izak / bms-bridge Goto Github PK

During a grid failure, the ESS mechanism in the CCGX/Multi will let the Multi continue inverting until one of these conditions apply:

1. the batteries shuts itself down in undercharge protection (a last resort, which requires a user reset)
2. dynamic cutoff lower limits, as setup in the ESS Assistant, are reached

Besides those, something extra is necessary: when /Info/MaxDischargeCurrent == 0 it should stop inverting. Aka go to charger only mode:

dbus -y com.victronenergy.vebus.ttyO1 /Mode SetValue %2

And once /Info/MaxDischargeCurrent != 0, set it back to full operation, which is Mode 3.

All possible modes are:

1=Charger Only;
2=Inverter Only;
3=On;
4=Off

Note that I think that the best way to do this is to use the charger only mode. If that is really the case is something we'll need to find out by testing.

In Venus v1.73 the naming of the Battery/BMS related D-Bus service was changed. See here:
https://git.victronenergy.com/can/lg_resu_interface/commit/e91f248689e9bd911a4d1e2a43ee9f5b8153ed6f

Some info from a v2.00 system (which is the same as v1.73 and v1.74 for this aspect of BMS D-Bus service naming):

root@ccgx:~# dbus -y
org.freedesktop.DBus
com.victronenergy.hub4
com.victronenergy.qwacs
com.victronenergy.system
com.victronenergy.logger
com.victronenergy.fronius
com.victronenergy.vebus.ttyO1
com.victronenergy.battery.socketcan_can0
com.victronenergy.settings
net.connman
fi.epitest.hostap.WPASupplicant
fi.w1.wpa_supplicant1

root@ccgx:~# dbus -y com.victronenergy.battery.socketcan_can0 / GetValue
value = {'Alarms/CellImbalance': 0,
 'Alarms/HighChargeCurrent': 0,
 'Alarms/HighChargeTemperature': 0,
 'Alarms/HighDischargeCurrent': 0,
 'Alarms/HighTemperature': 0,
 'Alarms/HighVoltage': 0,
 'Alarms/InternalFailure': 0,
 'Alarms/LowChargeTemperature': 0,
 'Alarms/LowTemperature': 0,
 'Alarms/LowVoltage': 0,
 'Connected': 1,
 'Dc/0/Current': 0.0,
 'Dc/0/Power': 0,
 'Dc/0/Temperature': 25.5,
 'Dc/0/Voltage': 49.069999694824219,
 'DeviceInstance': 512,
 'Info/BatteryLowVoltage': 0.0,
 'Info/MaxChargeCurrent': 110.0,
 'Info/MaxChargeVoltage': 58.099998474121094,
 'Info/MaxDischargeCurrent': 110.0,
 'Mgmt/Connection': 'CAN-bus',
 'ProductId': 45060,
 'ProductName': 'LG resu battery',
 'Redetect': 0,
 'Soc': 15,
 'Soh': 100}

bms-bridge doesn't properly work against Venus v2.00. The reason is that dbus-systemcalc is now also writing to /link/network mode. Which is a bit mask, so dbus-systemcalc & bms-bridge were undoing each-others changes. The result is that solarchargers show Error #67 again.

A fix is coming: Venus v2.01 has a new version of dbus-systemcalc that also takes care of writing the bms/max-charge-current to the solar-chargers.

victronenergy/dbus-systemcalc-py@af23489

So what needs to be done is removing the lines of code related to writing the max-charge-current. Which leaves only the code that sets a Multi to Charger-only when the max-discharge-current == 0.