A battery monitor shows how much energy remains in an auxiliary battery and how quickly the system is using or replacing it. That matters in a touring 4WD running a fridge, lighting, an inverter or other auxiliary loads. A basic 12v battery gauge only reports voltage, which changes under load and does not provide a dependable state-of-charge reading on its own.
A shunt-based monitor measures current entering and leaving the battery. From that information, it can calculate state of charge, amp-hours used and estimated time remaining at the present load. Logged data also helps show whether the charging system is keeping pace with consumption.
This collection includes the Victron BMV-712 Smart and Simarine Pico components and packages. The right platform depends on whether the vehicle needs straightforward auxiliary battery monitoring or a broader display for multiple parts of the electrical system.
Need it fitted? Our Ferntree Gully and Pakenham workshops supply and install everything in this range. Not sure which option suits your vehicle? Call our friendly staff on
1300 633 762 before you order.
KEY CATEGORIES AND WHAT THEY ARE BUILT FOR
VICTRON BMV-712 SMART
The BMV-712 Smart is a Bluetooth-connected Victron battery monitor supplied with a shunt. It suits a single auxiliary battery system and owners who want data at the monitor head or through the app. It can also provide a secondary voltage reading for the starter battery, without measuring starter-battery current.
SIMARINE PICO SYSTEMS
The Simarine Pico platform combines a touchscreen display with compatible shunts and sensors. The active collection includes PICO-3 packages, the Pico+ display and a Simarine bundle containing PICO-3, SC303 and SCQ25T hardware. The platform can be expanded when a build needs information from multiple battery banks, tanks or temperature sensors.
BATTERY SHUNT OPTIONS
The SC303 battery shunt is rated at 300A in the product title and works with the Simarine Pico platform. A battery shunt must be selected for the system and installed so every relevant load and charging source is measured. A bypassed cable produces incomplete data, regardless of the display used.
WHY VOLTAGE ALONE IS NOT ENOUGH
Battery voltage changes when loads switch on, when a charger is operating and when the battery rests. Lithium batteries also have a relatively flat voltage curve through much of their usable capacity. These characteristics make voltage useful as a diagnostic reading, but unreliable as the only guide to remaining energy.
A shunt measures actual current flow instead. The monitor tracks what has entered and left the battery, then calculates the remaining state of charge from the configured capacity and synchronisation settings. This gives the driver information that can guide load management before the battery reaches the operating limits set for the system.
Accuracy still depends on correct installation and setup. The configured capacity must suit the battery, the monitor must synchronise at a confirmed full charge, and no load or charging cable can bypass the shunt.
CHOOSE BY USE CASE
SINGLE AUXILIARY BATTERY
For a daily-driven touring 4WD with one auxiliary battery, the BMV-712 Smart is the more direct option. It focuses on auxiliary battery current, state of charge and history. It also suits builds already using other Victron equipment, although each product still performs its own function.
MULTI-BANK OR CAMPER SYSTEM
A Simarine Pico system is better suited to a canopy camper, slide-on or other build that needs a central display and scope for additional measurements. Expansion requires compatible shunts or sensors for the items being monitored. Choose the display and modules around the actual banks, tanks and circuits in the vehicle rather than assuming one package covers every input.
BRANDS AND PRODUCTS IN THIS COLLECTION
The Victron battery monitor option is the BMV-712 Smart in grey. Simarine products include the Pico Essentials PICO-3 and SC303 package, Pico+ display, SC303 battery shunt and the listed PICO-3, SC303 and SCQ25T bundle. Check the individual product listing before ordering because a display, shunt and accessory module perform different roles and are not interchangeable.
WHAT A QUALITY INSTALLATION INVOLVES
The shunt sits in series with the auxiliary battery negative connection. Every monitored load and charging source must connect on the system side of that shunt. This can include the DC-DC charger, solar charger, inverter and auxiliary load circuits. If a negative path connects directly to the battery and bypasses the shunt, the readings will not include that current.
The BMV-712 Smart requires the shunt and monitor connections to be installed and configured correctly. A Simarine Pico installation also needs a suitable display location and data cabling between its components. Mounting, cable routing and access should be considered as part of the complete electrical system, particularly in canopies and camper bodies.
A battery monitor is a measurement device. It does not replace suitable circuit protection, a charger or a separate low-voltage disconnect where one is required by the build.
For local fitting, our Ferntree Gully and Pakenham workshops can install the shunt, route the monitored negative connections, mount the display where applicable, pair the app and calibrate the state-of-charge reading at a confirmed full battery. Send a service enquiry with the vehicle, battery system and major loads so we can assess the setup, quote the work and arrange a booking.
Submit a service enquiry with your vehicle details, or email sales@ultimateoffroad.com.au, and our friendly staff will confirm fitment, quote the work and arrange a booking at Ferntree Gully or Pakenham.
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