(After a few months)
I finally add a udev rule to set it definitly. the gain is greater than the (battery) pain.
Edit /etc/udev/rules.d/99-usb-modem-always-on.rules , add this line:
ACTION=="add", SUBSYSTEM=="usb", ATTR{idVendor}=="2020", ATTR{idProduct}=="2060", TEST=="power/control", ATTR{power/control}="on"