The D cells are mainly for older radios, which work very well. Most of the flashlights run on CR123 or an oddball lithium battery (26650), or simple AAAs. I went to LED years ago on all but a couple of mini Maglites, because the light is brighter and better, and with the ‘monster’ light, I can spot rig signs back off the road out in the boonies (like having another handheld headlight). It can light up all the front yards in a city block from one end, and you don’t want it in your face, even with your eyes closed, but only runs at that level for about 20 minutes before the drain causes it to kick down to a lower light output. I seldom use it for more than 2-3 minutes at a time.
Is your monster light the 26650? Does your charger for that also charge 18650s?
Which light is that?
I think that for security reasons, having an aggressive, powerful flashlight (the type that many here don't know exists) that can dominate your space, your land, and the area under your control and search out nooks and crannies, and identify people and the color of their clothing at 100 and 300 yards away is a powerful boundaries enforcer.
If the grumpy guy with guns and a prepper mentality isn't enough to make a place uninviting, to know that he will put light, brilliant, floody light in the direction of any noise or disturbance on his property line where he can clearly see you and do it while at rifle distances, is a discouragement to pilferers and thieves, and especially sneaky neighbors who could be identified.