Hamolar 12V 200A Continuous-Duty SPST Relay 2-Pack — Heavy-Duty Split-Charge with Silver-Plated Contacts

Hamolar 2-pack 12V 200A continuous duty SPST relay is a heavy-duty make-or-break switching solution designed for split-charging and high-current automotive, marine, and truck electrical systems. Replacing or upgrading charging and accessory circuits often means moving bulky current away from delicate control switches — this Hamolar relay set lets you switch large loads reliably without complex wiring. Each relay is rated for continuous 200A duty, built with silver-plated internal contacts and alloy terminals for low resistance and long service life. The kit includes gaskets and terminal hardware to simplify installation and features flame-retardant housings for extra durability in mobile environments.

How does this relay help with split charging setups?

This relay provides a safe, high-current connection between two battery systems so the starter battery and auxiliary battery can be managed without manual jumper cables. Its SPST (single pole single throw) design gives a dependable on/off path when the source reaches operating voltage.

• 200A continuous switching capacity suitable for alternator-to-aux battery charging.
• Operates at 12VDC, handles up to 14V peak for automotive systems.
• Silver-plated contacts reduce voltage drop and wear under heavy loads.
• Included terminal gaskets and fasteners for cleaner, safer mounting.

What makes these relays suitable for truck, boat, and marine use?

Hamolar relays are constructed from flame-retardant materials and include alloy terminals that resist corrosion and heat. The robust internal design and strong external mounting options mean they withstand vibration and humidity common in trucks and boats.

• Silver-plated contacts for reduced oxidation and consistent conductivity.
• Flame-retardant housing for increased safety in confined engine spaces.
• Heavy-duty terminals that tolerate repeated installations and torque.
• Designed for continuous-duty operation under demanding marine or commercial conditions.

How do I install and wire this 4-terminal SPST relay?

Installation is straightforward: secure the relay to a solid mounting point, connect the power in and out on the main terminals, and wire the coil to a switched 12V source so the relay closes when charging or ignition is present. The kit supplies terminal hardware and gaskets to reduce installation errors and help protect connections.

• Mount relay on a grounded metal surface using supplied hardware for vibration resistance.
• Connect battery positive to the input terminal, auxiliary battery positive to the output terminal.
• Wire the coil to ignition or alternator sensing circuit (12–14V) for automatic operation.
• Use appropriately sized cable (rated for 200A) and fuse protection near the battery.

What performance and safety features should I expect?

Expect continuous 200A switching with low contact resistance, silver-plated contacts for long life, and a housing that resists heat and flame. The relays are built for repetitive make-and-break cycles and include parts to help achieve secure, weather-resistant connections.

• 200A continuous capacity for heavy alternator and accessory loads.
• Silver-plated internal contacts for stable performance and reduced arcing.
• Alloy terminals and supplied gaskets to improve mechanical and environmental sealing.
• Flame-retardant materials for improved heat resistance and safety.

Who is this for?

This Hamolar 2-pack is aimed at DIY mechanics, fleet technicians, and boat owners who need a rugged, simple relay for split charging, starter isolation, or powering high-current accessories. If you use dual-battery systems, add heavy winches, or run large inverters and want a reliable, install-ready relay that minimizes voltage drop and wiring complexity, this kit fits those needs without requiring specialized tools or custom housings.

FAQ

Q: Can these relays handle continuous alternator charging?

A: Yes — each relay is rated for 200A continuous duty and handles typical alternator charging at 12–14V when wired correctly.

Q: What wiring size should I use with a 200A relay?

A: Use heavy-gauge cable rated for 200A (typically 2/0 or 1/0 AWG) and protect the feed with a fuse or circuit breaker near the battery.