Product Description

150A DC Current Shunt (50mV)

100A Continuous, 50mV output at full load.

If you want to measure DC current (amps) on your boat, you need a shunt.  This 150A / 50mV precision DC current shunt works with the DEX7 Marine Multimeter (and other 50mV-based marine amp meters) to accurately measure charge and discharge current from your battery bank.  Without a shunt, a meter can only measure voltage—not amps.

What Does a DC Shunt Do?

A shunt is a precision-calibrated resistor installed in line with your battery’s negative cable. As current flows through it, the shunt produces a very small, proportional signal (50mV at 150A). The DEX7 reads that signal and converts it into a real-time amp display.

• High current does not pass through the DEX7.
• All heavy current flows safely through the shunt.
• The meter reads only the small signal voltage.

Built for Accuracy and Marine Durability

This is a high-quality shunt made with real manganin resistance material for stable, repeatable readings. It also uses brass hardware for improved corrosion resistance in marine environments. The result is a shunt you can trust for accurate measurements over time—especially in the harsh conditions found on boats.

Continuous Duty Rating

While this shunt is rated for 150 amps maximum, it is designed for approximately 100 amps continuous duty (about 2/3 of its rated capacity). This makes it ideal for house battery monitoring, charging system monitoring, accessory loads, and most recreational boats.

If your boat regularly exceeds 100A continuous draw (large inverter systems, heavy DC loads), consider our 500A shunt option.

Why Monitor DC Current?

Most boats have zero current monitoring. Once you can see amps in real time, you can instantly understand what devices are drawing power, verify charging performance, and spot current spikes when pumps or other loads switch on. It’s one of the fastest ways to gain real confidence in your electrical system.

Technical Specifications

• Rated Current: 150A
• Output Signal: 50mV at 150A
• Approx. Continuous Duty: 100A
• Accuracy: 0.33%
• Calibrated: Yes
• Compatibility: DEX7 Multimeter and other 50mV amp meters
• Size: 2″ x 1.25″ x 1.7″ (tall)

Installation Notes

• Install in series with the current you want to measure (usually in negative, but can also be in positive).
• All monitored current must pass through the shunt.
• Connect DEX7 sense wires to the small signal screws (not the main lugs).
• Twist the sense wires to avoid small signal interference