CINEVE | Three Core Technology Trends in New Energy Vehicle Maintenance: Understanding Industry Transformation

Driven by policy support, high-temperature operating conditions, and rapid iteration of high-voltage vehicle platforms, the new energy vehicle (NEV) maintenance sector is undergoing a concentrated technological transformation. The new policy issued by nine ministries and commissions fully liberalizes technical access to three-electric system maintenance, summer heat conditions are pushing precise thermal management diagnostics and repair, and the standardization of 800V high-voltage platform maintenance is accelerating. These three major technical trends run through the entire daily workflow of workshop maintenance services.

1. Policy Unlocks Core Three-Electric Maintenance Technology: “Repair Instead of Replace” Becomes Widely Adopted

Driven by the implementation of a new policy issued by nine ministries and commissions, automakers are now opening access to three-electric system diagnostic protocols, BMS low-level data, and battery pack disassembly standards to compliant repair facilities. The long-standing “black box” in automotive repair technology is being fundamentally dismantled. The mainstream transformation in workshop operations is shifting toward cell-level precision repair. In the past, when battery voltage deviation reached 75% or a single cell showed significant degradation, the entire battery pack had to be replaced. Today, with access to OEM technical parameters, technicians can apply active balancing, single-module replacement, and BMS software reflashing to restore faults. Repair costs are reduced to approximately 10%–30% of full pack replacement.

Core Technical Highlights

• Bi-directional Buck-Boost active balancing systems are used to control cell voltage deviation within a safe threshold of 0.05V

• OEM diagnostic tools enable accurate retrieval of SOH (State of Health) data to precisely identify degraded cells

• No full battery pack disassembly is required, enabling localized minimally invasive repair and significantly reducing high-voltage safety risks

The new policy clearly states that the use of such compliant repair technologies does not affect vehicle warranty coverage. As a result, three-electric precision repair orders increased by 40% week-on-week, becoming a key revenue driver for workshop technical services.

2. High Temperatures in Summer Drive Integrated Thermal Management Maintenance Technology, Addressing Both Range and Charging Failures

Under sustained high-temperature conditions, the battery system, electric drive system, and heat pump air-conditioning system share a unified liquid cooling architecture. As a result, thermal management failure has become the most common fault type this week. A standardized thermal system maintenance process has therefore become an essential skill for technicians.

2.1 Battery Thermal Management Maintenance Technology

For vehicles experiencing fast-charging cut-off, significant range reduction, or high-temperature warning alerts, a standardized four-step maintenance process is applied: High-pressure cleaning of condenser and removal of cotton fluff/debris Pressure testing for coolant pipeline leakage Vacuum filling of coolant system Calibration of temperature sensors Key inspection points include aging of thermal interface materials and hidden corrosion in the liquid cooling plate. These issues can lead to localized cell hotspots, which may trigger thermal runaway risks if not properly addressed.

2.2 Heat Pump Air-Conditioning High-Voltage Maintenance Process

Unlike traditional fuel vehicle air-conditioning systems, new energy high-voltage compressor faults must follow a “from electrical to mechanical” diagnostic logic: First check high-voltage insulation resistance Then verify drive board communication signals Next inspect refrigerant leakage and refrigerant oil deficiency The drive board can be repaired independently without replacing the entire compressor assembly, significantly reducing maintenance costs.

2.3 Electric Drive Cooling System Diagnosis Process

For motor overheating and power-limiting faults, the key inspection points include: Electronic water pump speed verification Cooling fan HVIL (High Voltage Interlock Loop) circuit inspection Vacuum replacement of antifreeze coolant to remove air from the system This process eliminates recurring overheating warnings and ensures stable thermal performance.

3. Standardization of 800V High-Voltage Platform Maintenance Accelerates: Urgent Need for Workshop Equipment and Technical Upgrades

The number of new 800V high-voltage vehicle models entering workshops continues to rise, making high-voltage safety inspection standards a key industry focus. Compared with 400V platforms, 800V systems operate at voltages up to 950V, placing significantly higher technical requirements on insulation, interlock systems, and BMS architecture during maintenance. 

Key Technical Changes 

• The insulation resistance testing standard during maintenance is raised to ≥20MΩ

• All service tools must pass dielectric withstand testing of no less than 2500V DC

• Diagnostic equipment must support a three-layer architecture high-voltage BMS system and enable CAN FD high-speed communication for module data reading

• High-voltage power-down procedures and HVIL (High Voltage Interlock Loop) inspection have become mandatory pre-maintenance steps

These requirements are essential to prevent electrical arcing, leakage risks, and other high-voltage safety hazards in workshop operations.

The three key maintenance technologies for new energy vehicles represent a fundamental industry shift from "component assembly replacement" to "precision diagnostics, targeted repairs, and standardized high-voltage servicing." Policy liberalization has broken down technical barriers for third-party repair shops; the demands of high-temperature operating conditions have necessitated refined thermal management diagnostics; and the evolution of high-voltage platforms has driven a dual upgrade in shop equipment and technician skills. For repair shops, mastering the three core technologies—cell balancing, comprehensive thermal management servicing, and 800V high-voltage safety—enables them to lower repair costs for owners and build a competitive edge through differentiation. For vehicle owners, the availability of these repair technologies means avoiding exorbitant costs for full assembly replacements due to minor faults; instead, precision repair solutions from compliant shops offer a balance between vehicle safety and cost-effectiveness.