufacturing impact:
$$ E_{avoided} = M_{battery} \cdot I_{material} + E_{manufacturing} $$
where \(M_{battery}\) is battery mass, \(I_{material}\) is material impact intensity, and \(E_{manufacturing}\) is manufacturing energy. When a repair avoids replacement of the whole electric vehicle battery pack, these impacts are deferred or avoided. I therefore see standard innovation as both an economic and environmental instrument.
| Effect area | Without standard innovation | With standard innovation | Impact on the electric vehicle battery pack |
|---|---|---|---|
| Repair cost | High due to replacement bias | Lower through module and cell repair | Reduced total cost of ownership |
| Safety | Variable and experience-based | Quantitative and auditable | Fewer thermal and electrical incidents |
| Resource use | Premature recycling | Extended service life | Higher material utilization |
| Market trust | Uncertain repair quality | Traceable and certified repair | Stronger customer confidence |
| Insurance | High loss ratio and disputes | Standard-based loss assessment | Faster claims and fair pricing |
Implementation roadmap I propose. I recommend a phased roadmap. In the first phase, terminology, fault codes, and basic safety thresholds for the electric vehicle battery pack should be unified. In the second phase, deep repair group standards for module, cell, BMS, sealing, and thermal management should be developed. In the third phase, digital data formats and interface standards should be issued. In the fourth phase, supervision and insurance linkage should be strengthened. A roadmap can be expressed as a weighted progress index:
$$ P_{roadmap} = \alpha_1 P_{terminology} + \alpha_2 P_{deep} + \alpha_3 P_{digital} + \alpha_4 P_{supervision} $$
with:
$$ \sum_{i=1}^{4} \alpha_i = 1 $$
I would assign higher initial weights to terminology and deep repair because they directly affect daily work on the electric vehicle battery pack. Digital and supervision weights can increase over time. This roadmap helps avoid isolated standard development and keeps the focus on practical repair of the electric vehicle battery pack.
| Phase | Main task | Key deliverable | Success indicator for the electric vehicle battery pack |
|---|---|---|---|
| Phase 1 | Unify terms and thresholds | Common diagnosis language | Reduced disputes over fault grading |
| Phase 2 | Develop deep repair standards | Group standards for modules and cells | Higher module-level repair rate |
| Phase 3 | Build digital standards | Data format and interface rules | Traceable repair records |
| Phase 4 | Link supervision and insurance | Qualification and claims linkage | Lower excessive replacement rate |
Risk management for standard innovation. I also recognize risks. If standards are too strict, they may slow repair and increase costs. If they are too loose, safety may be compromised. I propose a risk-based tiered approach. Low-risk operations such as external inspection and connector replacement can follow simplified rules. Medium-risk operations such as module replacement and coolant loop repair require certified technicians and diagnostic records. High-risk operations such as cell opening, BMS calibration, and sealing reconstruction require enhanced supervision and post-repair verification. A risk score can be defined as:
$$ Risk = Severity \times Probability \times Detection $$
This is analogous to failure mode and effects analysis. For the electric vehicle battery pack, severity may reflect thermal runaway consequence, probability may reflect failure likelihood, and detection may reflect difficulty of identifying the fault. Standards should require stronger controls when \(Risk\) exceeds a defined threshold. This allows flexibility without sacrificing safety.
| Risk level | Example operation on the electric vehicle battery pack | Required control | Verification method |
|---|---|---|---|
| Low | Visual inspection, connector check | Basic training and PPE | Checklist and function test |
| Medium | Module replacement, coolant service | Certified technician, two-person rule | Insulation, leak, and thermal test |
| High | Cell opening, BMS calibration, sealing | Special qualification, supervisor approval | Full SOH/SOS assessment and durability test |
| Extreme | Damaged high-voltage pack with thermal event | Emergency response and isolation | Remote monitoring and destructive analysis if needed |
Key performance indicators for the standard system. I suggest measuring the success of standard innovation with clear indicators. These include repair rate at module level, excessive replacement rate, repair-related accident rate, average repair cost, average turnaround time, traceability coverage, and customer satisfaction. For the electric vehicle battery pack, the excessive replacement rate is especially important. It can be defined as:
$$ ERR = \frac{N_{replace, excessive}}{N_{replace, total}} \times 100\% $$
A lower \(ERR\) indicates better diagnostic and repair capability. The module-level repair rate can be defined as:
$$ MRR = \frac{N_{module repair}}{N_{repair, total}} \times 100\% $$
Higher \(MRR\) suggests that standards are enabling deeper repair. I also propose a data openness index:
$$ DOI = \frac{N_{open}}{N_{required}} \times 100\% $$
where \(N_{open}\) is the number of required data items actually accessible to third-party institutions, and \(N_{required}\) is the total required for safe repair of the electric vehicle battery pack. These indicators can guide policy adjustment.
| KPI | Definition | Target direction | Relevance to the electric vehicle battery pack |
|---|---|---|---|
| Excessive replacement rate | \(ERR = N_{replace, excessive}/N_{replace, total}\) | Decrease | Reduces waste and cost |
| Module repair rate | \(MRR = N_{module repair}/N_{repair, total}\) | Increase | Shows deep repair maturity |
| Data openness index | \(DOI = N_{open}/N_{required}\) | Increase | Breaks information barriers |
| Repair safety incident rate | Incidents per 1,000 repairs | Decrease | Protects technicians and users |
| Traceability coverage | Repaired packs with digital records | Increase | Supports lifecycle management |
| Average repair cost | Total cost per repair | Decrease | Improves affordability |
My final assessment. In my first-person assessment, the electric vehicle battery pack is the decisive object in the new energy vehicle aftermarket. Standard innovation for its repair is not a purely technical task. It is an institutional, digital, economic, and safety task. The current framework has made progress in qualifications, high-voltage safety, and completion inspection. However, it still lacks deep repair rules, quantitative thresholds, data openness, and dynamic updating. I have proposed a four-path approach: a hierarchical and coordinated standard system, digital repair supporting standards, a dynamic update and pre-research mechanism, and full-chain supervision. I have also proposed formulas for SOH, SOS, repair priority, thermal safety, lifecycle cost, and performance indicators. These tools can help transform repair decisions for the electric vehicle battery pack from experience-based to evidence-based. If implemented, they can reduce excessive replacement, improve safety, extend service life, and support green and high-quality development of the electric vehicle battery pack industry. I conclude that the electric vehicle battery pack repair standard system must be built as a living system, continuously learning from field data, technology iteration, and market feedback. Only then can it serve the electric vehicle battery pack throughout its full lifecycle and give users, repair institutions, insurers, and regulators a shared and reliable foundation.