me too worried about 10 minute standby limit before connecting it, so I connected my phone to it at the start, but surprisingly mine keeps working even after four hours, without any kind of Bluetooth connection.
FIY: But in my case the GPS keeps feeding Arduino and it is installed with its battery and charging usb connection, in order to do that I soldered the TP4 pad with small piece of Solar Cell tabbing wire.
hope this helps.