nightsession

I've been thinking to install the newly introduced Nav4All on my cell phone recently, my friend told me it's a very convenient navigation software, it only requires your GPRS cell to have Bluetooth function, so it can be connected with a GPS signal receiver to triangulate your position, utterly simple to maneuver, yet I just don't know, will the excess usage of Bluetooth significantly shorten the life of my battery? How often do I have to recharge? Does anyone here have some hands-on experience about this?