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Programming Victron BMV-700, BMV-702, BMV-712 & SmartShunt for Lithium Batteries
This guide shows how to set up a Victron BMV-712 Smart, BMV-700, BMV-702, SmartShunt or SmartShunt IP65 battery monitor for a lithium (LiFePO4) battery bank, using the VictronConnect app or the buttons on a BMV head unit. All of these monitors leave the factory set up for lead-acid batteries, so a few settings must change before the state of charge (SoC) reading can be trusted.
Lithium settings depend on the battery manufacturer. The values below come from Victron's manuals, with a Victron Lithium Smart battery as the worked example. If your battery's manufacturer gives a different charge voltage or different monitor settings, use theirs.
Which Victron Battery Monitor Do You Have?
All of these models measure battery voltage and current through a shunt and use the same battery settings. Apart from the SmartShunt's charged voltage, the factory defaults are the same too. The differences are in how you connect to them and what the extra input and relay can do.
| Model | Display and buttons | VictronConnect via Bluetooth | Aux input (starter battery, midpoint or temperature) | Alarm relay and buzzer |
|---|---|---|---|---|
| BMV-700 | Yes | With the optional VE.Direct Bluetooth Smart dongle | No | Yes |
| BMV-702 | Yes | With the optional VE.Direct Bluetooth Smart dongle | Yes | Yes |
| BMV-712 Smart | Yes | Built in | Yes | Yes |
| SmartShunt (300A to 2000A) | No; set up in the app only | Built in | Yes | No; alarms show in the app or on a GX device, which can switch its own relay |
| SmartShunt IP65 (300A to 2000A) | No; set up in the app only | Built in | Yes | No; as for the SmartShunt |
The SmartShunt IP65 is the IP65-rated (dust- and water-resistant) version of the SmartShunt for exposed or damp locations. It connects, sets up and uses its aux input the same way, so everything below for the SmartShunt applies to it too.
Before You Start
- Every negative must go through the shunt. Only the battery negative connects to the battery side of the shunt (labelled BATTERY ONLY on the BMV shunt and BATTERY MINUS on the SmartShunt). Every load, inverter, battery charger, solar charger, DC-DC charger and the chassis connection, if used, connects to the other side (LOAD AND CHARGER, or SYSTEM MINUS). Anything wired straight to the battery negative is not counted, so the state of charge drifts. This is the most common fault we see.
- Update the firmware. VictronConnect tells you when newer firmware is available. Victron recommends updating on a new install.
- Have your battery details ready: the bank's capacity in Ah, your chargers' absorption and float voltages, and any monitor settings the battery manufacturer recommends.
- Watch for standby drain. The monitor draws a small current all the time. A lithium battery left fully discharged with even a tiny load on it can be permanently damaged, so isolate the battery when the system is stored. With a Victron Lithium Smart battery and BMS, Victron prefers powering the monitor from the BMS load-disconnect output so the BMS can switch it off.
Connecting with the VictronConnect App
- Install VictronConnect from the App Store or Google Play. It is also available for macOS and Windows; Windows connects only through the optional VE.Direct to USB interface.
- With the monitor powered, open the app and tap the monitor in the device list. A BMV-700 or BMV-702 needs the VE.Direct Bluetooth Smart dongle (or the USB interface) before it will appear.
- Enter the PIN when asked. The unique PIN is printed on the serial number sticker; if the sticker has no PIN, use the default 000000 (six zeros). Change the default PIN when the app prompts you.
- Tap the cog icon at the top right to open the settings, then open the Battery settings and enter the values from the worked example below.
- Optional: use the save-to-file icon in the settings menu to keep a copy of your settings for later or to share with your installer.
Worked Example: 12V 200Ah Lithium Bank with a SmartShunt
The example is a 12V bank of Victron Lithium Smart batteries totalling 200Ah (one 200Ah battery, or two 100Ah batteries in parallel), monitored by a SmartShunt 500A. The chargers use Victron's recommended lithium settings: 14.2V absorption with a 2-hour absorption time, then 13.5V float. The same values suit a BMV-712, BMV-700 or BMV-702.
| Setting (VictronConnect) | Factory default | Example value | Why |
|---|---|---|---|
| Battery capacity | 200Ah | 200Ah | The whole bank's capacity. Batteries in parallel add up (2 × 100Ah = 200Ah); batteries in series keep the capacity of one battery at the higher voltage. |
| Charged voltage | 13.2V on a 12V BMV (the SmartShunt manual lists 0V, so always set it) | 14.0V | Just below the 14.2V absorption voltage, so the monitor only resets to 100% at the end of a full charge. See Choosing the Charged Voltage below. |
| Discharge floor | 50% | 20% | Victron suggests 10–20% for lithium unless the battery supplier says otherwise. Time-to-go counts down to this level. It also sets the low SoC alarm default and, on a BMV, the low SoC relay. |
| Tail current | 4.00% | 4.00% (8A), or 3.00% (6A) | The battery counts as full once charge current falls below this. The 4% default suits most systems; 3% waits a little longer before calling the battery full. Don't set it lower than your chargers actually reach before they end absorption. |
| Charged detection time | 3 minutes | 3 minutes | How long the voltage and tail current conditions must both hold before the monitor resets to 100%. |
| Peukert exponent | 1.25 | 1.05 | Lithium loses very little capacity at high discharge rates. Victron's value for lithium unless the battery supplier advises otherwise. |
| Charge efficiency factor | 95% | 99% | Lithium stores almost all of the charge it receives. Victron recommends 99%. |
| Current threshold | 0.10A | 0.10A | Currents smaller than this are treated as zero, so small offsets do not slowly drag the SoC down. |
| Time-to-go averaging period | 3 minutes | 3 minutes | Range 0–12 minutes. A longer period gives a steadier time-to-go reading. |
Choosing the Charged Voltage
Charged voltage needs the most thought on a lithium system. The monitor resets itself to 100% (synchronises) only when three things happen together: the voltage is above the charged voltage, the charge current is below the tail current, and both have held for the charged detection time. In the 200Ah example that means above 14.0V, below 8A, for 3 minutes.
Set 14.0V on a 12V bank (28.0V on 24V, 56.0V on 48V). While it charges, a lithium battery's voltage stays above 13.3V for much of the charge, and higher still when it is charged cold or at a high current. A lower setting such as 13.2–13.3V is therefore met long before the battery is full, and the first time the charge current dips below the tail current (a passing cloud, or a charger stepping back) the monitor resets to 100% too early. The voltage only passes 14.0V at the end of the charge, just below the 14.2V absorption voltage, so the monitor resets at the right point every time. Victron's own fix for early synchronisation in solar systems is the same: set the charged voltage slightly below the absorption voltage.
14.0V only works if at least one charger (solar, DC-DC or mains) regularly reaches its absorption voltage, 14.2V in this example, and holds it long enough for the current to fall below the tail current. If none of your chargers goes above 14.0V, the monitor never synchronises and the reading drifts. In that case use Victron's general rule instead: 0.2–0.3V below the float voltage, which is 13.2–13.3V with the 13.5V float recommended for Victron Lithium Smart batteries.
For Lithium Smart batteries, Victron also asks that the charger completes absorption and reaches float at least once a month. This gives the cells time to balance and lets the monitor synchronise.
24V and 48V Systems
Percentage settings stay the same at any system voltage. Voltage settings scale by two for 24V and by four for 48V. Capacity is the bank's Ah at its own voltage, so four 12V 200Ah batteries in series make a 48V 200Ah bank. Victron Lithium Smart batteries come in 12.8V and 25.6V models; 48V banks are built from batteries in series.
| Setting | 12V 200Ah | 24V 200Ah | 48V 200Ah |
|---|---|---|---|
| Charger absorption / float (Victron Lithium Smart) | 14.2V / 13.5V | 28.4V / 27.0V | 56.8V / 54.0V |
| Charged voltage | 14.0V | 28.0V | 56.0V |
| Charged voltage if no charger goes above it (float rule) | 13.2–13.3V | 26.4–26.6V | 52.8–53.2V |
| Tail current | 4.00% (8A), or 3.00% (6A) | 4.00% (8A), or 3.00% (6A) | 4.00% (8A), or 3.00% (6A) |
| Discharge floor | 20% | 20% | 20% |
| Peukert exponent / charge efficiency factor | 1.05 / 99% | 1.05 / 99% | 1.05 / 99% |
When its setup wizard finishes, a BMV detects the nominal voltage automatically: below 18V it assumes 12V, 18–36V it assumes 24V, and above 36V it assumes 48V. It cannot detect a 32V bank, so set the charged voltage by hand in that case. Check the charged voltage after any reset.
Programming a BMV with the Buttons
A BMV can also be set up without a phone. Hold SETUP for two seconds to open the settings menu, use + and − to find the setting number, and press SELECT to open it. Change the value with SELECT and the + and − buttons; a short beep confirms it. Press SETUP to go back to the menu, and press it again to return to normal mode.
| Setting number | Name | 12V 200Ah lithium example |
|---|---|---|
| 01 | Battery capacity | 200Ah |
| 02 | Charged voltage | 14.0V (13.2–13.3V if no charger goes above 14.0V) |
| 03 | Tail current | 4.00% (or 3.00%) |
| 04 | Charged detection time | 3 minutes |
| 05 | Peukert exponent | 1.05 |
| 06 | Charge efficiency factor | 99% |
| 07 | Current threshold | 0.10A |
| 08 | Time-to-go averaging period | 3 minutes |
| 16 / 17 | Low SoC relay: set / clear (16 is the discharge floor) | 20% / 90% |
| 69 | Aux input (BMV-702 and BMV-712 only) | None, starter battery, midpoint or temperature |
Aux Input: Starter Battery, Midpoint or Temperature
The BMV-702, BMV-712 Smart, SmartShunt and SmartShunt IP65 have one auxiliary input, set under Settings > Misc > Aux input in VictronConnect. It can do one of three jobs:
- Starter battery: shows the voltage of a second battery. Its negative must connect to the load side of the shunt.
- Midpoint: compares the two halves of a 24V or 48V bank made of batteries in series, and can raise an alarm if they drift apart (default threshold 2%; alarms are off until you enable them).
- Temperature: needs the separate Victron temperature sensor for the BMV-712 Smart and BMV-702, which also suits the SmartShunt. It is a different sensor from those supplied with Victron inverter/chargers and some battery chargers. With a sensor fitted, the temperature coefficient setting reduces the counted capacity below 20°C. Victron gives 0.5%cap/°C as typical for LiFePO4; the default of 0 turns this off.
The monitor does not set charge voltages, so there is no temperature compensation to turn off in its settings. If it shares battery temperature with Victron chargers over VE.Smart networking, set their temperature compensation to 0mV/°C (off), as Victron advises for its lithium batteries.
Synchronising and Checking the Reading
After setting up, charge the battery fully and check that the monitor resets to 100% by itself. To synchronise by hand when you know the battery is full, press Synchronise in the VictronConnect battery settings, or hold + and − together for three seconds on a BMV.
| What you see | Likely cause | What to check or change |
|---|---|---|
| Shows 100% before the battery is full | Charged voltage too low, often 13.2–13.3V on solar or when charging cold or at a high current | Set the charged voltage to 14.0V, just below absorption; increase the charged detection time and/or lower the tail current to 3% |
| Never reaches 100% | Battery not fully charged, charged voltage too high or tail current too low | Charge fully; lower the charged voltage and/or raise the tail current |
| SoC drifts over days or weeks | A negative wired straight to the battery, wrong capacity or no regular full charge | Move every negative to the load side of the shunt; check the capacity; charge fully regularly |
| SoC rises too fast or too slowly while charging | Battery capacity set wrong | Set the bank's total Ah |
| Always shows 100% | Shunt wired the wrong way round | Swap the battery and load connections on the shunt, or (firmware v4.19 or later) change the Current measurement direction setting |
Only use the zero current calibration if the monitor shows current when you are certain none is flowing. The only way to be certain is to remove every cable from the load side of the shunt first.
Victron Battery Monitors
Browse the Victron battery monitor range, including the BMV-712 Smart with its display and relay, the SmartShunt 500A, the SmartShunt IP65 500A for exposed or damp locations, and the temperature sensor for the aux input.
