WM686 12V 100A Split Charge Winch Relay – 4 Pin DC Relay

WM686 12V 100 Amp Heavy Duty Split Charge / Winch Relay

Meet the WM686 12V 100A Split Charge Relay — a robust, general-purpose voltage relay engineered for demanding electrical switching duties in cars, vans, marine boats, lawn mowers, winches, and more. Rated for a full 100 amps of continuous DC current, this 4-pin normally-open relay handles both long-duration and intermittent high-load switching with ease, making it an excellent choice for dual-battery split-charge systems, winch control circuits, and starter applications.

Made in Mainland China.

Key Features

• High Current Capacity: Rated at 100A — handles heavy electrical loads in automotive, marine, and outdoor power equipment applications.
• 12V DC Operation: Compatible with standard 12-volt DC electrical systems across cars, vans, boats, and mowers.
• 4-Pin Normally Open Design: Simple wiring with four terminal connections; circuit opens at rest and closes when the coil is energised.
• Dual-Mode Coil Power: 2.4W for long-duration continuous operation; 4.8W for intermittent/peak switching — optimised for efficiency and durability.
• Voltage Relay Theory: Activates reliably based on voltage signal, ideal for split-charge and winch relay circuits.
• Compact & Sturdy Build: Dimensions of 70 × 45 × 45 mm (approx. 2.76 × 1.77 × 1.77 in) and weighing just 76 g — easy to mount in tight engine bays or electrical panels.
• Wide Application: Suitable for cars, vans, trucks, marine/boat systems, lawn mowers, ATVs, and other DC-powered vehicles or equipment.

Technical Specifications

What's in the Box?

• 1 × WM686 12V 100A Split Charge / Winch Relay

Important Notes

• Slight dimensional deviations may occur due to manual measurement methods and tools.
• Product colour in images may vary slightly due to lighting, camera angle, and monitor settings.

Safety & Installation Resources

For guidance on safe electrical wiring practices for automotive and marine applications, refer to the U.S. Consumer Product Safety Commission (CPSC) and OSHA's Electrical Safety guidelines. Always follow safe wiring practices and consult a qualified electrician or auto technician if you are unsure about your installation.

Frequently Asked Questions

Q: What vehicles and equipment is the WM686 12V 100A relay compatible with?

A: The WM686 relay is designed for any 12V DC electrical system. It is widely used in cars, vans, trucks, marine boats, lawn mowers, ATVs, winch setups, and dual-battery split-charge systems. If your application runs on 12V DC and requires high-current switching up to 100A, this relay is a strong fit.

Q: What is the difference between the 2.4W and 4.8W coil power ratings?

A: The 2.4W rating applies to long-duration, continuous operation where the relay coil is energised for extended periods. The 4.8W rating is for intermittent or short-burst use, such as winch operation, where the relay is switched on and off repeatedly. Both modes are built into the WM686's design for versatility across different applications.

Q: How do I wire the WM686 4-pin relay?

A: The WM686 features a standard 4-pin normally-open configuration. Two pins connect to the low-current control circuit (coil), and the other two pins handle the high-current load (the main circuit). When voltage is applied to the coil pins, the relay closes and allows current to flow through the load pins. Always ensure your wiring gauge matches the 100A rating and use appropriate fusing for safety.

Q: Is this relay suitable for a split-charge dual-battery system?

A: Yes. The WM686 is an excellent choice for split-charge systems. When your vehicle's alternator raises the voltage above a set threshold, the relay closes to connect the secondary (leisure or auxiliary) battery to the charging circuit, then opens again when voltage drops — keeping your starter battery isolated from the auxiliary load.