Victron battery monitors count every amp going into and out of your battery through a shunt on the negative cable. That gives you a real state of charge, amps, watts and time remaining, instead of a guess based on voltage. Voltage alone is especially misleading with LiFePO4, whose voltage barely changes across most of its capacity. Here’s how the lineup compares and which one fits your build.
Victron Battery Monitors Compared
| Model | Display | Relay | Sizes | Ports | Best for |
|---|---|---|---|---|---|
| SmartShunt | No (app only) | No | 300, 500, 1000, 2000A | Bluetooth, VE.Direct | Most vans, RVs and boats |
| SmartShunt IP65 | No (app only) | No | 500A | Bluetooth, VE.Direct | Wet or dusty locations |
| BMV-712 Smart | Yes, round or square bezel | Bi-stable, programmable | 500A shunt included, up to 10,000A with other shunts | Bluetooth, VE.Direct | Anyone who wants a wall display or alarm relay |
Sources: Victron SmartShunt, SmartShunt IP65 and BMV-712 Smart datasheets.
Both the SmartShunt and BMV-712 run from 6.5–70VDC, so one model covers 12V, 24V and 48V banks. Both draw under 1mA, and both have a second input for a starter battery voltage, a midpoint voltage or a temperature sensor.
SmartShunt or BMV-712?
The internals are close. You’re choosing between a phone app only (SmartShunt) and a phone app plus a wall display, audible alarm and relay (BMV-712). Victron says the BMV-712’s relay can turn off non-critical loads or start a generator. Its shunt connects to the display with the included 10m RJ12 cable.
What Size Shunt?
Size the shunt to your highest continuous current. A 12V system with a 3,000W inverter can pull about 250A (3,000 ÷ 12, estimate), so a 500A shunt fits with headroom. Bigger 12V inverter systems may need the 1000A model.
Do You Need a Separate Monitor at All?
Maybe not. A Lynx Smart BMS has a battery monitor built in, and some lithium batteries report state of charge over CAN to a Cerbo GX. A standalone shunt still helps if your battery has no communication port.
Key Settings
Victron’s SmartShunt manual says defaults suit most LiFePO4 batteries, apart from battery capacity, a Peukert exponent of 1.05, a charge efficiency factor of 99%, and a discharge floor of 10–20%. Match charged voltage and tail current to your charger, or the monitor will call the battery full too early.
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Buy: Victron SmartShunt 500A on Amazon or SmartShunt IP65 500A on Amazon
For the complete spec sheet and current manual, see the Victron BMV-712 Smart page.
Worked Example: Choosing a Monitor for Three Builds
Weekend van, 100Ah lithium, 1,000W inverter. Peak current is about 1,000 ÷ 12 ÷ 0.9 ≈ 93A (estimate), so the SmartShunt 300A covers it with plenty of headroom. App-only monitoring suits a small van where the phone is always nearby.
Sailboat, 400Ah house bank, chart table panel. A BMV-712 Smart puts a display at the chart table and its relay can sound an alarm or switch a load at a set state of charge. The second input can show the starter battery’s voltage.
Off-grid cabin, 48V bank, two 5kVA inverters. Combined peak draw could approach 200A (8,000W ÷ 48V ÷ 0.9 ≈ 185A, estimate), so a SmartShunt 500A fits. In a system with a Lynx distribution chain, a Lynx Shunt VE.Can is an alternative that combines the main fuse and monitor.
Worked Example: Reading the History
After a month, the SmartShunt’s history in VictronConnect might show something like this (illustrative):
| History item | Value | What it tells you |
|---|---|---|
| Deepest discharge | 62Ah | Your heaviest day used about 31% of a 200Ah bank |
| Average discharge | 35Ah | A typical day uses about 18% |
| Number of full cycles | 4 | How hard the bank is being cycled |
| Synchronisations | 28 | The battery reached full almost every day |
Those figures help you decide whether you have room to add loads, or whether more solar would help.
Using the Second Input
| Setting | What it shows | Typical use |
|---|---|---|
| Starter battery | Voltage of a second battery | Vans, RVs and boats with a separate engine battery |
| Midpoint | Balance between two halves of a series bank | 24V or 48V lead-acid banks |
| Temperature | Battery temperature, with the optional sensor | Temperature compensation and alarms |
Only one function can be used at a time, so choose the one that matters most for your system.
Installation in Brief
- Disconnect the battery negative and turn off all loads and chargers.
- Mount the shunt near the battery. Battery negative goes to the battery side.
- Move every other negative connection to the system side of the shunt.
- Connect the fused red wire to battery positive for power and voltage sensing.
- Set capacity, charged voltage and tail current in VictronConnect, then charge to full once to synchronise.
Sharing Data Over VE.Smart Networking
A SmartShunt or BMV-712 can share battery voltage, current and temperature with SmartSolar MPPTs, Orion XS chargers and Smart IP43 chargers over VE.Smart Networking. That gives the chargers a more accurate battery voltage reading and lets them use real battery current for the tail-current setting.
Getting Accurate Readings
Accurate state of charge depends on a few habits: every negative connection on the system side of the shunt, the correct battery capacity, and a full charge often enough for the monitor to synchronise. With those in place, the time-remaining and state-of-charge readings become a dependable guide for planning your day.
FAQ
Does the shunt go on positive or negative?
Negative. Battery minus on one side, everything else on the other side.
Can a SmartShunt talk to a Cerbo GX?
Yes, through VE.Direct.
Why does my monitor drift?
Usually because a load bypasses the shunt, or because charged voltage and tail current don’t match the charger.
Is the SmartShunt IP65 worth it?
It suits damp or dusty locations, such as an engine room, an open trailer box or a boat locker, where the standard SmartShunt would be exposed.
Can I add a display to a SmartShunt later?
Yes. A GX device with a GX Touch screen shows SmartShunt data, along with the rest of the system.
Sources: Victron SmartShunt, SmartShunt IP65 and BMV-712 Smart datasheets and SmartShunt manual (victronenergy.com, accessed Oct 2026); Mobile Solar Consulting, “Which Victron Shunt is BEST For You??”.
Related: LiTime 12V 50Ah LiFePO4 Battery Review, Klein CL390 Clamp Meter Solar Panel Test, XZNY 12V 18Ah LiFePO4 Battery Review, plus the Victron Energy Guide