Hello folks, been reading CPF for a while here and there as I've always loved flashlights. However, I dont do many mods to my lights but I'm finally getting around to modding a 3D and 4D Maglite. Main driver for this project is that my Stanley HID runtime just isnt enough when walking around my property.<br><br>I'm aware of all of the AA packs and adapters, but after doing some consideration of both output and runtime, I'm thinking of getting a Magcharger pack made by Powerizer for the 3D. That seems like a simple choice and Terralux themselves have tested it and liked the output when I talked to them on the phone. For the 4D I calculated that seven 1/2 D cell batteries could just barely fit. Four standard D cell are 246mm and seven 1/2 D cell add up to 252mm. I added a 7mm spacer to my 4D and it fit so I'm thinking the seven 1/2 D cells will work. I'm aware of the downsides of D batteries for chargers but I already have one, and was thinking of picking up a Magcharger spare charger that can handle up to six 1/2 D cells, so theoretically I could charge the 1/2 D cells in that stacked. <br><br>Has anyone here tried this approach? Am I missing something important? Last but not least, I'm assuming the Powerizer 1/2 D cells available at 3500 mAh are the same cells they use in their Magcharger 3500 mAh pack. Comments?<br><br>Appreciate the feedback. As an aside, Terralux said the Ministar can handle up to 14V on the phone. Assuming I was talking to someone who knew what they were talking about, that leaves many other options with series/parallel and 3.6V battery packs, but just trying to keep it simple.