80-Amp Relay 12V Continuous Duty Solenoid Relay Battery

The MaySpare 80-Amp 12V continuous-duty solenoid is a heavy-duty battery isolator and relay designed to switch and protect dual-battery systems under high current loads.

This compact, rugged relay provides an easy way to add a secondary battery, isolate starting and auxiliary batteries, or route heavy loads without complex wiring. Built for continuous 12V operation with a high mechanical life, it handles regular duty cycles and short current surges while including the mounting hardware and insulated caps needed for straightforward installation.

How does this relay protect and manage two batteries?

The relay isolates two battery banks so one can run accessories while keeping the starter battery reserved. When energized it connects both batteries for charging; when de-energized it separates them to prevent unwanted discharge. It’s ideal for vehicles, marine craft, and solar or accessory systems that need reliable battery control.

• Continuous current rating: 80 A for sustained operation.
• Surge capacity: up to 150 A for short switching events.
• Copper contacts with silver-plated pins for improved conductivity and wear resistance.
• Normally-open design to keep batteries separated until the relay receives control voltage.

What are the electrical and mechanical specifications to know?

This solenoid runs on 12 VDC and is built for repeated operation with a long mechanical life. It supports momentary high-current switching and a continuous duty window suitable for most vehicle accessory loads, but requires attention to duty cycle in heavy-load scenarios.

• Rated voltage: 12 VDC.
• Continuous current: 80 A; maximum switching pulse: 150 A (brief).
• Max switching power: approximately 2000 W during short events.
• Designed for roughly 100,000 mechanical cycles of service.

How do I install it and what’s included in the kit?

The relay ships with mounting and terminal hardware so you can mount it securely and make clean power connections. Four large 100 A terminals handle the heavy load wiring and four smaller terminals tie into original power or control circuits; insulated red caps protect exposed posts.

• Includes 4 large 100 A terminals for load connections.
• Includes 4 small control terminals for original power wiring.
• Four insulated red terminal caps included for safety and corrosion protection.
• Mounting hardware and normally-open configuration; follow vehicle wiring best practices.

What operational limits or usage tips should I consider?

The relay should receive a steady control voltage to operate as intended; continuous heavy loading for hours at a time will raise temperature and may require cooling or rest periods. For extended duty or high-current runs, plan wiring gauge and fusing appropriately to protect the circuit.

• Requires stable control voltage for reliable switching.
• Continuous heavy use recommended in multi-hour increments with cooling breaks.
• Use correct wire gauge and fuse sizing to match 80 A continuous rating and surge capability.
• Compatible replacement for several OEM part numbers (reference compatibility list when replacing units).

Who is this for? Install the MaySpare 80A 12V continuous-duty solenoid if you’re adding a secondary battery to a truck, RV, boat, or off-grid setup and need a durable, straightforward isolator/relay that supports high currents and repeated cycles. It’s suited to mechanics, installers, DIYers, and fleet operators who want a compact, serviceable relay with included terminals and protective caps. If you’re planning prolonged high-load operation, pair it with proper wiring, fusing, and periodic cooling intervals for longest life.