My first independent mod! (4D-cell PT Apex)

I decided when I got the Apex that it was a great light with two drawbacks: Primary throw beam wasn't strong enough, and runtime, even on 4AA, wasn't enough. The good people here on CPF had already figured out how to make it brighter, and that was my first non-dropin light mod. But... 4 eneloops will only run so long. Solution? I asked here if anybody knew where I could get a 4-D battery enclosure and they pointed out the Pelican hip-enclosure. I ordered one and discovered when it arrived that it used a mono-headphone jack as a plug. So off to radio shack I went and after some frustration and filing of plastic, here's what I got!



Yep, it works! I'm really pleased, I'm going to take it out for a "test run" soon!:naughty:

Sweet set-up! :goodjob: I am interested in the runtimes you get with your new pack....what are you using for batteries?

Right now just regular energizers because my D NiMH haven't arrived in the mail yet from Thomas Distributing. I got the Powerex 11000mah ones, so I expect them to be pretty good. I don't have a light meter, but I can try to give a ballpark sometime. I'm using eneloops in it w/out the battery pack, so VERY roughly, those have ~ 8000mah total, whereas the Powerex D cells will have ~44000mah total - when they're fully charged of course - so I'd say 5x the runtime would be a pretty reasonable assumption. The one thing I don't like about the Pelican case is that the batteries rattle a bit when they're in there. The Powerex ones might not, but if they do I'm going to put some kind of liner in there to make sure they stay put.

EDIT: Went over to the headlamp forum - the eneloops ran for ~167 minutes, so I'd expect these D cells to run for 800+ minutes! :rock:
EDIT AGAIN: Well, I let it run all afternoon on high using alkalines and after at least 6+ hours on high there is no perceivable decrease in light!

EDIT YET AGAIN: Well, I was using some pretty old D-batteries that were powering two old maglites (one is in the trash, one is holding a P4EverLED and 6 eneloops) so it fell out of regulation after about 7 hours on high. I would guess that you'd probably get 8 hours at least on fresh alkalines, probably more. I can't wait for my Powerex Ds to get here... (tomorrow hopefully!)

Glad the hip pack worked for you!

Toshi

UPDATE:

Did a runtime test with my 4 Powerex D cells today... I charged them up and let them sit for 12 hours and then started the test in the morning. They ran for 856 (that's 14 hours and 16 minutes) minutes on high before the "dropping out of regulation" flashes kicked in and the battery indicator went from green to yellow on the Apex. If experience from the alkalines is any indicator, there's still a reasonable amount of pretty darn bright left, even though it's not regulated anymore - it's still bright as ever according to the official ceiling bounce test. I'd say that's more than reasonable.... in fact, short of SHTF, I can't think of any time where I'd need that much light for that long continuously. I'd definitely recommend this setup to anybody who needs (or wants ) majorly extended runtimes...

If you have a scale handy, it would be appreciated if you could post the total weight of this setup.

Very nice mod! I have had a similar project in mind for my Apex, partly because it's too heavy and I want to get the bulk of the weight off my head and into a pocket, and partly because in cold conditions, batteries will provide better runtimes stored in my pocket than out in the air on the back of my head. Your idea for providing very extended runtimes with drastically larger batteries is pretty cool too. Given the modular nature of your design, it may be worth designing multiple off-head battery packs for different runtime/weight needs. Great job!

Awesome results!! I have the Pro version of the Apex, and I think it would be great if I could have an external battery pack holding a pair of 18650's :naughty:

I weighed the battery pack w/4 NiMH in it plus the light (no batteries, can't have both @ same time the way I did it) and it came out to 2.2lbs. Not too bad, considering, I guess. It sounds heavy to me, but it doesn't feel heavy... That also includes some electrical tape I lined the inside of the batt-pack with - now the cells are snug, can't make 'em rattle even if you want to!