Did you ever get a reply on this - second time this happens to me. Exact same issue - first time i had to pay to send out the batteries to be charged . this worked. I managed to get the dongle but not many resources online to figure this out. Also using (2x sVolt batteries and Vito sh8-2k48). I found some reivew for the batteries and i found an interesting line item 'Turns out it was a very silly mistake from my side, the dip switch was not configured properly (I left them all down as per the manual, where dip switch 1 should be in the up position). As soon as we did that, the comms started working' Starting ti think the inverter doesnt communicate with the batteries . Nonetheless - if you had guidance/assistance . please let me know - Avoiding yet another callout