Good plan!

Have you seen these?

http://www.dealextreme.com/p/soshine-2xaa-to-d-size-cell-battery-converter-case-2-pack-7031?item=34

There are several similar designs that accept 3 or 4 AA cells in a D form factor. Even the simple ones for a single AA would allow you to use an AA cell to get your D equipment working (for a shorter time, of course).

Watch out- some designs are series, which means the 3 AA cells are connected together to give 4.5V, which is probably not what you want.

Ahhhh.......Son of a.........

No. I had EDC on the brain and didn't notice the word BOB added in there. (slaps self up side of head)

For a BOB, nothing would beat a good headlamp. Hands down. I have a browning black ice that I cannot kill. I am waiting for it to break so I can get something else but its tougher than hell. Not very bright, but bright enough. The colored LEDs are excellent for hunting (as designed)

Still kinda funny picturing you walk around all day with a headlamp on though.

I use an Apex Pro by Princeton (200 lumen) sans the third strap for my BOB. And a Fenix P3D (205 lumen) for my EDC. Both are CR123 powered so I bought a small box at a heavily discounted $1/ea. - they are Japanese not Chinese branded. I just would like to find a decent carrier for the spares.

I also have a Fenix TK35 in the kitchen drawer.

Naw ... only at night. My wife is never too happy when I'm wearing the headlamp in bed though.

Of course that's the same wonderful wife that gave me a Doug Ritter RSK Mk2 Perseverance for Father's Day!!!

Looking through their specs its a bit of a surprise there's so many settings. But also very nice, I can definitely see myself swaping my "penlight" with an arc or similar for edc.

I was toying with the idea of a headlamp for the house kit, or in the car. Do you find they stay pretty stationary with the battery packs and all?

One other reason i suggested a standard battery is also $$ it seems if you look hard enough you might find some discounted ones.. Which probably means planning ahead.

forgive the pop culture reference, it reminds me of family guy where they lose power and wearing headlamps and peter keeps staring at her boobs.

There are quite a few good, dependable flashlights with variable brightness levels that use standard batteries (AA or AAA). I like a Fenix LD01 on my keychain for EDC. If I had only one light, it would be a headlamp, hands down. ZebraLight has some really neat models, like the 502 - light, bright, and versatile.

ame... my D adapters are a generic single cell spacer type.. my heavier draw tent fans are adapted to a 12v car battery...got a pretty good supply of D cells for the MagLights

freeballer...the Black Diamond has a third strap, with the battery pack in the rear...very solid, though it does weigh more than the cheaper 3 AAA single strap ones... so far, very comfortable, wore it when I was reclaiming a shallow well, for about 4 hours down in the well...I still have a couple of the older AAA Energizers with lithium stashed in the car

For an EDC headlamp take a look at this:

Petzl E94 Zipka 2 Headlamp

It has a unique headstrap that is very small.

REI also carries this.

The Princeton Tec EOS is rock solid on my head. It doesn't really weight that much anyway. No issues with movement or flopping. The up/down angle adjustment has 'stops' to help prevent it from drooping. Works well.

Personally I don't care for headlamps that have secondary battery packs because they become difficult to handle off-head. I want them simple.

I've seen several options for carrying spares.

1 Check out the spare carrier from Surefire. It's heavy plastic with a seal & will hold four batteries. They also make a six cell model
2 A Pelican case with foam
3 Battery Holder
4 Unsealed Case

For times where getting it wet isn't a factor, I'm using options three & four.

When water proof is needed, the spares carriers are more compact but carry fewer cells.