My Hardware is 2x Axpert Max 7.2 (firmware U1 45.12/U2 12.21)

I use a diybms with RS485 patch as a Pyltontech emulator. I have AC-In connected, so "utility" is available and is also used by the Axpert when I switch it over.

The BMS controls the charge controller in the Axpert as expected.

I have a question about the inverter settings.

According to the mqtt of "Solar Assistant" the following values are set.

• to_grid_battery_capacity = 10%
• to_grid_battery_voltage = 48 (don't remember setting that)
• device_mode = solar/battery (SBU)
• charger_source_priority Solar first

Do I understand correctly that the Axpert should switch to “Utility” below 10% SOC? Because he doesn't do it, but that's what I would have expected 🙂

What am I doing wrong?

Edited September 14, 20232 yr by Andy_the_German

Since the topic is very interesting to me, I "played" a little 🙂

With Home Assistant I can set the value "to_grid_battery_voltage" and it seems to be adopted.

I have now set 50v but does that change the behavior?

This is a purely voltage based machine for the SoC values to make sense to it via solar assistant the voltage settings must be inline so that the switching at SoC can take place otherwise it will ignore the SoC. Funny enough Voltronics has a new Firmware that will have an SoC function for this instead of voltage settings when you select a BMS in Option 5 eg. PLY, Lib etc. 

The New OG10 or Max 2 in some markets already has this firmware update. It has SoC for switching... regardless of Solar assistant. 

56.07 firmware on the OG10 has it. Probably.ore to follow on the OG7.2 at some stage. 

Edited September 15, 20232 yr by Steve87

yes, it looks like that to me too. So the inverter should normally switch to utility at 10% soc?

I

Does it make sense to use BMS emulation mode?

Edited September 15, 20232 yr by Andy_the_German