My first headlamp was a Justrite with battery pack holding 4@ D cells. It was US caving's state of the electrical art in 1973. I used it for caving in TAG and, primarily, Florida. In the latter's Redding Catacombs, back when water levels weren't depleted by overpopulation, we pushed 90%-underwater passages by doing duck-unders. I would poke my legs into a submerged passage and, if my feet came up in air, would tied a line to my waist while Brian Houha held the bitter end. Unlike the carbide lamps used by my Luddite grotto-mates, the Justrite worked fine in both air and underwater! At least, the first time I did that it worked. Afterward, the contacts were a little flaky on the bottom of the battery pack, so I soldered the 4@ batteries and battery pack's top contacts together with short copper wires. You can do that with lead-acid D-cell batteries, altho you have to be careful about overheating them.
If the first rule of caving it to know your own limitations, then the second rule is to know your gear's limitations. Earlier cavers didn't survive carbide caps because they were lucky, they survived because they knew themselves and their gear. Read what Ed Hillary and Tenzing Norgay wore on their famous first ascent, and what Jacques Cousteau wore on the world's first cave dive. We wear nylon when we stand on the shoulders of giants that wore herringbone, and our successors will wear caving suits of kevlar/lycra/cordura that look like current snow skiing competition suits.
Cody, remember where I am. I am caving in FL caves so small that I can see twilight a lot of the time and am rarely more than 150ft from an entrance. I carry electric 6 lights with me, plus a cig lighter and a Cyalume, not to mention a Dagwood sandwich, a Sprite in a cold cup, and 2 or 3 Tootsie Pops, the latter number depending on how many buddies are with me. I also carry a bio sampling kit containing a few jiggers of unadulterated ethanol to preserve collected bugs, but which could also be used to fuel a lonely, lost caver.
The lights are a Petzl Myo 3@AA headlamp, an Energizer 3@AAA headlamp, 1@ $20 Princeton Tec 4@AAA flashlight attached to my Petzl Ecrin helmet, 2@ 3@AAA 9-LED $2 flashlights, and a $16 9-LED 3@AAA flashlight. That's a lot of lights and a lot of batteries. Oh, and I carry 4@AAA and 3@AA spare batteries. Oh, and only about a quarter of my caving trips are solo. The caves are phreatic rather than vadose, and we are in a long-term drought so there is very little water in the caves, cave temperatures are in the low 70s, blah blah blah. Also, the $2 flashlights are quite useful and cost-effective for reading the clinometer, compass, FatMax laser 'tape,' and survey book.
As for scaring away other cavers with my cheapo kit, well, I really don't give a flip. I go caving with 3 long-time buddies, and they are comfortable with my FL kit. If caving with $2 flashlights skeers you, you oughta see my FL SRT kit!
But, know ye that I use different kits (plural) when caving in TAG, VA, Belize, Mexico, and Austria. And tadpole, you have a lot to learn about Levi's.
You may stand on my shoulders if you wish.