Overview — the integrated 6 kW HV-DCDC tier in the new-energy power chain
The Youlai new-energy power-conversion family covers three tiers of HV-side DC-DC role on a modern electric commercial vehicle:
- Heavy-duty tier (36 kW continuous, 40 kW peak) — the EBX-2314 HV-DCDC controller for the main 24V auxiliary bus on an electric heavy truck or electric bus, where the auxiliary load (lighting, BCM, instrument cluster, cabin HVAC blowers, all low-voltage ECUs) can pull 20-30 kW at peak
- Mid-duty tier (6 kW continuous) — the EBX-2512, this product — sized for the auxiliary HV branch on a heavy-duty EV, the primary HV-DCDC on a mid-duty new-energy commercial vehicle, the HV-DCDC for an electric light truck / electric pickup programme
- Auxiliary tier (180 W continuous) — the EBX-2515 industrial DCDC module (24V-side step-down for a 12V isolated sub-system supply, not HV-side)
The EBX-2512 is the fully-integrated middle tier — not just a controller (like the EBX-2314), but the complete power stage + control + housing + dual-fan forced-air cooling in one package. The wide 400-1100 VDC input window covers the three mainstream traction-pack architectures in service on Chinese new-energy commercial vehicles (400 V class for compact and light platforms, 600 V class for medium platforms, 900 V class for heavy-duty and high-performance platforms), with the rated nominal voltage selectable at 600 V or 900 V per the host vehicle programme.
The 16-32 VDC output spans the 24V auxiliary-bus working window from cold-crank-low (16 V) to top-of-charge ceiling (32 V), centred on the rated 28 V which is the typical 24V auxiliary-bus nominal-charge level on a 24V system. 6 kW continuous output capability sizes the EBX-2512 for the secondary HV-DCDC role (auxiliary HV branch on a heavy-duty truck where the main DCDC handles the bulk load and the EBX-2512 handles a dedicated sub-circuit) or the primary HV-DCDC role on a mid-duty / light-duty programme (where 6 kW continuous covers the full auxiliary-bus load).
Engineering details
Wide HV input window for cross-platform compatibility
The 400 – 1100 VDC input window is one of the widest in the OEM-supplier landscape and covers all three mainstream traction-pack voltage classes used on Chinese new-energy commercial vehicles. A programme that goes from a 600 V mid-class platform to a 900 V high-performance platform across model years can keep the same DCDC supplier and (in many cases) the same DCDC unit, reducing the supplier-qualification effort across vehicle generations. The rated nominal is selectable at 600 VDC or 900 VDC — the OEM declares the rated input voltage at quotation so that the EMC / efficiency / thermal validation can be tied to the right working point.
Forced-air cooling with dual axial fans
6 kW of continuous power conversion at typical ≥ 90 % efficiency still produces ~600 W of thermal load that the housing has to shed. The EBX-2512 carries dual axial fans on the heat-sink top face for forced-air convection across the entire fin surface; the dual-fan arrangement gives airflow redundancy (one fan can fail and the unit still operates at de-rated power), and the dual-fan parallel arrangement keeps the per-fan working point in the high-efficiency / low-noise envelope. The source design notes mark the EBX-2512 as a "high heat-source device" that requires guaranteed cooling airflow and explicitly cautions against placing heat-sensitive parts close to the converter envelope. Horizontal mounting only.
High-voltage safety stack — GB 18384-2020 + 4480 V withstand
The HV safety stack matches the China-EV national-standard envelope:
- GB 18384-2020 high-voltage warning marking on the housing top face — the "高压危险" (HV danger) marking with the "维修请断电" (isolate before service) instruction. The lightning-bolt safety pictogram is positioned for visibility during the under-vehicle service routine
- SQB 10055 part-traceability marking on every unit — supports the OEM end-of-life recall traceability across the entire installed fleet
- DC 4480 V / 1 min (or AC 3200 V / 1 min) live-to-chassis withstand voltage with no breakdown and no arcing — comfortably above the 1.5-2.0× over-rating typical of the China-EV safety standard
- Leakage current ≤ 5 mA under the withstand test — safe for the standard isolation-monitor envelope used on Chinese EV high-voltage systems
- Insulation resistance ≥ 20 MΩ at 90 % relative humidity — the elevated-humidity profile is the worst-case envelope and the source qualification value is comfortably above the 20 MΩ floor
HV connector family — AVIC EP1 + Recodeal
The HV connector family is the China-EV industry-standard. AVIC Optoelectronics EP1-series connectors carry the 24V output positive (red key, EP1-112Z1K90-RE on the board side / EP1-112T1J90-RE on the harness side) and the 24V output negative (blue key, EP1-112Z1K135-BL on the board side / EP1-112T1J135-BL on the harness side). The keyed +/− pair eliminates the polarity-reversal failure mode during workshop assembly. The HV input is a Recodeal REL-Z2PNH-4-A 2-pin interlock connector for the traction-pack DC bus side.
The low-voltage 12-pin signal connector is a sealed Yonggui XC-F-M24 series with a deliberate 12-pin pin-out: pins 1-4 carry the 24V supply (dual-pin redundancy on the +24V and dual-pin redundancy on the GND for higher current capacity); pin 5 carries the key-ON / VCU wake-up; pins 6-7-8 carry the vehicle CAN bus (CAN1_H / CAN1_L / cable shield); pins 9-10 carry the 2-bit board ID-code lines (programme-side identification for the OEM auto-detection of the installed DCDC variant); pins 11-12 are reserved for internal-communication links.
Mechanical drawings — top, side and front views
High & low-voltage connector reference (table 1)
Low-voltage signal connector pin-out (table 2)
| Pin | Definition | Wire gauge | Function group |
|---|---|---|---|
| 1 | 24V+1 | 1.0 mm² | 24V supply rails (dual-pin redundancy on + and on −) |
| 2 | 24V+2 | 1.0 mm² | |
| 3 | 24V−1 | 1.0 mm² | |
| 4 | 24V−2 | 1.0 mm² | |
| 5 | Wake-up source | 1.0 mm² | Key-ON or VCU wake |
| 6 | CAN1_H | 1.0 mm² | Vehicle CAN bus |
| 7 | CAN1_L | 1.0 mm² | |
| 8 | CAN1 shield | 1.0 mm² | |
| 9 | ID-code 1 | 0.75 mm² | Board ID identification |
| 10 | ID-code 2 | 0.75 mm² | |
| 11 | Internal-comm 1 | 0.75 mm² | Internal communication |
| 12 | Internal-comm 2 | 0.75 mm² |
Comparison with the related Youlai HV power modules
| Model | Tier | HV input | Output | Cooling | Footprint |
|---|---|---|---|---|---|
| EBX-2314 | Heavy-duty controller | 600 VDC (400-750) | 18-32 VDC / 36 kW | Programme-spec (OEM-side power stage) | 200 × 500 × 200 mm |
| EBX-2512 | Mid-duty integrated converter | 400-1100 VDC (rated 600 / 900) | 16-32 VDC / 6 kW | Dual-fan forced air (IP68) | 344 × 244 × 114 mm |
| EBX-2514 | DC-AC inverter (VTL) | 400-1100 VDC (rated 600 / 900) | 220 VAC / 50 Hz / 30 kW | Quad-fan forced air (IP68) | 656 × 400 × 204 mm |
| EBX-2407 | 24V→12V step-down + dual-battery equaliser | 16-32 VDC (24V side) | 12 VDC / 100A or 30A SKU | Passive (finned aluminium, IP67 + IP66K) | 290 × 245 × 55.5 mm |
The EBX-2512 is the right choice for the 6 kW HV-DCDC role: secondary on a heavy-duty programme, primary on a mid-duty / light-duty programme. For the heavy-duty 36 kW main HV-DCDC controller role, look at EBX-2314; for the 30 kW DC-AC inverter (vehicle-to-load 220 VAC) role, look at EBX-2514; for the downstream 24V→12V step-down + dual-battery equaliser role, look at EBX-2407.
Manufacturing & testing
Built under IATF 16949 with APQP project planning and a PPAP package available for OEM programmes. Every unit is end-of-line functional-tested before packaging — the HV input voltage range across the 400-1100 VDC envelope (cold-start, mid-range, top-range) at the rated and the extended working points, the 24V output regulation under the full 6 kW continuous load, the DC 4480 V / 1 min (or AC 3200 V / 1 min) live-to-chassis withstand voltage check, the leakage-current measurement (≤ 5 mA), the insulation resistance check at 90 % RH (≥ 20 MΩ), the dual-fan operation (each fan independently driven and monitored), the CAN bus health on the 12-pin signal connector path, the 2-bit board ID-code read-back, the key-ON / VCU wake-up handshake and the IP68 main-housing ingress baseline are all checked.
How to ask
The EBX-2512 belongs to the Smart Control Modules family. To request the harness drawing, the HV-side rated voltage selection (600 V vs 900 V) per your traction-pack architecture, the CAN signal-ID assignment, the board ID-code mapping table or a PPAP package, please use the contact page with your target vehicle programme, traction-pack nominal voltage and working range, expected annual volume and key technical requirements (24V auxiliary peak load, mounting position, thermal-environment ambient, EMC profile, IP grade). Drawings welcome.
