From what I know, when the battery light comes on, that means the battery is not being charged. After running a few tests, I concluded that my alternator was going out.

2004 x5 3.0i.... Only 61k miles before my alternator went out. That was just unbelievable.

Best thing to do is disconnect the power to the angel eyes you installed and see if the battery light still comes on. If it does, then your alternator may be going out or your drive belt may be loose or wearing out. If the light does not come on after disconnecting power to the angel eyes, then it may be related to the way you wired them.