Fortuna Treo 600 Cable for GPS-U2-PS2 – サポートフォーラム

Do I need to connect USB/Car power all the time? [Fortuna Treo 600 Cable for GPS-U2-PS2 - 112534]

I've just got one of these and the Fortuna U2 module. It seems to work fine with the Treo when I have the USB connector plugged in for power. When I remove it to go out cache hunting I seem to lose contact with the GPS. Is this normal? How can I use the device when I am away from a PC or a car lighter socket?