Which battery to replace 2x123?

I have two 2x123 lights which I'd like to use more, and would if I had a single-cell option for them. The first is my Quark RGB and the other my incandescent Streamlight Scorpion. If I get a couple 17650's I assume they would work, but don't understand very well how a light that is made for dual cells operates when reduced to a single, larger cell.

Anyone care to weigh in and offer some advice?

It will only work properly if the driver circuit can handle a single cell. Most 2-cell lights are designed to operate on 5-9V, whereas a single rechargeable Li-Ion cell provides 2.8-4.2V, and a single lithium primary provides ~2.8-3.2V. Only a few lights use drivers that can handle both voltage ranges.

If the light you're using is designed for 2 primary cells, then its voltage range is probably 4.5-6.5V, which is still a bit too high to run properly on a single Li-Ion cell, and way too high to run properly on a partly-discharged Li-Ion cell.

The incandescent light most likely doesn't have a driver at all, which means it will just run a lot dimmer than it's supposed to. The Quark may not turn on at all, but if it does, it will probably also be a lot dimmer, and the mode-switching function may not work due to the input voltage being too low.

Some of the incan gurus told me a while ago not to under-drive my direct driven Surefire P60, ROP and 1185. I can't remember the specifics but its bad for the filament and reduces lamp life.

The high voltage Quark head for the reg./tact./turbo series handles 3 to 9 volts I believe. I would think perhaps the RGB would be along the same lines? I use a 17670 in my Surefire G2X with no problems or loss of lumens (as far as I can detect).

Selfbuilt has some great runtime graphs of the Quark RGB with different batteries that you could check out:

http://www.candlepowerforums.com/vb...-Quark-RGB-Review-RUNTIMES-BEAMSHOTS-and-more!

Runtime graphs include CR123, 17670, 18650.

kramer5150 said:

Some of the incan gurus told me a while ago not to under-drive my direct driven Surefire P60, ROP and 1185. I can't remember the specifics but its bad for the filament and reduces lamp life.

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Correct. It's hard on your lamp when you run batteries way down as well.

Thanks for all the great info, even though it's not as positive as I'd hoped for.

ebow86 said:

Correct. It's hard on your lamp when you run batteries way down as well.

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Then possibly I could buy a different bulb that was intended for the lower voltage?

Or You buy a 9V bulb and use two 16340 rechargeables. I've read somewhere that You shouldn't use IMRs for normal bulbs because they deliver too much current.