I connected my SB V4600 with my WLAN, logged in into the Zendure App and recognized, that there are two Firmware Updates. One Master Firmware and one AC system Update.
At the second try, the Master Update finished successfully.
The AC Firmware started at the first try, runs to 86%.
But now it doesn't make any further progress.
So, what can I do?
The Battery was loaded by about 40% and was connected to the power