Please bare with me, this is my first post here and I am new to Venus OS.
I have a RPi 4 running Venus OS 3.72, connected to two MPPTs 150/60, One Multiplus 12/3000 two Lifepo Kilovault batteries (bluetooth).
This system is on a boat in the remote areas, so lately I started shutting down the inverter at night to save power as the days are cloudy in this part of the world. But, yesterday, before turning off the Multiplex inverter, I decided to do a proper shutdown to the RPi. I am a former Unix/Linux sysadmin, so I just ssh and run a shutdown -h command. The RPi shutdown and powered off and so did the Multiplex inverter. Which turned off my wifi and starlink. But my surprise was that I was unable to use the app Victron Connect on my smartphone to connect to any of the devices. They were all in a state “Externel control…” . Same for the batteries that have their own app.
Is there a way to configure Venus OS in such a way that when it’s shutdown or crashed, it would give back control to every device ?
Thank you.
Those are two unrelated things. External control means that the charge is controlled by VenusOS (or rather DVCC) not the chargers own internal algorithm. Whether or not a charger is externally controlled has no impact on the ability to connect to it over bluetooth.
Since your devices show external control i guess DVCC is enabled. This then also means that VenusOS needs to run in order for the connected chargers to work. The MPPTs should start to show BMS lost error due to this.
As for the batteries i dont know. I assume you are reading battery information into VenusOS through Canbus. Since over bluetooth is not officially supported, at least afaik.
Thanks a lot for your reply.
I read the batteries through a third party device dbus-serialbattery with BatteryAggregator two aggregate my two parallel batteries.
Yes you are right for the MPPT complaining the BMS lost. However, I have lithium battery configuration specific to my batteries in those two MPPTs. What’s going to happen to that if the charging is now handed over to Venus OS ?
Also, I can trun off DVCC, but I will be unable to see and read the batteries 
So I guess the only way to give control back to mppts before shutting down the Raspberry Pi would be to turn off DVCC and reset the VE.Bus ?
Since you use DVCC, the configurations set in the MPPTs doenst matter, it is simply ignored. Thats one of the key points of DVCC, the battery dynamically defines how it wants to be charged, not the settings in the individual devices.
Using DVCC and reading the battery values are two seperate things, but it is recommended to use DVCC with a smart battery.
Removing the controlling device is not a normal or expected thing in DVCC. VenusOS needs to be there in order to coordinate what the battery/its BMS wants with the chargers. You cant just turn it off and go on without. The battery/its BMS needs to have control over charge and discharge.
If your batteries have the ability to disconnect themselves, so they have FETs/IGBTs internally, then you could run the system without DVCC. But if they dont then i would not recommend disabling DVCC.
Up until a couple of days, and for a couple of years, everything was running without the Venus OS part. I install it basically to be able to monitor the system remotely while I am away from the boat.
Then i guess you can turn off DVCC and be in that same config again, but with additional monitoring now