Charging battery too much?

[Confuzzeled23]

Hey everyone,
I have an iPhone 3GS 32 gb that I got about 3 days ago. I have a fm transmitter that charges the phone while transmitting the music through the radio I was wondering if this continual charging through the transmitter is bad for the phones battery? Should I invest in a transmitter that doesn't continually charge the phone? Or does the phone stop recieving charge once it gets to 100 and shows the charged indicator?
Thanks for any replies.

 

[jbennardo]

I heard that this doesn't affect devices with newer batteries. Well I hope it doesn't because thanks to the battery % and OCD I'm a serial charger

 

[-aggie-]

You need to move ions in the battery every once in awhile. So, let it discharge some and don't always keep it charging.