@plonkster I hear what you are saying, but if the problem is that the driver is not releasing the serial port this would be a problem for all installations.
The run was copied and modify from another driver and is very plain.
#!/bin/sh
exec 2>&1
exec softlimit -d 100000000 -s 1000000 -a 100000000 python /opt/victronenergy/dbus-serialbattery/dbus-serialbattery.py /dev/TTY
Jose had the same problem. The issue was with custom cables that had problematic serial numbers (all the same). The solution was to change the cable serials and names. Or you can swop the cables out with correct cables like the Victron versions.
In this topic below is also an example of how the log looks when it exits correctly.
@lukaswien you might want to read up on how Jose changed the serials and names. Here is the post