Possible to send 'wrong' voltage info over the CANBUS to inverter ?

stuartpittaway / diyBMSv4ESP32

diyBMS v4 code for the ESP32 and new controller hardware

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Possible to send 'wrong' voltage info over the CANBUS to inverter ? #284

Open deekoowee opened 3 months ago

deekoowee commented 3 months ago

My inverter is PylonTech compatible, but its internal software do not accept dynamic charging control. Inverter does not have posibility to change any of the battery details.

I can read the inverter's modbus data and found that it shows the battery voltage and soc CANBUS data from from DiyBMS. I guess, that inverter use canbus voltage and soc to control the charging/discharging.

The inverter work between 48-55,8V. I would like to charge a little more, say 57,4V = more kWh storage. I have 14S13P Leaf battery pack.

I'm not familiar with coding and I don't know, how I should change the code. I wish like to try to cheat the inverter and test this workaround. When real battery voltage is 57,4V, CANBUS send 55,8V. So it is simply deduct 1,6V from all measured voltage and send the cheat voltage data over the canbus.

Any ideas ?

stuartpittaway commented 3 months ago

Hi, unfortunately I don't think it would work - if the inverter can only reach 55.8V, you can't exceed that hardware limitation.

It doesn't appear that the inverter fully supports Pylon protocols - does it support other types of battery?

If you disable "dynamic charge control" then the BMS will ONLY send the voltage value from "battery charge voltage" setting. However, this is likely to lead to cells going over voltage - as normally the dynamic function will reduce the voltage when cells are getting high.

deekoowee commented 3 months ago

I agree, that there might be compatible issue with Pylon protocol. Running now Pylon emulation and selected Freedom Won; Freedom Lite battery. It goes higher (55,8V) than Pylon batteries with Pylon emulator

Supported batteries: BYD; BatteryBox Dyness; Power Box Forsee; Rack 48-3, ZenHome Leclanche; Apollion Cube Pylontech; 3000C, Force L1, Force L2, Phanom-S, US2000, US2000B, US2000B Plus, US2000C, US3000, US5000 UZ Energy; L051100-A Unicorn; EnergyCube 850S Weco; 4K4, 5K3 Yuasa; LIM40E-13, LIM40E-14

stuartpittaway commented 3 months ago

In diybms have you tried setting the inverter to DEYE? Your inverter may have the same problem that one has

deekoowee commented 3 months ago

I'll try that.

deekoowee commented 3 months ago

DEYE setting didn't make any change to top voltage.

stuartpittaway commented 3 months ago

Ok, looks like a limitation of the charger/inverter you are using.