SOK Batteries and VictronConnect Settings

rmaddy

Full-time Solar-powered Trailer Life
Joined
Nov 16, 2019
Messages
1,210
Today I finally got far enough into my electrical setup on my cargo trailer camper conversion that I was able to start setting up some of my Victron components with my SOK batteries. But I am unclear on what some of the settings need to be while configuring the components using the VictronConnect app.

I think this thread can become the reference for setting up various Victron devices when connected to SOK batteries. Answer what you can and I'll keep it updated as people provide answers to my (many) questions below.

Feel free to share configuration files exported from VictronConnect.


What I have:

Two SOK 206Ah LiFePO4 batteries in series for a 24V nominal battery bank.
A Victron BMV-712 smart battery monitor
A Victron Smart Battery Protect 100
A Victron MultiPlus Compact 24V/2000W/50A Inverter/Charger (though I will only be using 30A shore power)
A Victron 150/45 Solar Charge Controller

I was given the following information by SOK for a 24V battery setup (just twice the values of 12V): Some of these numbers don't seem correct to me and few of them seem to correspond to values needed in VictronConnect.
  • Over Voltage Disconnect 29.4 V
  • Charging Limit Voltage 29.2 V
  • Over Voltage Reconnect 29.2 V
  • Equalize Charging Voltage shut off or 28.8 V
  • Boost Charging Voltage 29.2 V
  • Float Charging Voltage 29.2 V <-- Is this correct? I saw another reference that stated this as 27.2V
  • Boost Reconnect 26.6 V
  • Low Voltage Reconnect 20 <-- Why is this lower than the "Low Voltage Disconnect"?
  • Under Voltage Warning Reconnect Voltage 23 <-- Why is this the same as the "Under Voltage Warning"?
  • Under Voltage Warning 23
  • Low Voltage Disconnect 22
  • Discharging Limit Voltage 21
  • Equalize Duration 0
  • Boost Duration 12 hours <-- Is this correct? I saw another reference that stated this as 3 hours for 12V
The SK12V206 spec sheet has the following info for a single battery:

Charge Performance:​
  • Recommended Charge Current 40A
  • Maximum Charge Current 50A
  • Recommended Charge Voltage 14.6V <-- Is this the absorption or float charge voltage?
  • BMS Charge Cut-Off Voltage <14.6V
  • Reconnect Voltage >14.4V
  • Balancing Voltage <14.4V
Dischage Performance:​
  • Maximum Continuous Discharge Current 100A
  • Peak Discharge Current 200A (3s)
  • BMS Discharge Cut-Off Current 330A +/- 10A
  • Recommended Low Voltage Disconnect 11.2V
  • BMS Discharge Cut-Off Voltage >10.4V
  • Reconnect Voltage >11.6V


VictronConnect questions I have for each device:

BMV712 Battery Monitor:
Battery settings​
  • What should the "Charged voltage" be set to? It defaults to 26.4 for a 24V system.
  • What should the "Discharge floor" be set to? It defaults to 5%.
  • What should the "Tail current" be set to? It defaults to 4.00%.
  • What should the "Peukert exponent" be set to? Victron suggest 1.05 for Li-Ion.
  • What should the "Charge efficiency factor" be set to? Victron suggest 99% for Li-Ion.
Alarm settings - I have the shunt/monitor setup to monitor mid-voltage​
  • What should the "Mid-voltage alarm" be set to? It defaults to 2% deviation and clears on 1.5% deviation.


Smart Battery Protect:
Under Voltage settings​
  • What should the "Shut down" and "Restart" voltages be set to? I think the "Shut down" value should be SOK's "Recommended Low Voltage Disconnect" of 22.4V. Correct? Then is the "Reconnect Voltage" value of 23.2V correct for the "Restart"?


MultiPlus Compact
Inverter settings​
  • What should the "DC input low-shutdown" be set to? Would this be the same as the battery protect "Shut down" voltage?
  • What should the "DC input low restart" be set to? Would this be the same as the battery protect "Restart" voltage?
  • What should the "DC input low pre-alarm" be set to? Should this be SOK's "Under Voltage Warning" value of 23V?
  • Should the "Low SOC shut-down" setting be enabled? If so, what are good values for the Shut-down and Restart percentages?
Charger settings​
  • What should the "Charge current" be set to? SOK's recommend current of 40A? The max current of 50A? Somewhere in between?
  • What should the "Absorption voltage" be set to?
  • What should the "Float voltage" be set to?
  • What should the "Repeated absorption interval" be set to? Defaults to 7 days.
  • What should the "Repeated absorption time" be set to? Defaults to 1 hour.
  • What should the "Absorption time" be set to? Defaults to 8 hours.
  • What should the "Charge curve" be set to? Fixed? Adaptive? Or Adaptive+BatterySafe?
  • Should the "Stop after excessive bulk" option be enabled?
AC Input control settings​
  • Should conditional AC input connection be enabled? If so, what additional settings are best for SOK batteries?
What about VEConfigure? Is there anything specific in VEConfigure that isn't found in VictronConnect that needs to be setup?


Smart Solar Charge Controller
Battery settings​
  • Should the Absorption and Float voltages be set to the same values as those used under the Charger settings of the MultiPlus?
  • What should the "Low temperature cut-off" be set to? Defaults to 41ºF.
Load output settings
  • What should the "Operation mode" be set to? Defaults to "Battery Life".


Any help with these settings will be greatly appreciated. Again, I will summarize all answers to make it easy for future readers to locate this information.
 

rmaddy

Full-time Solar-powered Trailer Life
Joined
Nov 16, 2019
Messages
1,210
I found a SOK related question on the Victron community forum that has helped with some of this information.


As result of that thread and some other bits I've seen, here are my current VictronConnect settings for a Multiplus. These are for my 24/2000/50 inverter/charger but these should apply to most (all?) Multiplus. These are also for two 12V 206Ah batteries in series for 24V. Adjust as needed for your configuration.

MultiPlus Compact
Inverter settings​
  • DC input low-shutdown: 22.20V
  • DC input low restart: 23.20V
  • DC input low pre-alarm: 24.20V
  • Low SOC shut-down: Disabled
  • All other settings are not specific to the batteries and should be set as desired.
Charger settings​
  • Enable charger: enabled
  • Charge current: 70A (SOK recommends 40A but that is per battery so two in series could be 80A)
  • Absorption voltage: 28.80V
  • Float voltage: 27.20V
  • Repeated absorption interval: 7.00d
  • Repeated absorption time: 1.00h
  • Absorption time: 3h (this is still a big unknown)
  • Charge curve: Fixed
  • Lithium batteries: enabled
  • Use equalization: disabled
  • Stop after excessive bulk: enabled

Using those numbers leads to the following for the Smart Battery Protect.

Smart Battery Protect
  • Battery voltage: 24V
  • Under Voltage settings
    • Preset: User Defined
    • Shut down: 22.20V
    • Restart: 23.20V
  • Load disconnect & alarm settings - set as desired
I still have all of the original questions regarding setting up the BMV-712 and the Solar Charge Controller.

BMV712 Battery Monitor
Battery settings​
  • What should the "Charged voltage" be set to? It defaults to 26.4 for a 24V system.
  • What should the "Discharge floor" be set to? It defaults to 5%.
  • What should the "Tail current" be set to? It defaults to 4.00%.
  • What should the "Peukert exponent" be set to? Victron suggest 1.05 for Li-Ion.
  • What should the "Charge efficiency factor" be set to? Victron suggest 99% for Li-Ion.
Alarm settings - I have the shunt/monitor setup to monitor mid-voltage​
  • What should the "Mid-voltage alarm" be set to? It defaults to 2% deviation and clears on 1.5% deviation.
Smart Solar Charge Controller
Battery settings​
  • Should the Absorption and Float voltages be set to the same values as those used under the Charger settings of the MultiPlus?
  • What should the "Low temperature cut-off" be set to? Defaults to 41ºF.
Load output settings​
  • What should the "Operation mode" be set to? Defaults to "Battery Life".
Any feedback is appreciated.
 

QMDRoss

New Member
Joined
Apr 21, 2021
Messages
3
Location
Scotland
I found a SOK related question on the Victron community forum that has helped with some of this information.


As result of that thread and some other bits I've seen, here are my current VictronConnect settings for a Multiplus. These are for my 24/2000/50 inverter/charger but these should apply to most (all?) Multiplus. These are also for two 12V 206Ah batteries in series for 24V. Adjust as needed for your configuration.

MultiPlus Compact
Inverter settings​
  • DC input low-shutdown: 22.20V
  • DC input low restart: 23.20V
  • DC input low pre-alarm: 24.20V
  • Low SOC shut-down: Disabled
  • All other settings are not specific to the batteries and should be set as desired.
Charger settings​
  • Enable charger: enabled
  • Charge current: 70A (SOK recommends 40A but that is per battery so two in series could be 80A)
  • Absorption voltage: 28.80V
  • Float voltage: 27.20V
  • Repeated absorption interval: 7.00d
  • Repeated absorption time: 1.00h
  • Absorption time: 3h (this is still a big unknown)
  • Charge curve: Fixed
  • Lithium batteries: enabled
  • Use equalization: disabled
  • Stop after excessive bulk: enabled

Using those numbers leads to the following for the Smart Battery Protect.

Smart Battery Protect
  • Battery voltage: 24V
  • Under Voltage settings
    • Preset: User Defined
    • Shut down: 22.20V
    • Restart: 23.20V
  • Load disconnect & alarm settings - set as desired
I still have all of the original questions regarding setting up the BMV-712 and the Solar Charge Controller.

BMV712 Battery Monitor
Battery settings​
  • What should the "Charged voltage" be set to? It defaults to 26.4 for a 24V system.
  • What should the "Discharge floor" be set to? It defaults to 5%.
  • What should the "Tail current" be set to? It defaults to 4.00%.
  • What should the "Peukert exponent" be set to? Victron suggest 1.05 for Li-Ion.
  • What should the "Charge efficiency factor" be set to? Victron suggest 99% for Li-Ion.
Alarm settings - I have the shunt/monitor setup to monitor mid-voltage​
  • What should the "Mid-voltage alarm" be set to? It defaults to 2% deviation and clears on 1.5% deviation.
Smart Solar Charge Controller
Battery settings​
  • Should the Absorption and Float voltages be set to the same values as those used under the Charger settings of the MultiPlus?
  • What should the "Low temperature cut-off" be set to? Defaults to 41ºF.
Load output settings​
  • What should the "Operation mode" be set to? Defaults to "Battery Life".
Any feedback is appreciated.
Not sure I agree with your charging current calculations, two batteries in parallel would allow 80 amp charging, 40 A to each battery, with 2 in series should the limit be 40 amp?
 

rmaddy

Full-time Solar-powered Trailer Life
Joined
Nov 16, 2019
Messages
1,210
Not sure I agree with your charging current calculations, two batteries in parallel would allow 80 amp charging, 40 A to each battery, with 2 in series should the limit be 40 amp?
Good question. Since amps normally stay the same for things in series, it does seem like two batteries in series would have the same charge current limit as a single battery. So maybe I should set the charge current to the recommended 40A.
 

foxburrow

New Member
Joined
Oct 5, 2021
Messages
23
Were you ever able to determine the "Charged Voltage" with this setup? I am running a similar system. The max charge I have been able to get the batteries up to while running the generator is 26.8, so I am wondering if this is the "Charged Voltage" to input for the Victron BMV?
 

rmaddy

Full-time Solar-powered Trailer Life
Joined
Nov 16, 2019
Messages
1,210
Were you ever able to determine the "Charged Voltage" with this setup? I am running a similar system. The max charge I have been able to get the batteries up to while running the generator is 26.8, so I am wondering if this is the "Charged Voltage" to input for the Victron BMV?
I've been using 28.3V for the Charged Voltage for my 24V LiFePO4 setup. It's been working well for a few months now.
 
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