I strongly prefer lights with replaceable cells, but I get why manufacturers do this. It’s weekly if not more that someone posts on reddit about their shiny new D4 not working with some sort of “it flashes once then turns off” or “the battery is too big”, even though it’s an enthusiast light only orderable from two speciality stores and says all over the place what cell to use. Can you imagine a more mainstream brand sold through multiple venues and Amazon? I bet more than half of them would be returned. The alternative would be to at least include a cell - but still. I think sealed cells are awful, but I understand why it’s done on hot rods like this that are just for showing off anyways.