C9 Series Automotive Relays – Compact Pre-Charge Contactors for EV and Hybrid Systems
BSB C9 Series offers compact pre-charge relays for high-voltage switching in electric and hybrid vehicles. Supporting up to 750VDC and 12VDC/24VDC coils, they ensure reliable performance in battery disconnect units and onboard charging systems.
BSB’s C9 Series offers compact automotive pre-charge relays designed for high-voltage switching applications in electric and hybrid vehicles. With options supporting up to 750VDC and both 12VDC and 24VDC coil voltages, the C9 relays deliver reliable performance in energy-sensitive systems like battery disconnect units and onboard charging systems.
- High Voltage Support
- Compact Design
- Multiple Mounting Options
- High Reliability
- Suitable for Hybrid and Electric Vehicles
- Precision Manufacturing
- Compliant with RoHS standards
- All series are certified by UL, CE, TÜV standards
What Is an Automotive Pre-Charge Relay?
Pre-charge relays, also known as pre-charge contactors, are essential components in modern EV and hybrid systems. Their main role is to safely connect high-voltage circuits by pre-charging the capacitors through a resistor before the main contactor closes. This protects the main relay contacts from damaging inrush currents.
The C9 Series automotive relay from BSB is built exactly for this purpose — delivering precise pre-charge timing, compact size, and high-voltage safety performance. Whether you call it an automotive electrical relay or automobilerelay, its function remains critical in high-voltage power management.
C8 series part number
| Product | Part Number | Amp Rating | Switching Voltage | Coil Voltage Rating | Main Contact Form | Auxiliary Contact / Form | Load Termination | Mounting Type | Coil Characteristic | Certificates |
|---|---|---|---|---|---|---|---|---|---|---|
 | BSBC9-20 | 20A | 750VDC | 12VDC, 24VDC | SPST-NO (1 Form A) | / | PCB, Plug-in | / | Single-coil | UL, CE |
| BSBC9-40 | 40A | 750VDC | 12VDC, 24VDC | SPST-NO (1 Form A) | / | PCB, Plug-in | / | Single-coil | UL, CE |
Why Choose BSB’s C9 Series Pre-Charge Contactors?
As one of China’s most scalable and specialized manufacturers of high-voltage DC contactors and relays, BSB delivers products trusted by EV makers and energy innovators worldwide. The C9 Series reflects our expertise in pre-charge design — combining advanced contact technology, dielectric strength, and cost-effective volume production.
Whether you’re looking for an automotive pre charge contactor or a reliable automotive relay for auxiliary switching, the C9 series is a proven solution for demanding automotive applications.
Technical Specifications of the C9 Contactors
| Parameter | Specification |
|---|---|
| Rated Operating Voltage | 450VDC; 750VDC (for pre-charge use only) |
| Rated Current | Max 40A |
| Coil Voltage | 12VDC / 24VDC |
| Mounting Options | PCB type / Plug-in type |
| Insulation & Dielectric Strength | Engineered for high-voltage endurance |
Applications of C9 Automotive Relays
BSB’s C9 relays are engineered for next-generation electric mobility. They are widely used in:
Battery Disconnect Units (BDU)
Electric Vehicle Pre-Charge Circuits
Hybrid and Fuel Cell Electric Vehicles (FCEV)
Onboard Chargers (OBC)
Auxiliary Relay Circuits
Electric Motorcycles and Electric Forklifts
These pre-charge relays are ideal for managing high-voltage DC circuits, especially when compact design and high reliability are critical.
Customization and Integration Support
Need a tailored automotive relay for your specific application? BSB offers full customization for the C9 Series — from coil parameters to terminal types. We support rapid design iterations and provide complete technical support to simplify integration into your system.