The short answer. Out of the box, a SmartShunt is set up for lead-acid. For lithium, Victron says to change five things. Set charged voltage to 13.9 V on a 12 V bank, Peukert to 1.01, charge efficiency to 98% and the discharge floor to 10-20%. Then set the tail current above the point where your charger stops. Enter your real capacity first.
You’ll need
- A Victron SmartShunt 500A, Victron SmartShunt IP65 500A or Victron BMV-712 Smart, already fitted on the battery negative (Boat lithium battery wiring diagram: 2 simple setups shows where)
- The VictronConnect app on your phone, up to date
- Your lithium battery’s spec sheet: rated capacity, plus any monitor settings the maker gives
- Your charger’s absorption voltage and the current where it stops charging
That’s the kit. Victron’s manual says most settings can stay at their factory defaults, so you’re only changing a handful. Here’s the order.
Why does a SmartShunt need different settings for lithium?
Victron’s manual says the defaults are built for lead-acid batteries like AGM and gel. Lithium behaves differently. It copes far better with heavy loads, wastes less energy charging, and can go much deeper. Leave the lead-acid numbers in and the state of charge and time-remaining figures come out wrong.
The monitor resets to 100% (Victron calls it synchronising) when three things are true together: the voltage is above the charged voltage, the current is below the tail current, and both have held for the charged detection time. Those three settings do most of the work.
The settings, step by step in VictronConnect
Open the app, tap your SmartShunt, then the cog at the top right. Most of these live under Settings > Battery.
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Change the PIN and update the firmware. If there’s no PIN on the sticker, the default is 000000. Victron strongly advises changing it. Then check Product info for a firmware update.
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Battery capacity. The default is 200 Ah. Enter your bank’s rated amp-hours from the battery maker. With firmware v4.19 or later the range goes up to 32,500 Ah. Older firmware stops at 9,999 Ah.
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Charged voltage. Victron’s lithium values: 13.9 V for 12 V, 27.8 V for 24 V, 41.7 V for 36 V, 55.6 V for 48 V. The rule behind it is to set it just below the voltage where your charger finishes, usually its absorption voltage.
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Tail current. The default is 4% of capacity (on a 200 Ah bank that’s 8 A). Victron doesn’t give a separate lithium number. It does say that some lithium chargers stop charging when current falls below a set point. In that case, set the tail current higher than that point. If your battery maker gives a tail current, use theirs.
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Charged detection time. The default is 3 minutes, with a range of 0 to 100. It’s there so a quick voltage spike doesn’t fake a full charge. Victron gives no lithium-specific value, so leave it at 3 unless your battery maker says otherwise.
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Peukert exponent. Set 1.01, unless your battery maker gives a different figure. The default 1.25 is a lead-acid number. Victron notes that 1.00 turns Peukert compensation off.
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Charge efficiency factor. Set 98% (the default is 95%). Victron says lithium charges much more efficiently than lead-acid.
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Discharge floor. Victron suggests 10-20% for lithium, unless your battery maker advises otherwise. The default is 50%. This sets the “time remaining” target and the default for the state of charge alarm, so it’s worth getting right.
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Alarms. These are off by default. Slide each one on in the app. Victron gives no lithium alarm voltages, so take the high and low limits from your battery maker. Our advice: set the low voltage and low state of charge alarms to go off before the BMS would cut the battery out, not at the same point. An alarm triggers once the value has been past its set point for more than 10 seconds.
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Aux input (optional). Under Settings > Misc > Aux input, choose starter battery, midpoint or temperature, or none. You get one.
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First sync. Charge the bank full. Or, if you know it’s full, press Synchronise in the battery settings. Until it syncs, the state of charge shows three dashes.
Quick reference: Victron’s defaults vs Victron’s lithium values
| Setting | Default | For lithium (per Victron) |
|---|---|---|
| Battery capacity | 200 Ah | Your bank’s rated Ah |
| Charged voltage (12 V) | 14.0 V | 13.9 V |
| Tail current | 4.00% | Above your charger’s stop current; otherwise your battery maker’s value |
| Charged detection time | 3 minutes | No lithium value given; battery maker’s value if they have one |
| Peukert exponent | 1.25 | 1.01, unless the battery maker says otherwise |
| Charge efficiency factor | 95% | 98% |
| Discharge floor | 50% | 10-20%, unless the battery maker says otherwise |
| Alarms | Off | Your battery maker’s limits |
From Victron’s SmartShunt manual. The SmartShunt IP65 and BMV-712 manuals carry the same values.
What about the BMV-712?
Same settings, same values. You can set it in VictronConnect over Bluetooth, or on the display’s setup menu. On the display, it’s setting 01 for capacity, 02 for charged voltage, 03 for tail current, 05 for Peukert, 06 for charge efficiency and 16 for the discharge floor. The one real difference is alarms. A BMV-712 beeps, flashes its backlight and can switch its relay. A SmartShunt shows alarms only in the app or on a GX device. Victron’s fix for that is to use the relay on a GX device. Weighing the two? See SmartShunt vs BMV-712 vs BMV-700.
My state of charge is wrong. What do I check?
It jumps to 100% too early. Charged voltage is probably set too low. Victron’s example is solar at the end of the day. The voltage sits above the setting while the current fades with the sun, so the monitor calls it full when it isn’t. Raise the charged voltage toward your charger’s absorption voltage.
It never reaches 100% and drifts. Charged voltage is set too high, so the battery never gets there. Or the tail current is below the point where your charger stops. Lower the first or raise the second. Then give the bank a full charge.
It shows three dashes. The monitor lost power or was just fitted. Charge it full or press Synchronise.
Can a monitor flatten a lithium battery?
Yes, if it’s left long enough. Victron’s warning is plain. After a low-voltage shutdown, a lithium battery can be down to 1%, and any further draw can damage it for good. Their example: a 1 mA draw can damage a 100 Ah battery left discharged for more than 40 days. The monitor itself is a small load, along with alarms, standby gear and charger back-drain.
Victron’s advice is to isolate the battery when the boat is left. Open the battery switch, pull the fuse or take off the positive. Do it every time you leave the boat for a while.
Does this guide fit your setup?
This applies if: – You have a Victron SmartShunt (standard or IP65) or BMV-712 on a LiFePO4 bank. – Your bank is 12, 24, 36 or 48 V. – You set it up through VictronConnect or the BMV display.
This doesn’t apply if: – Your lithium battery’s own BMS reports state of charge to your system and the maker says not to add a monitor. Follow the battery manual. – You run a different lithium chemistry than LiFePO4. Use the battery maker’s numbers for everything. – You’re still on lead-acid. Leave the lead-acid defaults and enter your capacity (Victron recommends the 20-hour rating).
Products used in this guide
| Product | Why it’s here |
|---|---|
| Victron SmartShunt 500A | Set up entirely from your phone. For a dry battery space. |
| Victron SmartShunt IP65 500A | Same settings, in a sealed IP65 case for damp spots. |
| Victron BMV-712 Smart | Same settings, plus a display, buzzer and relay. |
Prices show live from the store. All three are in Battery monitors. Once the settings are in, the Run time calculator shows how long your bank lasts on your loads.
Bundles for this job: Shore charger + battery monitor bundle, RV battery monitor kit
Quick answers
What Peukert exponent should I use for LiFePO4 on a SmartShunt? 1.01, unless your battery maker gives another number. Victron’s default of 1.25 is for lead-acid. A setting of 1.00 switches Peukert compensation off.
What tail current should I set for lithium? Victron’s default is 4% of capacity and it gives no lithium figure. Set it higher than the current at which your charger stops charging, or use your battery maker’s value.
What charged voltage for a 12 V lithium battery on a SmartShunt? Victron recommends 13.9 V. It should sit just below the voltage where your charger finishes, usually the absorption voltage.
Does the SmartShunt beep when the battery is low? No. It has no buzzer or relay. Alarms show in VictronConnect or on a GX device. A BMV-712 has a buzzer and relay.
Why does my SmartShunt say 100% when the battery isn’t full? Usually the charged voltage is set too low, so the monitor syncs early, often on solar late in the day. Raise it toward your charger’s absorption voltage.
Sources
- Victron SmartShunt manual: https://www.victronenergy.com/upload/documents/SmartShunt/9172-Manual_BMV_and_SmartShunt-pdf-en.pdf
- Victron SmartShunt IP65 manual: https://www.victronenergy.com/upload/documents/SmartShunt_IP65/9172-Manual_BMV_and_SmartShunt-pdf-en.pdf
- Victron BMV-712 Smart manual: https://www.victronenergy.com/upload/documents/BMV-712_Smart/9172-Manual_BMV_and_SmartShunt-pdf-en.pdf
