battery help in 2c mag mod

Ok so I've done the 2c mag mod running on three cr123 with the KPR 112 bulb. throw is great but I don't like having to feed it with 3 cr123 all the time. Is there a rechargeable option for this setup? I've read about the ROP/LE setup and it sounds great the only problem is the use of unprotected cells. I was hopeing to feed my mag 2c with protected cells of some sort to lower the boom risk factor. So any help on feeding the 2c kpr 112 with rechargeble's would be great.

Cheers
RM

This is also something I was looking into.

It may be possible to use 2 Pilas 150S or 150A - i believe they are protected cells.

Alternatively, you can use 2 protected 750 mAh RCR123s from Dae together with a dummy 123 cell. I tried this option but the magnets I was planning to use as a dummy cell didn't seem to work so I may have to get a dummy cell from Surefire.

Both options should give 8.2-8.4V fresh off the charger which should be sufficient to drive the KPR 112.

In a 2D Mag, I use 8 NiMH in the 8AA to 2D Willie Hunt/Skip Logan adaptor from Modamag with a KPR118 bulb. That combo is good for about 150 lumens with about a 2 hour runtime. It's a bright and practical flashlight.

The smaller size of a 2C Mag is appealing, but I would much rather not stuff 3 CR123s at a time in it and am also looking for a rechargeable alternative.

The question of dummies comes up often. In one thread, the rolling up of some aluminum foil to the size an AA battery was suggested. I've tried this in a 4AA (4x1 config) Dorcy using 3 AA batts and an aluminum foil dummy with a 3.6V bulb. It worked great! I am certain that the slack in a 2C can also be filled with some aluminum foil rolled and cut or "wadded" to size. Tape around the dummy would probably be needed to prevent shorting.

What is differerence in performance between the 9 volts of the 3 CR123s under the approximately 650mA load of a kpr112 bulb and the 8.4 volts of the protected R123 with the same bulb? What is the runtime and discharge curve for each? Would a 4.8V KPR113 bulb be better with a rechargeable solution?

Of course, any other suggestions would be appreciated.

73
dim

2 of the 168A Pila's fit in the tube in place of 3 123's. Under load, they virtualy deliver the same voltage, 7. 2 nominal, slightly higher when new/fresh charge. The 168A has more capacity than 123's .

NikolaTesla said:

2 of the 168A Pila's fit in the tube in place of 3 123's.

Click to expand...

Don't you mean the Pilas 150As instead? 1 Pilas 168 would be the same height as 2 CR123s.

2 168A's fit inside a Mag 2C with the spring removed and tailcap ground out and just a bit of foil placed in there. They are longer than 150A.s, yes. They have more juice too. Works for hours in here: BAM! multi-level , U bin powered, 360 Lumens at max power , 10,000 Lux:





Or you could put a Carley 1499 bulb in, it pulls like 1500ma, 15,000 Lix

Has anyone tried to use a pair of 3AAA adaptors like those found in 3AAA flashlights? That too should deliver 7.2 nominal volts with, hopefully, insignificant sag as NiMH can deliver the juice. Would they fit? Would resistance be an issue? Would sag be an issue? Any 6AAA adaptors available? Any 4AAA or 8AAA adaptors available? Would they fit? If all is well and good, I'd suspect that six 750mA batts would provide 50-60 minutes of quality runtime to the 650mA draw of a KPR112. Comments?

73
dim

AAA cells last about 15 minites with 650 ma going out of them. Why bother? 18650's can handle 3000 ma without a problem and only cost $6 each. Each one is 4 volts not 1.2.

Nikola -

Regarding 18650s. In light of the sometimes odd behavior of protected cells on incans that's been reported on CPF, having to "prime" the bulb with two ore three flashes before the protection circuit enables current to flow, for the $6 mentioned, are you referring to the unprotected cells from THIS THREAD? If so, do you have any precautionary wisdom on how to best manage unprotected cells during charging and usage?

According to Energizer's DATA SHEET for their latest and greatest NiMH AAA of 850mAh, the discharge curve for the illustrated draws of 850ma (1C) and 425mH (.5C), voltage drops to 1.2V at about 35 minutes and 70 minutes respectively and drops to 1.0V at 1 hour and 2 hours respectively. So I'd expect that the discharge curve for 650mA would fall almost evenly between them. I'd be interested to know if you have any experience to the contrary.

When you say "tailcap ground out", do you mean to scrape enough anodizing off so that the battery and/or the aluminum foil make contact to complete the circuit or to shed a millimeter or two off the cap so that there is extra room for the 18650 batts....or do you mean electrical ground?

73
dim

NT
Thanks for the help. how would 2 pila 150s work in this light? and what would the run time be?

Cheers
Adam