question

hobohome avatar image

Battery Temperature Sensor Venus VX / SmartSolar

Hi,

In a setup that consists of :

1 X 5kva Muiltiplus

2 X SmartSolar 150/70

1 X BMV 702

1 X Venus GX

1. Can the two SmartSolar charge controllers operate in true parallel (ie both be in the same state)?

2. Can the charging be temperature compensated using the temperature sensor attached to the Multiplus? If not, what do I need to buy to do this?

3. Can the GX publish MQTT topics to my own MQTT broker (Mosquito on another RaspPI)?

4. Can the BMV 702 talk to the GX using a BlueTooth dongle?


Thanks for your help


MPPT - Solar Charge ControllerVenus GX - VGXTemperature SensorMQTT
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4 Answers
wkirby avatar image
wkirby answered ·

1&2. Yes, when operating in networked mode, like ESS, via the Venus GX, the MPPTs act dumb and are instructed by GX. You have to set your charge parameters in the MultipPlus with VE.Configure and the Multiplus will be the master charge controller including temperature compensation if the sensor is connected to it. The MPPTs will follow the charge parameters of the Multiplus.

3. I'm not an expert on MQTT, I think the Venus GX acts as a broker. I'm not sure if two brokers can communicate. Sorry I can't answer, hopefully someone else can clarify.

4. No you cannot use the Bluetooth dongle to connect to the Venus GX. You need to use a VE.Direct cable.

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Thanks very much for the quick and concise answer.

The MQTT thing is not a big deal, I can manage with having two MQTT brokers on the network.

hobohome avatar image
hobohome answered ·

@WKirby, I’m just wondering if you can point me to the documentation that talks about the smartSolar or blueSolar MPPT Controller’s being controlled by the GX/multiplus? I can not seem to find any reference to this function.

Thanks

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wkirby avatar image
wkirby answered ·

It is part of the ESS design manual. This link should take you right to the section where is explains the MPPT's in ESS mode.

https://www.victronenergy.com/live/ess:design-installation-manual#mppt_solar_charger


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Thanks. I did read that, but as we are off-grid, was confused by the paragraph near the top of that page that says...

“When not to use ESS

  • Off-grid systems - either with or without generator.

  • Marine systems.

  • Automotive systems.

  • Inverter priority, also known as 'Intentional islanding“ or 'Ignore AC' input systems.”

wkirby avatar image
wkirby answered ·

Sorry, I did not realise that you were off grid, ESS would not really be suitable for you.
DVCC is more suitable for your system. You can read about it here:

https://www.victronenergy.com/live/ccgx:start?s[]=dvcc#dvcc_-_distributed_voltage_and_current_control

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