Seting battery voltage over Ethernet

I have Smart Solar MPPT 100/20 charger connected to Venus OS on RPI 3B over VE.Direct USB. I have connected 24V Battery system about 10m far from the charger. There are big diffrences in Voltage and temperature between battery and charger. For example 4A charging current then voltage differences 0,43V. 10A then voltage differences is about 1V !

I thought about something like Victron Smart Battery Sense and bluetooth connection but it is too far.

So I thought that I can make ESP32 voltage sensor for the battery and then send voltage over Ethernet to the Node Red on Venus OS connected to the charger. But is it posible to set voltage for example in every second in smart solar charger over Node Red or other way?

I tried manually but nothing works I mean when I connect for example using VictronConnect app I see Voltage differences ( for example 0,43V for 4A current)

root@raspberrypi2:~# dbus -y com.victronenergy.solarcharger.ttyUSB0 /Link/VoltageSense SetValue 26.30
root@raspberrypi2:~# dbus -y com.victronenergy.solarcharger.ttyUSB0 /Link/VoltageSense GetValue
value = 26.299999237060547
root@raspberrypi2:~# dbus -y com.victronenergy.solarcharger.ttyUSB0 /Dc/0/Voltage SetValue 26.099996185302739

2 |3000

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matt1309 commented · Mar 28 at 01:17 PM

Hi @Marcin Tomasik

Given the voltage drop is the wire sizing maybe too small?

A lot of people say this suggestion can lead to issues so please research before using but could dvcc shared voltage sense be of any use to you?

11. DVCC - Distributed Voltage and Current Control (victronenergy.com)

In regards to your question my guess is the issue is coming about because you're manually writing to dbus address that is also being written to by the charge controller.

So is it not the case that you're manually writing to dbus address. This dbus address is then being automatically updated when charge controller posts it's sensor data? You'd almost need to disable the charge controller from posting battery voltage data to dbus.

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