Blue Sea Systems M2 DC Multimeter with SoC

The Blue Sea Systems M2 DC Multimeter with SoC goes beyond a simple voltage or current reading — it tracks the actual state of charge of a battery bank, so you know not just what the battery is doing right now but how much usable capacity remains.

Key features

• Measures 3 voltages and 1 current on a single bank
• Function range: 8-70V, up to 5000A (500A with the included shunt)
• Programmable shunt ratios for use with larger external shunts
• Alarms for high current, high/low voltage, and low battery
• Auto-dimming OLED display, 92dB audible alarm, isolated MOSFET relay for external circuit control

The included MOSFET relay is a genuinely useful feature beyond just monitoring — it can trigger an external circuit automatically based on any measured value, such as switching on a charge source or an alarm circuit when state of charge drops below a set threshold.

This meter suits anyone who wants real insight into battery health beyond a simple voltage snapshot — particularly useful on a boat with a house bank that sees regular deep cycling, where state of charge tells a much more complete story than voltage alone. Programmable shunt ratios also mean it can scale up to larger external shunts if the included 500A shunt isn't sized for your system's peak current.

Mount the display where it's easy to check at a glance from the helm or nav station, and route the shunt and sense wiring per the installation guide so readings stay accurate over the life of the installation.