I'm modding a Maglite 6D to use an automotive HID light source. I'm pretty much done, the HID convertor is installed inside, the HID lamp is in the Maglite hood. I would need roughly 12 - 16 Volts of power source. Any tips on using affordable Lithium batteries inside a standard Maglite tube ? The standard 18650 Lithium cells commonly found in laptop batteries do not fit in in pairs. Would prefer to use 4x 3.7 Volt cells. Arno