I don't know which power cord to use on my drill. I have a few and don't know which to use. The one I think is compatible doesn't say B&D on it but has "plug- in power supply for use with drill motor" on the back. It has a standard push pin type of end, yet I can't find the input point on the battery. Do I have the right battery charger for this drill? If so, where's the plug-in on the battery?