Concept: MicroROP

[Navck]

Materials -
PR2 Host Body
ROP Bulbs
R123as and a battery holder

Strange idea - What if one were to take R123as and put them in a 4x2 parallel configuration? (You have 4 R123s doing 4.2 volts nominal hooked up to another 4 R123s making 8.4 volts nominal) This could be implemented with 3 or 4 to keep the current draw distributed, thus the protection circuit will not trip. In this configuration, you could probably make a moderately "small" ROP that can do the low bulb, and possibly the high bulb as well. Comparing this to lets say a ROP 2C, this is a very space efficient variant.

 

[DrifT3R]

I think the runtime wouldn't be that great and your flashlight would also be wider than a 2D body.

 

[Nubo]

I got some pretty good output from a 6V bulb (gh24, somewhat comparable to ROP low?), by using 6 high-amp 2/3AA cells -- CBP 750. That battery stack takes up considerably less space than 4AA cells. And the cells can do 10 or even 15 amps. Unfortunately, the host I put it in couldn't handle the heat. But I still think there is some potential with 2/3 AA for a very small form-factor "ROP" light. Drawback is energy density -- only 750mAH cells. But a low version would run long enough for a decent WOW factor, considering the size.

 

[Navck]

Quick calculations - 4x 600MAH = 2400 MAH, which is close enough to having a 18650 if we're talking about R123as with 600 MAH, don't forget the current load will be distributed over several cells, reducing stress per cell. [Well, if you think about it, this is more efficient in storage by using 8 cells in a cylinderical shape vs two very long 18650s in the way the ROP 2C LE is used.]

In this configuration, you might get a short, but fatish shaped flashlight, similar to the Surefire M6 or Microfire HID, but this would be fun for a small, and short ROP.

 

[LumenHound]

I got some pretty good output from a 6V bulb (gh24, somewhat comparable to ROP low?), by using 6 high-amp 2/3AA cells -- CBP 750. That battery stack takes up considerably less space than 4AA cells. And the cells can do 10 or even 15 amps. Unfortunately, the host I put it in couldn't handle the heat. But I still think there is some potential with 2/3 AA for a very small form-factor "ROP" light. Drawback is energy density -- only 750mAH cells. But a low version would run long enough for a decent WOW factor, considering the size.

I like this idea. They would give what, about 20 minutes of runtime on the ROP-LOW bulb?

That could be a nice small stubby ROP-lite if the batteries where set up in a 3 under 3 carrier.

 

[DrifT3R]

Quick calculations - 4x 600MAH = 2400 MAH, which is close enough to having a 18650 if we're talking about R123as with 600 MAH, don't forget the current load will be distributed over several cells, reducing stress per cell. [Well, if you think about it, this is more efficient in storage by using 8 cells in a cylinderical shape vs two very long 18650s in the way the ROP 2C LE is used.]

In this configuration, you might get a short, but fatish shaped flashlight, similar to the Surefire M6 or Microfire HID, but this would be fun for a small, and short ROP.

Well, i would think you could have 2 18650s in series but side by side. That would be quite a small package.

 

[scott.cr]

Well, i would think you could have 2 18650s in series but side by side. That would be quite a small package.

I have made such a light for another CPFer. It was a 2D Maglite host that was cut down to single 18650 length. Inside was a cell holder for two side-by-side 18650s wired in series. Real nice, compact light, and bright!!

Making the light even more compact was a tailswitch configuration. I used one of those pressure-sensitive piezo switches connected to a Hotdriver, so if you didn't actually know where the switch was, it wasn't obvious by a quick visual.