On 8/6/2013 4:46 PM, Winston_Smith wrote:
On Tue, 06 Aug 2013 16:13:22 -0400, Nate Nagel wrote:
On 8/6/2013 3:57 PM, Winston_Smith wrote:
I've tried exactly that, a set of D shells that hold AA cells. It
works but the run time is remarkably less. That figures since an AA is
something like 2 Ahr while an alkaline D cell is ten times that or
more.
About five, but yes, valid point.
I stand corrected. I was thinking of 10 Ahr and wrote 10X.
It ought to be possible to put 4x AAs in place of a D cell but there
don't seem to be any commercially available adapters to do this, and
I've had other things to do than to try to make my own (although,
really, it should be fairly easy with some pieces of hardwood dowel, a
drill press, some sheet brass, random bits of hardware, and a little
ingenuity.)
I thought of this too. Even went though the exercise of drawing the
geometry to confirm. I too looked and found nothing commercially. The
only thing I can think of against it is whether the parallel cells
will share.
If you're using Eneloops, and only use cells from one package, they seem
to be "tight" enough that this shouldn't be a problem, although that's a
good thing to think about.
Apparently, in Japan, they sell Eneloop branded C and D cells and
instead of them being purpose built single cells, they are smaller cells
ganged together, which is in essence exactly what we're talking about
doing here.
http://www.candlepowerforums.com/vb/...-Cells-Exposed
So even Sanyo (well, Panasonic now) is confident enough in the
uniformity of their cells that they feel comfortable doing this.
The drawback, of course, is that a "D cell" Eneloop is only 6000 mAh,
using only three cells. I suspect that four is technically outside the
size spec for a D cell but will probably work in most devices. Haven't
bothered to look up the pertinent specs for both to verify. Three is
easily doable, but there doesn't seem to even be a good 3xAA to D cell
adapter readily available. This guy:
http://www.batteryjunction.com/titan...r-adapter.html
will work, but is awful expensive and according to the guys over on
candlepowerforums doesn't have enough metal in it for high current apps.
Of course, these are the same guys that think something like the
DEFT-X is awesome. (google for it) Well, it is, but they're actually
*buying* them. So their idea of "high current" might mean "ludicrous
current" to you and me. I don't know, I haven't purchased those
adapters, as I look at them and think to myself "I can make that." (of
course, because I am physically capable of doing something doesn't
necessarily mean that when it comes to making a choice between making
cell adapters and pouring myself a nice bourbon and sitting on my arse,
I choose to make cell adapters.)
I've even heard that only conductive spacers are needed to make this
work in a Mag-Lite, but haven't tried it other than to confirm that yes,
the cells will fit in the tube.
With some sort of insulation around the outside to keep it from
touching the metal case. Granted the case is anodized and some
anodizing is an insulator but movement and vibration could wear though
that.
Right, but then again it's been a habit of mine for ages to put a piece
of cardboard from a cereal box or whatever in the body of every
flashlight I have to keep the cells from rattling, so that is an easy
inexpensive solution.
One ingenious thought that I heard was to do that, then pick a wood
dowel that would fit in the dead space between two cells, then use that
to line all the cells up. So if you did that then you would really only
need two spacers, and one of them could be e.g. a half dollar or
something like that. The positive end would be the only one where you'd
have to get creative.
Only D-cell mag I have is a four cell light though, so that's $40 worth
of Eneloops, or I'd probably need to gather up every single one around
the house to fill that light. I pretty much keep it out of nostalgia,
as the little single AA Fenix that is in my pocket right now is a better
flashlight, never mind the Surefire 6P with Malkoff drop-in or Fenix
TK41 that I also have. I do open it up every now and then to make sure
that the alkaleaks aren't doing what they do best... I'm trying to
think of another D-cell powered device that I have and can't think of one.
nate