Fm Transmitter Battery Is Using An Fm Transmitter To Listen To Your Ipod In The Car Bad?

Is using an fm transmitter to listen to your ipod in the car bad? - fm transmitter battery

I think Griffin FM transmitter for listening to my iPod in my car very frquently. I like it because it performs like my iPod while listening to music. But I've heard that the use of the channel is too bad for the car. Is that true? As the channel used my car battery or something else?