Buyer's guide
Best Battery Monitors & Shunts for Off-Grid
Updated July 31, 2026 · Product availability last verified October 7, 2026
A battery monitor is your fuel gauge. With LiFePO4 it stops being optional, because the voltage stays nearly flat from full to almost empty, so you cannot read the charge level off a voltmeter. A shunt monitor counts every amp going in and out, which is the only way to know your real state of charge. Here are the ones worth installing.
Quick picks
Renogy 500A Battery Monitor with Shunt
Pairs with Renogy gear, has a built-in screen.
Check Price on AmazonWhich battery monitor for which situation
- Most off-grid builds: Victron SmartShunt 500A. It puts accurate coulomb counting and Bluetooth in the shunt, with your phone as the display.
- Panel-mounted display: Victron BMV-712 Smart. It adds a round wall screen to the same 500A shunt and VictronConnect app.
- Renogy system or wired-screen value: Renogy 500A Battery Monitor. Its backlit LCD and 10V to 120V range cover common 12V, 24V, and 48V banks.
- Large 48V bank: Victron SmartShunt 1000A. It adds current headroom for a large inverter while keeping the SmartShunt app and accuracy.
How the picks compare
| Model | Shunt rating | Display | Bluetooth / App | Best for |
|---|---|---|---|---|
| 500A | Phone only | Yes (VictronConnect) | Most builds | |
| 500A | Head unit | Yes (VictronConnect) | A wall display | |
| 500A | Backlit LCD | No (wired) | Renogy systems | |
| 1000A | Phone only | Yes (VictronConnect) | Large 48V banks | |
| 500A | Wired screen | No | Simple display |
Specs from the manufacturers' pages: Victron SmartShunt (500A/1000A) · Victron BMV-712 · Renogy 500A. Amazon availability re-checked October 7, 2026.
Victron SmartShunt 500A
Shunt: 500A / 50mVDisplay: Phone (no head)App: VictronConnect (Bluetooth)
Verdict: The Victron SmartShunt 500A is the best monitor for most off-grid builds: a 500A/50mV shunt with Bluetooth and VictronConnect, using your phone instead of a display head. You need the phone to read it and must enter the battery settings for accurate state of charge.
The SmartShunt is what most off-grid people end up installing. It is a shunt with Bluetooth built in and no display head, so your phone is the screen. It tracks state of charge, amp-hours used, current, voltage, and time remaining, and you program it for your bank in the VictronConnect app. If you do not need a panel-mounted screen, this is the one to buy.
What we like
- Accurate coulomb counting, the real fuel gauge for LiFePO4
- Reads everything in the VictronConnect app over Bluetooth
- Talks to other Victron gear over VE.Smart networking
Worth knowing
- No physical display, you need your phone to read it
- You have to enter your battery settings to get accurate SoC
Victron BMV-712 Smart
Shunt: 500A / 50mVDisplay: Round head unitApp: VictronConnect (Bluetooth)
Verdict: The Victron BMV-712 Smart is the best pick when you want a panel-mounted gauge: the same 500A/50mV shunt and Bluetooth app as the SmartShunt, plus a round display head. It costs more, and installation needs a panel cutout and data-wire run.
The BMV-712 is the SmartShunt with a round display head added. You get the same accurate state of charge, amp-hours, current, voltage, and time-to-go, but you can read it from a wall-mounted screen without pulling out your phone. It also has Bluetooth and an aux input that can watch a second battery, like a starter battery, or temperature.
What we like
- Wall-mounted display plus the same VictronConnect Bluetooth app
- Aux input monitors a second battery voltage or temperature
- Same trusted Victron accuracy and history tracking as the SmartShunt
Worth knowing
- Costs more than the SmartShunt for the added screen
- The display head needs a panel cutout and a data wire run
Renogy 500A Battery Monitor
Shunt: 500ADisplay: Backlit LCD headRange: 10V to 120V
Verdict: The Renogy 500A Battery Monitor is the value pick for Renogy systems and buyers who want a wired screen: a 500A shunt, backlit LCD, and 10V to 120V range. It has no Bluetooth, and its state-of-charge tracking is less refined than Victron's.
If you are already running Renogy panels and a Renogy charge controller, this is the easy match. It is a shunt with a backlit display head that shows voltage, current, consumed power, and remaining capacity, and it has programmable high and low voltage alarms. It does not have Bluetooth, so it is wired-only, but the screen is clear and the price is friendlier.
What we like
- Bright backlit display reads voltage, current, power, and capacity
- Programmable high and low voltage alarms
- Wide 10V to 120V range covers 12V, 24V, and 48V banks
Worth knowing
- No Bluetooth or app, you read it at the screen only
- SoC tracking is less refined than Victron's
Victron SmartShunt 1000A
Shunt: 1000A / 50mVDisplay: Phone (no head)App: VictronConnect (Bluetooth)
Verdict: The Victron SmartShunt 1000A is the right pick for a large 48V bank with a high-current inverter: a 1000A/50mV shunt with the same VictronConnect Bluetooth app and accuracy as the 500A model. It adds cost and is overkill for a small 12V van bank, and it still has no display head.
Same SmartShunt, bigger shunt. The 1000A version is what you want when a 48V cabin bank can pull serious current through a large inverter. It works exactly like the 500A model in the app, it just has the headroom so you never max out the shunt. Victron also makes a 2000A version for very large systems if you need even more.
What we like
- Handles the high current of a large 48V inverter
- Same VictronConnect app and accuracy as the smaller SmartShunt
- Steps up to a 2000A version for very large banks
Worth knowing
- Overkill and added cost for a small 12V van bank
- Still no display head, your phone is the screen
AILI TR16 500A Battery Monitor
Shunt: 500AVoltage: 8-120VDisplay: Wired
The TR16 is the 500A model, replacing the unverified 350A listing previously shown here. It measures current through an external shunt and displays battery state of charge. Set the correct capacity, synchronize it when the battery is full, and route every monitored load and charger through the shunt.
What we like
- Wired state-of-charge display
- 500A shunt for a correctly sized installation
Worth knowing
- No Bluetooth app
- Needs careful wiring and calibration
How to choose a battery monitor
Start with the shunt rating. The shunt has to handle the most current your system will ever push through it, which on a 12V van usually means a 500A shunt is plenty, while a large 48V cabin bank with a big inverter is happier with 1000A. A bigger shunt does not hurt accuracy, so when in doubt, size up rather than down.
Then decide if you want a screen or your phone. The Victron SmartShunt has no display and uses the VictronConnect app, which keeps the install clean. The BMV-712 and the Renogy add a physical screen you can glance at. If you want Bluetooth and the best state-of-charge tracking, the two Victron units are the pick. If you want a cheap screen and do not care about an app, the Renogy provides that option.
Last, make sure it actually counts coulombs. Every monitor here is a shunt-based coulomb counter, which is the whole point. Avoid cheap voltage-only gauges that just show battery volts, because on LiFePO4 that number tells you almost nothing about how full the bank really is. The reason why is in our LiFePO4 voltage chart.
Who should skip this: If your bank is still lead-acid and small, a basic voltmeter gets you most of the way, because lead-acid voltage actually tracks charge level. And if you run an all-in-one solar generator or power station, it already has a built-in fuel gauge, so you do not need a separate shunt. A standalone monitor pays off most on a LiFePO4 house bank you built yourself.
How to wire a campervan electrical system →
Frequently Asked Questions
Do I need a battery monitor for LiFePO4?
Yes, more than you do with lead-acid. LiFePO4 holds a nearly flat voltage across most of its charge, so a voltage reading cannot tell you whether you are at 80 percent or 30 percent. A shunt monitor counts every amp in and out, so it always knows the true state of charge. It is the only reliable fuel gauge for a lithium bank.
What is a shunt?
A shunt is a precise low-value resistor that all of your battery current passes through. The monitor measures the tiny voltage drop across it to know exactly how many amps are flowing in or out. By adding that up over time, it tracks how much energy you have used and how much is left. The shunt goes on the negative side of the battery.
SmartShunt vs BMV-712, which should I get?
They use the same 500A shunt and the same VictronConnect app over Bluetooth, so the readings are identical. The only real difference is the display. Buy the SmartShunt if you are happy reading the numbers on your phone, and buy the BMV-712 if you want a wall-mounted screen you can glance at without unlocking your phone.
Where do I install a shunt?
On the negative side of the battery, between the battery negative terminal and everything else. One small stud connects only to the battery negative, and the main stud connects to all your other negative wires and the chassis ground. Wiring it this way means every amp that enters or leaves the battery passes through the shunt, which is what makes the count accurate.
Can I monitor my battery over Bluetooth?
Yes, with the Victron SmartShunt or BMV-712. Both have Bluetooth built in and connect to the free VictronConnect app, so you can check state of charge, current, voltage, and history from your phone. The Renogy monitor has a wired display.
Does a battery monitor protect my battery like a BMS?
No, and that is an important distinction. A monitor only watches and reports, it does not disconnect anything. The protection job belongs to the battery's BMS, which cuts off charging or discharging in a fault. Think of the monitor as the fuel gauge and the BMS as the safety system. You want both.
How accurate is the state of charge reading?
Coulomb-counting monitors are very accurate as long as they are set up for your bank and the battery gets a full charge now and then to resync. Enter your true battery capacity during setup, and let the bank reach full charge regularly so the monitor can recalibrate to 100 percent. Skip that and the percentage slowly drifts.