Out of curiosity, what sort of exploration are you doing that you're using 45 cells in one trip?
I'd suspect most caving trips if that's what you're doing would be 1-2 days as I think it would be difficult to carry enough supplies into a cave to last a week, especially if you're crawling through tight spots.
Sorry about derailing the thread a tad bit earlier, but I noticed a few of you were asking about this.
I do professional mineshaft exploration. Except I *used* to use AA/AAA lights. You strap 3 or 4 lights to a helmet and use one or two handhelds and you'll find yourself going through batteries like crazy. When you're a couple hours from anything in the middle of the desert, you gotta take everything you're using for the week.
I don't have that problem anymore. I've switched to rechargeable everything, and alter my Fenix lights to run off rechargeable Li-ion packs in some cases and NiMh for others. Recharging cells off a hobby charger is pretty convenient.
I'm pretty happy with what I've seen of the HP11 after all the reviews about it on here. As I said earlier, my original HP10 is still going strong, so I know Fenix CAN make good headlamps. The HP20 was just not a good design.
All in all the reviews on it here have been great and nicely detailed. Thanks for your guys' input.