Need Help with SureFire 6P mod.

Hello All,
This is my first post at CandlePower. I been lurking around this forum for many months, and love the useful info here. Thanks to all the posters. <img border="0" title="" alt="[Smile]" src="images/icons/smile.gif" />

I like to modify my SureFire 6P. It's a great light, but as many people know, it only runs about one hour. Ultimately, I like this flashlight to run maybe up to three / four hours.

This is what I like to do. The 6P is a six volt light. It takes two CR123A batteries. SureFire makes an extension tube for the SureFire 6P, that can convert a 6P into a 9P (Nine volt model).

I like to install a couple of these extension tubes to my 6P. I figure I need about six CR123A batteries for three hours of run time. I also need a resistor install, so I don't fry the bulb. The problem is I have no clue what resistor I need to keep it at six volt. I also do not know what "amp" is the SureFire running at. If anyone can help, I will be truly grateful.

Also length of flashlight is not an issue for me. Heck, the longer it is, the better chance to use it as a night stick...heheh <img border="0" title="" alt="[Big Grin]" src="images/icons/grin.gif" />

Thank you in advance.
Warhoggie

I don't think the resistor idea will work for you. Let's say you double the batteries and hence the voltage. To keep the same current running through the lamp you need to add a resistor that will consume the same amount of electricity as your lamp. You therefore lose whatever you hoped to gain by doubling the batteries. What you can do is wire your batteries so that they are in parallel (keeping the lamp at 6V). Problem is you do not have much room to play with inside the barrel. Or you can put together a current (or voltage) regulator but that's another beast altogether.

Unless I am missing something...

Cheers.

Hi Monanza,
Thanks for replying.

I thought a a resistor is designed to limit the flow of electrical current. I am not aware that it consume electrical current as well.

But basically, I have a hollow out dummy battery that i was going to solder a resistor inside of it to keep the flow of electricity at 6 volt. If I can find out what resistor to use, I can at least try to make it work. I may do the same for my SureFire 9P, but with a 9 volt resistor for that model.

The energer that is resisted is converted into heat. So actually it's wasting time, effort, electrcity, money. What you can try and do is have a thin metal foil such that it connects 2 packs of 2 CR123As at both positive and at negative. Something like:

Metal foil 1(+CR123-+CR123-)Metal foil 2 Paper Metal foil 1 (+CR123-+CR123-)Metal foil 2

Don't know if you understand what I mean. Maybe I can get a diagram some time.

Hi Nerd,
thanks for replying.
So what you're saying is that in the process of limiting the flow of electricity, the resistor turns the excess flow into heat, therefore wasting the power from the batteries. I guess that's what Monanza was trying to tell me.

I'm not sure I understand the metal foil method. Can you please elaborate. Also what will happen if the metal foil touches the metal walls of the flashlight?

I guess I trying to find a way to regulate the flow. I mean, LED lights can be regulated, so I was hoping for a way to do the same for the Surefire.

Yes exactly Warhoggie.

I would have suggested the KR2 rechargeable conversion kit but it does not extend runtime (rather it reduces it).

What you need is a battery holder and adapter from Doug Speck (member of this forum). This can either be wide enough for three sets of 2x123 (just like the M6) or it can be thin and long (but thicker than the 6P). Check out the UBH thread for an example of his work.

Cheers.

Because I know nothing about mods, in your situation, i.e. needing three hours of light, I might:

1) carry a 6P (in my case a G2Z) and two sets of spare batteries (saves weight and flashlight bulk), or

2) carry two G2Zs and a set of spare batteries (saves flashlight length, gives redundancy).

he has a good point, get a spares carrier and carry 6 extra 123's and you should be fine.

Whoa! Thanks for all the replies guys. My plan is along the line of what Rifter is saying. I already have the A19s. I think a single CR123A battery puts out 3 Volt @ 1300Mha. But I can't confirm that.

So for 7 cells, that would be like 21 Volt @ 9100Mha? Right? If that is correct, then for my test, all i need to find out is what resistor or IC i need to keep a constant 6 Volt @ 2600Mha, since the 6P is 6 Volts. Then it should work. I have a hollowed out dummy battery already. The hollowed out dummy battery should be able to conduct away some of the heat. I just need to solder the correct components into it. Monanza
earlier seem to imply a voltage regulator may work. I can try that too, but again i need the specs.

I really don't know will it work. But I have the time and I'm bored. Just thought I could do something fun to fill my curiosity.

Warhoggie:

If you don't mind carrying a SF that is five 123 cells long, consider placing 4 @ 43 mm long 4/5 A 2000 mAh NiMH cells in the extended five 123 cell body and drive a AP61 brightly for > 40 minutes. A P6- would run for > 1.5 hours. I'm able to recharge these 4/5 A cells these cells in my Vanson universal smart charger.

Thanks Lemlux,
that sounds ok. But I'm a bit confused. What is a 43mm long 4/5A Cell?

BTW, I moved this thread...
Too much like modding for my liking!

Al

What you could do is say attach 5 A19's for a total space of 7 cells, since you want only 6 cells you could then use the extra space to stick in a voltage/current regulator, should be pretty easy, would need a IC and maybe a resistor or two, how much electronis do you know?. Do you know the voltage/current the lamp you are driving needs?