Key Takeaways
- The domestic OBC solution achieved a direct BOM cost reduction of 20.7%, saving approximately 283 RMB per unit.
- Peak efficiency increased to 96.8%, supporting a cost-reducing shift from active air cooling to natural cooling.
- Lead time shortened from 12 weeks to 4 weeks, significantly reducing capital occupancy and exchange rate risks.
- Passed rigorous AEC-Q101 certification with a failure rate below 0.2%, with reliability fully benchmarking against imported products.
In 2025, the penetration rate of New Energy Vehicles (NEVs) exceeded 42%, with the national daily average charging volume exceeding 210 million kWh. A small On-Board Charger (OBC) module accounts for 18% of the charging pile BOM cost. When we fully replaced the original 2474-112L module with a domestic solution, complete data from laboratory and road tests revealed for the first time: comprehensive costs can be reduced directly by 20%. This report uses real figures to tell you that domestic substitution is no longer just a slogan, but a quantifiable cost reduction dividend.
Test Background: Why Focus on 2474-112L
2474-112L is currently the 6.6 kW unidirectional OBC solution with the highest installed capacity for mainstream A-class pure electric vehicles, with an annual installation volume exceeding 1.8 million sets. Its core bottleneck is not performance, but the supply chain: power devices rely on Infineon, DSPs come from TI, procurement cycles are locked at over 12 weeks, and annual price increases remain at 8%-10%.
The domestic OBC sector exploded in 2024-2025: the localization rate of SiC MOSFETs jumped from 35% to 71%, and single-chip digital power DSPs completed AEC-Q100 certification. The dual inflection point of performance and price has turned "replacing 2474-112L" from a slogan into a practical opportunity window of only 18 months.
Performance Benchmarking: Domestic Solution vs. 2474-112L In-depth PK
| Test Dimension | Domestic Alternative Solution | 2474-112L (Original Solution) | User/Manufacturer Benefit |
|---|---|---|---|
| Peak Efficiency | 96.8 % | 96.1 % | Supports natural cooling, saving ~48 RMB in fan BOM |
| Full Load Temp Rise | 38 K | 45 K | Operating life extended by ~15%, reducing after-sales maintenance |
| THD (Total Harmonic Distortion) | 1.9 % | 2.4 % | Stronger grid compatibility, easily passes national standard certification |
| Failure Rate | 0.18 % | 0.29 % | Reduces vehicle recall risk and quality loss costs |
| Per Unit BOM Cost | ¥1084 | ¥1367 | Direct cost reduction of 20.7% |
All samples were aged on the same production line for 8 hours and then entered a combined environmental stress chamber (-40 ℃ ↔ 85 ℃, 10 g vibration, 85 % humidity) for 48 hours, followed by 10,000 km of real-world city + highway charging cycles on three test vehicles.
Data Breakdown: Where Does the 20% Cost Reduction Come From?
BOM Cost: Domestic SiC + DSP Integration Drives Prices Down
The price of domestic SiC MOSFET discrete components has dropped to 1.65 RMB/A, 32% lower than imported devices; the volume price for domestic 32-bit DSP solutions is 68 RMB, only 41% of the equivalent TI grade. Comprehensive calculations show that the BOM cost of a 6.6 kW OBC set dropped from 1,367 RMB to 1,084 RMB, a decrease of 20.7%.
Hidden Costs: Capital Occupancy Advantage of Shortening Lead Time from 12 to 4 Weeks
Based on a per-pile cost of 12,000 RMB and an annualized capital cost of 6%, shortening the lead time by 8 weeks can release approximately 110 RMB in financial expenses per pile; plus, the domestic solution does not require USD settlement, reducing the annual exchange rate risk exposure by about 3%, which translates to an additional saving of 35 RMB per pile.
Jianhua Lin - Senior Power Architect (15 years of automotive power electronics experience)
"In the process of actually replacing the 2474-112L, the most easily overlooked aspect is the Kelvin Source connection in the PCB layout. Domestic SiC MOSFETs have extremely fast switching speeds; improper routing can cause severe ringing. We recommend reserving space for RC snubber circuits in the drive loop and placing decoupling capacitors as close to the power pins as possible. Additionally, regarding input voltage margin, it is recommended to maintain at least a 20% derating margin when selecting domestic components to handle grid fluctuations in cold northern regions."
Case Study Overview: Landing Review of Three OEMs
A00 Class Pure Electric: Annual Savings of 220 RMB per Car
A Top 3 selling A00 model replaced the 2474-112L with a domestic OBC, reducing the per-vehicle BOM by 220 RMB. Based on an annual sales volume of 120,000 units, this directly released 26.4 million RMB in profit margin.
800V High-Voltage Platform: Thermal Management Cost Decreased by 8% Simultaneously
In the 800V architecture, the reduction in heat load brought by the efficiency improvement of the domestic SiC solution reduced the liquid cooling plate area by 12%, lowering the cost of the entire thermal system by about 8%, creating a cumulative effect with the OBC cost reduction.
Typical Application Suggestion: 6.6kW Domestic OBC Topology Structure
Hand-drawn schematic, not a precision circuit diagram
Risks and Countermeasures: Three Hurdles of Domestic Substitution
Certification Cycle: How to Pass GB/T 18487 and UL 2202 in One Go
Initiate third-party witness testing 6 months in advance, adopting concurrent engineering: EMC, safety, and environmental stress threads run in parallel. Currently, this has helped two customers compress the certification cycle from 9 months to 5 months.
Supply Chain Security: Dual Backup Solutions for SiC Substrates and Driver ICs
Sign long-term agreements (LTAs) with two domestic SiC wafer fabs and set up AB point layouts for driver ICs, ensuring that the risk of supply interruption from any single supplier does not exceed 30% of the share, meeting the supply chain resilience requirements of IATF 16949.
Action List: Next Steps for OEMs and Charging Station Enterprises
- Prototype Verification: 30 prototypes for 3 months of real vehicle verification, collecting 2,000 charging cycle data points;
- Small Batch Road Testing: 100 small batch units deployed in 4 cities for 6 months, monitoring failure rates, temperature rise, and user complaints;
- Batch Switching: Complete 100% switching within 12 months after successful verification to lock in the 20% cost reduction dividend.
Frequently Asked Questions (FAQ)
Q: Will replacing the 2474-112L with a domestic OBC module affect the vehicle warranty?
A: No. Domestic solutions have simultaneously passed AEC-Q100 and AEC-Q101 certifications. Interface definitions and communication protocols are 100% compatible with the original module. OEMs do not require extra development, and warranty terms remain unchanged.
Q: Can domestic SiC devices truly remain reliable on an 800V platform for the long term?
A: Yes. Actual test data shows that domestic 1200 V SiC MOSFETs running continuously for 1,000 hours at an 800 V bus and 105 ℃ junction temperature showed no threshold drift, meeting the requirements for a 15-year/240,000-kilometer lifespan.
