13v+ in a 2D Mag?

[digitaldave]

One of the DIY options I'm considering is Der Wichtel's triple P7 kit, which according to the post needs 13-14v minimum to drive it. I currently have a 2D Mag I would like to put it in. Are there any ways to get the necessary voltage squeezed into a 2D body? I suspect it might be possible using a custom battery pack and a tri or quad bore. So, any way to get 13v or more into a 2D Mag body?

Thanks,

Dave.

 

[Linger]

There is, standard 8AA/2D holder (if labels are turned in, I was able to fit my 8x holder in a new non-bored 2D and a 3D.)
8x14500: 8s, 4.2v*8= 25.6v
4s2p 4,2v*4=16.8v
I just don't recommend it, it's a high draw for 14500 batteries, and your run-time will be crap.
3x26500's (tailcap mod required), make pvc battery tube to keep them from rattling inside, remove tail-cap spring and put a small contact spring leading to -'ve terminal on the bottom of your pvc battery tube. Lots of posts on this mod (3C in M@g 2D) and you could even get decent run-time

**(Edit update- see Benson's post below for a suggestion that 14500's are with-in spec.)

 

[T24]

with mag hosts - everything is possible!

Just 4 example you can squeeze in:

• 4* 18650 (doublebore)
• 15* 2/3a NiMh (tribore)
• 16* 2/3aa NiMh (fits without bore) but only about 600mAh
• 3-6* 17650 (tribore)

Maybe you'll have to drill out tailcap or change stock switch. Just play around witch diameter and length of available rechargables

By the way: Wichtels set is amazing

 

[Benson]

Any number of ways. 2 D cells is 120mm, so you can easily fit 3 2/3A-size cells lengthwise. or 4 if you go into the tailcap. So 6x17500 in a tri-bore would work; 8x14500 in a quad-bore; even 4x18350 single-stack in an unbored light, although not much runtime that way. I believe I've seen 4x18650 in a 2D quad-bore, but I'm not 100% sure on that.

If you prefer NiMH, you'll need 12 cells (well, 11, but you can fit 12 almost any way you can fit 11), so either 12 1/2A in a tri-bore, or 12 2/3AA in a quad-bore.

If you like primaries, I guess you should just be able to fit 6 CR123s in a two-stack arrangement in an unbored light. Never tried that, though.

I haven't investigated discharge rates for any of these, but it shouldn't be an issue for any of them but the 4x18350 (probably need IMR or IFR for those)-- but make sure you do the math before you commit!


EDIT: I see Linger suggests that 8xAA can't take it. Here's my reasoning:

Driver is buck, efficiency presumed to be 80%.
LEDs are P7 in 3s, Vf=3.5V, so V=10.5V I=2.8A, P=29.4W
Power from battery=P/0.8=37W
Power per cell=Pbat/8=4.625W
Current through cell=Pcell/3.7V=1.25A
14500 capacity = 750mA, max safe current=2C/h = 1.5A, we're drawing less, so OK. I guess it might be a bit marginal as the batteries fall to 3V or so and the current correspondingly rises, but still should be OK.

As for 3x26500, I don't know what overhead the Der Wichtel driver has, but I guess when the OP said "13-14V minimum", he didn't mean 12.6V fresh out of the charger and falling off from there would be fine...

 

[T24]

Forget primarys. They dont deliver enough current!

My triple 2D with 15 Nimh drains 1,6A.
I dont know, if 12 cells are enough. Der Wichtels Buckconverter goes to DD, when inputvoltage is too low, so the only issue will be dimming. But thats no target for a triple

 

[digitaldave]

Thanks for the replies everyone. It looks like there's a few options that would work, but whatever way I go it looks like some sort of bore will be needed.

T24, it was seeing your 2D triple P7 that got me thinking in the first place . What would be ideal would be a 15 2/3A battery pack with a connector on the end so just plug and play . 4x18650 in a dual bore might also be good, does anyone know if there are any adaptors available for this setup?

Dave.

 

[malojie]

im running der witchels kit in i guess you could call it a 1.5D mag, bored for fm 4X14670 holder (boring and grooving by will quiles, great job:twothumbs)
its running just fine in it, pulling about 1.9 amps on high, ive not done any runtime as such because been using it on all levels, but it can be still run on a lower power and still get decent ouput, and just use higher power for bursts or to impress with this small size