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Jaco Reinecke avatar image
Jaco Reinecke asked

Cronjob's on VenusGX to up the SOC - anyone else seen this?

Hi,

This problem just does not seem to allow me to become "the boss" ... what am I missing or is this simply not possible?

The reason for this Cronjob is to slowly increase the SOC during the day, at specific times, based on data analyzed over a period, to prepare for the evening use i.e. SOC starts at a min of +-95%.

Note: If I set the SOC manually via ESS, it works perfectly. Never a hitch.

Equipment:

  • MPII 5kva grid-tied - latest firmware
    Smart 250/100 - latest firmware
    3.5kw panels
    150ah Lithium bank with a Daly BMS
    BMV712Smart - latest firmware
    VenusGX - latest release candidate

The CronJob:

# Set Inverter power

00 07 * * * root /usr/bin/dbus -y com.victronenergy.settings /Settings/CGwacs/MaxDischargePower SetValue 3800

# Push SOC Up - works perfectly, but alters the MPPT's production

40 08 * * * root /usr/bin/dbus -y com.victronenergy.settings /Settings/CGwacs/BatteryLife/MinimumSocLimit SetValue 70
30 11 * * * root /usr/bin/dbus -y com.victronenergy.settings /Settings/CGwacs/BatteryLife/MinimumSocLimit SetValue 80
30 14 * * * root /usr/bin/dbus -y com.victronenergy.settings /Settings/CGwacs/BatteryLife/MinimumSocLimit SetValue 95

# Set Inverter to use min batts during cooking times - works perfectly!

00 15 * * * root /usr/bin/dbus -y com.victronenergy.settings /Settings/CGwacs/MaxDischargePower SetValue 100

#Drop SOC for Evening use, set inverter to 500w - works perfect!

00 22 * * * root /usr/bin/dbus -y com.victronenergy.settings /Settings/CGwacs/BatteryLife/MinimumSocLimit SetValue 60

00 22 * * * root /usr/bin/dbus -y com.victronenergy.settings /Settings/CGwacs/MaxDischargePower SetValue 500


The Quirk/Problem/What am I missing part:

The moment the SOC gets increased by the Cronjob, the SOC being below the setting, the MPPT "misbehaves" for +-1 hour afterward by reducing its output.

In steps:
The panels are producing +-3kw at the time of the settings change
Grid-tied loads +-2kw, battery charging +-1kw
SOC is 88% at the time
Cronjob runs and sets SOC to 90%
MPPT drops output down to 1000w, charging only the batteries, ignoring the +-2kw potential power available, the grid supplying the +-2kw.

Manual intervention:
IF I see it, I drop the SOC manually to 85% in ESS, check that the panels pick up back to +-3kw, then manually set the SOC back to 90% under ESS - works perfectly if done manually.


So the question are:
Should this work?
If so, what am I missing?
Is there a conflict in the software, wrong SOC I'm adjusting?
Or is this simply not possible?


Looking forward to getting to the bottom of this quirk.

Regards
Jaco

Multiplus-IIVRMVenus OSVenus GX - VGX
2 |3000

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