Newmar 2-3-120A Isolator 2AIT 3BATT 120AMP

Why Reliable Battery Isolation Matters for Your Setup

Imagine heading out on a long road trip or anchoring in a remote bay, only to find your starting battery drained because your house batteries pulled power overnight. That's the frustration this heavy-duty isolator eliminates. Designed for demanding environments like RVs, marine vessels, trucks, and off-grid systems, it smartly manages charging from one or two alternators across up to three batteries. Each bank gets just what it needs—no overcharging, no cross-dumping—keeping your electronics humming and your engine ready to crank.

Built to handle the rigors of continuous use in harsh conditions, this isolator stands out with its robust diode technology that prioritizes safety and efficiency. Whether you're powering inverters, trolling motors, or cabin lights, it ensures seamless operation without the guesswork.

Seamless Charging Without the Hassle

This isolator works by blocking reverse current flow while allowing forward charging current to pass from your alternator(s) to multiple battery banks. Connect one or two alternator inputs to charge up to three outputs independently. It's perfect for setups with a primary cranking battery, house bank, and auxiliary like a bow thruster or winch battery.

In real-world use, users report it handles high loads effortlessly during extended drives or generator runs, maintaining voltage stability even as batteries reach full charge. The conservative diode ratings mean it runs cooler and lasts longer than budget alternatives that overheat under load.

Standout Features for Long-Term Durability

• Extreme Temperature Resilience: Thrives from -40°C to +80°C, ideal for desert hauls or arctic adventures.
• Corrosion-Resistant Build: Anodized aluminum housing shrugs off salt air and road spray.
• Secure Installation: Includes stainless steel hardware and terminal covers to prevent shorts and vibrations.
• Universal Compatibility: Suited for 12-48V negative ground systems, from 24V commercial trucks to 48V solar hybrids.
• Low Maintenance Design: No moving parts, no solenoids to fail—just plug-and-play reliability.

Performance You Can Trust Under Load

Engineered for full-time duty, it delivers continuous output up to 50°C, derating smoothly to 70% at 80°C for safety. Expect minimal heat buildup—just 5°C rise at max current when mounted vertically for airflow. Voltage drop stays low at 0.7V (50% load) to 0.9V full, preserving alternator efficiency and battery health.

Pro tip: Pair it with temperature-sensing alternator regulators for optimal charging curves, extending battery life by preventing sulfation or gassing.

Real-World Applications and Pro Tips

RV enthusiasts use it to separate chassis and coach batteries, ensuring you never strand yourself chasing campground outlets. Boaters love it for dual-bank charging without killing the starter. Heavy equipment operators rely on it for work truck fleets where downtime costs big.

For best results, mount in a well-ventilated spot away from exhaust heat. Regularly inspect terminals for tightness and clean corrosion—simple habits that keep it performing like new. Avoid setups with self-exciting alternators; opt for externally regulated ones to match perfectly.

Frequently Asked Questions