I was just fiddling with my TC-R2, taking it apart, admiring the nice brass threading, checking the battery to see if the switch spring is chewing into the battery casing, etc. And then I dropped the head, getting oil on my shirt. That got me thinking, why are so many flashlights based on the design of a tripartite or bipartite cylinder that has to be disassembled to change the batteries? That would be like having to remove the gas tank from a car in order to fill it, or having to remove the oil pan to change the oil.
One might say that devices which need to be refilled with liquids have an easier time of it, because the liquid can be poured through a small hole, whereas a solid battery has to be removed as a single piece, and that is a fair point; the comparison to filling the gas tank or changing the oil is just the first comparison that came to mind, and is almost certainly not the most accurate. However, flashlights are the only devices I can think of that require the device to be disassembled to replace what is intended to be a modular power source. (nuclear reactors also come to mind, but sadly, I can't snag those at Best Buy yet.)
Yes, some electronic devices have permanently-integrated batteries, but they are different because replacing the battery requires soldering, not just dropping in a new battery once the device is laying in pieces on the workbench. That is not the same paradigm as a device that uses self-contained batteries that maintain electrical connectivity through "casual contact" alone.
Devices that are designed to use replaceable batteries, such as remote controls and Walkmans, generally allow access to the battery via a removable cover that provides no structural support at all, and the device can be operated without the cover if necessary. Whereas, if I need to change the battery in my flashlight in the middle of the woods, I could easily end up dropping and losing a critical piece of the light, rendering it useless.
Assembling the flashlight around the battery, instead of inserting the battery into a fully-assembled flashlight, seems like an outmoded design paradigm left over from when flashlights were simple tin or brass tubes fashioned from household parts, with a bulb and a reflector attached at one end. Given all the innovation that has occurred in the past few years, it seems odd that this one feature has gone un-addressed by almost everyone. Even the Cool Fall SPY, which is the most unconventional flashlight I can think of in every other respect, still integrates an electrical contact into the tailcap, rendering the light useless if the tailcap is lost or the spring somehow falls out.
So I'm curious, why does CPF think this design paradigm has persisted? Is there an overwhelmingly good reason, does nobody care, are there no other feasible ideas, or perhaps all of the above?