Can you stop your Iphone dock charging your phone?

I normally only charge my Iphone 4 when the battery goes into the red because I heard this helps matinee the battery life. I bought an Iphone dock and every time I put my phone on it to play music it charges, is there a way to stop it charging when your playing music?

With modern Lithium Ion batteries like the one in your I phone there's absolutely no need to only chareg when empty. These batteries do not build up a "memory" like the old ones used to. It did used to be the case a few years ago but not now so stop worrying and let it charge away