I don't understand why you want to keep it in sight. I have the same FFE and my first fobs so dead batteries is worrying thinking about this, if it is in direct sight of the car it uses its transmitter and tries to communicate with the car. So the car and fob play "Marco Polo" continuously 24, 7, 365. It is like the fact my smart phone "in standby" will last a week on a charge but only 10 hours "in use" and I think it is the same for the fob and it's batteries. You understand the car is transmitting "Marco" 24/7 and when one of your fobs hears that WITH the proper ID code it transmits "polo" which is like me surfing the net from my cellphone. A much much more power consuming job than being in "standby" not transmitting at all.