SMA Sunny Island: Control via Modbus

Hello Guys,

im wondering if someone already got the correct parameters / modbus-registers and usage to control the SMA Sunny Island regarding battery charge etc.

Id like to manually start and stop charging the battery (like during night) via power-grid (when power is cheap) and use it during day.

I know there is a feature in SunnyPortal, but unfortunately SMA isnt able (until today) to solve my issue which is that the connection drops every few minutes. Despite being a local controlled process, the charging of batterie will stop if connection drops… So i like to do it locally.

I already read out values like batterie charge level, some power values… but i dont know what is needed to manipulate the charge process via power-grid.

Many of the SMA Sunny products support SunSpec standard, which greatly simplifies Modbus configuring.

still im not sure which registers and values are needed to switch to manual load and switch back to auto mode…

Any hints?

SunSpec is just for monitoring purposes. It does not cover charging control.

It’s quite a tricky thing to do, it took me quite some days of work to get it to work.

Commercial spoiler warning:
I’m selling an energy management system based on openHAB that can control charging of SMA battery inverters. Tested to work with Sunny Boy Storage, not sure about Sunny Island, but you can download a demo at Die Software-Installation » and try for yourself.

Thanks, i will check

i already found some registers that might be the right ones… like switching to a mode that is supposed to start a full charge. Some other register need to set the desired charging power.

That combined with the registers for current battery charge level would be sufficient for my control. I already got the registers to read out the battery level etc … but im not sure about the control-registers.