Mod Mag2C for WA1185 / four CR123s

Somebody posted a great mod for a Mag2C, putting 3 CR123s in series, held by automotive tubing, new using a 5-cell Xenon or Krypton bulb from Radio Shack. I loved that mod, very simple and nice and bright.

Recently CPFer larryk mentioned doing the same thing with 3 rechargeable 123s and a WA 1185 bulb. However, there were a number of questions about safety, ie. would the batteries start a fire.

I gathered from reading CPF that primary 123s are less hazardous than rechargeable 123s. (IS THIS CORRECT IN GENERAL?) So I tried to see if I could get four primary 123 lithium batteries in a Mag2C. It turns out that if I remove the spare bulb, and invert the tail cap spring so the smaller rings point towards the tail cap instead or torwards the head, I can JUST BARELY get four 123 batteries in and screw the tail cap shut. I've had trouble reliably completing the circuit with the last battery and spring, because the spring is touching the flat end of the 123. I think if I get a small spring which interlocks with the Mag2c tailcap spring, and points towards the final 123 I can get good contact.

I haven't been able to get it working well enough to compare versus my MagCharger60. It seems to be drawing 2.8A, but this is on 3 Radio Shack and 1 generic 123. I assume if I use higher quality SF batteries I'll get better current and brightness.

Thanks for reading! I hadn't seen this particular mod before, but if it's already been done and perfected, I would certainly appreciate a pointer to the right thread.

Michael

It can't be perfected, because the 123's won't deliver enough current (amperage) to drive the 1185 to its best performance.

Neither 123's or r-123's are designed for that.

Bill

What would be the best bulb for 4 CR123s in a Mag2C?

You have to use a Mag 3 "C" I have tryed several recipes before, the one that works best is WA01318 with 4 123's
or 4 1/2 in a 4 C, (4 1/2 is 4 123/s and a AA lithium)
That works without messing the spring. Now if you want crazy bright put 5 123's WA 01318 and a small coil spring soldered to the stock spring. (run the batteries down for 5 minutes in another light)don't use fresh batteries because you will be running too close to instaflash territory, I know, I did it.
Also with same configuration try Carley 809 potted. very good and bright.
With 4 123's if you don't mind seeing the filament in the beam the Carley 717 is exellent, and it came already potted.
I still have severals 717.
So there you are, WA01318 or the new equivalent, Carley 809
for 4 or five and the 717 that is a tall bulb and if you are picky about beam quality, you can acid etch or sampeper to frost it's glass capsule.
hope it helps
Juan C.

I want to mention one of my favorites, but in a Mag 3 D, it is a double stack of 4 123's running a WA01318, this gave you 57 minutes of crazy bright light.
A little expensive and unnecessary now that we have the Mag 85 with rechargeables in the same format, but a hell of a light!!
Juan C.

[ QUOTE ]
bwaites said:
It can't be perfected, because the 123's won't deliver enough current (amperage) to drive the 1185 to its best performance.

Neither 123's or r-123's are designed for that.

Bill

[/ QUOTE ]

Are you saying that even though I am measuring 2.85A with low-quality 123s, I am unlikely to sustain the rated 3.15A for the WA85 even with Surefire cells? Or that I might achieve the rated current but I'll be damaging the cells or risking fire, etc.?

Thanks, Bill.

I don't think you can get the amperage, first without overheating the cells and risking damage, and second without significantly dropping the voltage.

If you are seeing 2.85 amps, what voltage are you seeing?

My experience is that for every 1 amp draw over 1 amp, you lose 1-2 volts.

Surefire cells are great cells, but they still have essentially the same chemistry, and that chemistry is really only good for 1-2 amps max, and you are asking for nearly double that with the 1185.

Bill