A simple flow that creates a virtual battery and calculates the cell voltage difference in mV and percentage deviation, inserting it as the virtual battery voltage.
If you then create a widget for the virtual battery voltage you will have a nice chart showing the cell difference over time and a summary on the VRM dashboard (unfortunately I can’t change the unit in VRM).
It does use the global variables for cell min/mx so you need to drop a victron BMS node for each of those anywhere in node red.
[
{
"id": "e454b672adeedd27",
"type": "victron-virtual",
"z": "20fec985ee013124",
"name": "Cell Differnce mV",
"outputs": 1,
"device": "battery",
"default_values": false,
"acload_nrofphases": 1,
"enable_s2support": false,
"battery_capacity": "400",
"include_battery_temperature": false,
"battery_voltage_preset": "custom",
"battery_voltage_custom": "20",
"generator_type": "ac",
"generator_nrofphases": 1,
"include_engine_hours": false,
"include_starter_voltage": false,
"include_history_energy": false,
"grid_nrofphases": 1,
"include_motor_temp": false,
"include_controller_temp": false,
"include_coolant_temp": false,
"include_motor_rpm": true,
"include_motor_direction": true,
"position": 0,
"pvinverter_nrofphases": 1,
"switch_1_type": 1,
"switch_1_min": 0,
"switch_1_max": "",
"switch_1_initial": 0,
"switch_1_label": "",
"switch_1_unit": "",
"switch_1_step": 1,
"switch_1_customname": "",
"switch_1_group": "",
"switch_1_include_measurement": false,
"switch_1_rgb_color_wheel": false,
"switch_1_cct_wheel": false,
"switch_1_rgb_white_dimmer": false,
"fluid_type": 0,
"include_tank_battery": false,
"include_tank_temperature": false,
"tank_battery_voltage": 3.3,
"tank_capacity": 0.2,
"temperature_type": 2,
"include_humidity": false,
"include_pressure": false,
"include_temp_battery": false,
"temp_battery_voltage": 3.3,
"start_disconnected": false,
"x": 190,
"y": 980,
"wires": [
[]
]
},
{
"id": "b0f3ec50392a32ec",
"type": "victron-output-custom",
"z": "20fec985ee013124",
"service": "com.victronenergy.battery/100",
"path": "/Dc/0/Voltage",
"serviceObj": {
"service": "com.victronenergy.battery/100",
"name": "Debug battery (100)"
},
"pathObj": {
"path": "/Dc/0/Voltage",
"name": "/Dc/0/Voltage",
"type": "number",
"value": 48
},
"name": "Cell Delta",
"onlyChanges": false,
"roundValues": "no",
"rateLimit": 0,
"conditionalMode": false,
"condition1Operator": ">",
"condition2Enabled": false,
"condition2Service": "",
"condition2Path": "",
"condition2Operator": ">",
"logicOperator": "AND",
"outputTrue": "true",
"outputFalse": "false",
"outputOnChange": false,
"debounce": 2000,
"x": 580,
"y": 980,
"wires": []
},
{
"id": "fcf4b01f34f27893",
"type": "function",
"z": "20fec985ee013124",
"name": "Calc cell delta",
"func": "let max = global.get(\"victronenergy.battery._512.System.MaxCellVoltage\");\nlet min = global.get(\"victronenergy.battery._512.System.MinCellVoltage\");\nlet delta = Math.round((max - min)*100);\nflow.set(\"celldelta\",delta);\nmsg.payload = delta;\nreturn msg;",
"outputs": 1,
"timeout": 0,
"noerr": 0,
"initialize": "",
"finalize": "",
"libs": [],
"x": 420,
"y": 980,
"wires": [
[
"b0f3ec50392a32ec"
]
]
},
{
"id": "a8dad2026f4245b2",
"type": "inject",
"z": "20fec985ee013124",
"name": "trigger",
"props": [
{
"p": "payload"
}
],
"repeat": "5",
"crontab": "",
"once": true,
"onceDelay": 0.1,
"topic": "",
"payload": "",
"payloadType": "date",
"x": 340,
"y": 900,
"wires": [
[
"fcf4b01f34f27893",
"73b40d79d6d7ccac"
]
]
},
{
"id": "b7eede020a033404",
"type": "victron-output-custom",
"z": "20fec985ee013124",
"service": "com.victronenergy.battery/100",
"path": "/Soc",
"serviceObj": {
"service": "com.victronenergy.battery/100",
"name": "Debug battery (100)"
},
"pathObj": {
"path": "/Soc",
"name": "/Soc",
"type": "number",
"value": 80
},
"name": "SOC",
"onlyChanges": false,
"roundValues": "no",
"rateLimit": 0,
"conditionalMode": false,
"condition1Operator": ">",
"condition2Enabled": false,
"condition2Service": "",
"condition2Path": "",
"condition2Operator": ">",
"logicOperator": "AND",
"outputTrue": "true",
"outputFalse": "false",
"outputOnChange": false,
"debounce": 2000,
"x": 590,
"y": 1060,
"wires": []
},
{
"id": "73b40d79d6d7ccac",
"type": "function",
"z": "20fec985ee013124",
"name": "SOC",
"func": "let delta = flow.get(\"celldelta\");\nlet avgv = global.get(\"victronenergy.battery._512.Dc._0.Voltage\")/16*1000;\nmsg.payload = Number(((delta / avgv) * 100).toFixed(3));\nreturn msg;",
"outputs": 1,
"timeout": 0,
"noerr": 0,
"initialize": "",
"finalize": "",
"libs": [],
"x": 310,
"y": 1060,
"wires": [
[
"b7eede020a033404"
]
]
},
{
"id": "bc9b19d300371c34",
"type": "victron-input-battery",
"z": "20fec985ee013124",
"service": "com.victronenergy.battery/512",
"path": "/Dc/0/Voltage",
"serviceObj": {
"service": "com.victronenergy.battery/512",
"name": "Fleadung Wonk",
"communityTag": "battery"
},
"pathObj": {
"path": "/Dc/0/Voltage",
"type": "float",
"name": "Battery voltage (V)"
},
"name": "Battery Voltage",
"onlyChanges": false,
"roundValues": "no",
"rateLimit": 0,
"conditionalMode": false,
"outputTrue": "true",
"outputFalse": "false",
"debounce": "2000",
"x": 180,
"y": 1100,
"wires": [
[]
]
},
{
"id": "4fa151dc23989d7b",
"type": "global-config",
"env": [],
"modules": {
"@victronenergy/node-red-contrib-victron": "1.7.3"
}
}
]
