I am new here and not sure if this has been covered before but here is my question. I have a 3D and a 6D Maglite. I purchased a 2 cell extension for the 3D but I am wondering if I can use the extension on the 6D making it an 8D with a 220 lumen cree xp-g2 led bulb that is already installed in the flashlight? Will the extra 3 volts be an issue or should I stick with my original plan and use the extension with the 3D Maglite? If I cannot use that bulb is there a bulb that would be compatible with a 8D Maglite?