Sold/Expired Interested in 4x17500 holder?

I contacted mdocod a month ago about 4x17500 holder to fit in 2D unbored M@g. He thought it would be possible since it would follow the same basic layout and end-cap design as his 2x18650>M6 adapter.

4x17500 will provide slightly more Wh than 6 Eneloops: 14.6V * 1100mAh instead of 7.2V * 2000mAh. Slightly more than 1/2 of the capacity but double the voltage allowing boost drivers such as maxFlex2 to drive multi-LED setup harder; at least in burst.

I'm hoping for enough interests for mdocod to build the holder at a reasonable price.

Thanks in for looking
Kurni

And what bulb would we be plugging into the bi-pin holder with 14.6V, and what would the runtime be on AW cells?

Since I know nothing!

I'm an incan noob; I can only rely on what FM said in this thread that WA1132 provides 750 bulb lumens @ 2.2A, which means 2C discharge on AW cells giving 1/2 hour runtime. Overdriven WA1166 provides 900 bulb lumens with regulator @ 2A; less than 2C discharge on AW cells might mean more than 1/2 hour runtime.

Anybody know where I can get such regulator? I've been waiting for AW version but there hasn't been any firm date on when it would be available.

There may be other bulbs; I hope mdocod can chime in regarding the holder and bulb options.

Cheers,
Kurni

Is your goal a 14.8V host, or to maximize Wh in a 2D host?

Wh in 2D host between 10 to 20 V

I'm not sure if it fits, but what about removing the tailcap spring and running 3x 18500? One less cell and higher Wh than 4x 17500. Another option would be 6x RCR123A in a 3s2p holder.

Personally, unless you already have the 2D host you're determined to use, I'd opt for a 3C and 3x AW "C" cells for the extra capacity.

gswitter said:

I'm not sure if it fits, but what about removing the tailcap spring and running 3x 18500? One less cell and higher Wh than 4x 17500. Another option would be 6x RCR123A in a 3s2p holder.

Click to expand...

3 Eneloop fits; I accidentally powered my 7 SSC with 3 Eneloop very briefly. Unfortunately each 18500 is 51.8mm +/-0.5mm; they won't fit.

gswitter said:

Personally, unless you already have the 2D host you're determined to use, I'd opt for a 3C and 3x AW "C" cells for the extra capacity.

Click to expand...

Yes I'm I should have mod a 3C rather than a 2D.

So... anybody interested in 4x17500 holder :wave: ?

Cheers,
Kurni

I've noticed that the AW 17500s are very strong performers for their size, they clock in over 1AH into heavy loads, and over 1.1AH into light loads, very conservatively rated. I haven't seen discharge graphs of AWs 18500, but most 18500s I've seen in Toms li-ion shootout only seem to be around 1200-1300mAH.. if that holds true for AWs, then 4 17500s would have more watt-hours than 3 18500s. Hard to say though, if AWs 18500s hold up to their label capacity, then either configuration would have about the same watt-hour capacity.

For many applications, 3 18500s would be great, if you were willing to push the envelope on li-ion limitations a bit, use it short bursts and charge often, they could be used to drive an 1185 in a 2D host...(this would probably require moving the switch forward, or machining out the tailcap, or both, etc etc)

I think the 4x17500 adapter would find it's "sweet" spot for users who are trying to use something like a maxflex driver to push a bunch of LEDs in series, having higher input voltage improves efficiency of the driver and reduces heat problems at the driver. Would be a good setup for driving 6 LEDs in series. With the output set to 1A the current from the cells would be about 1.7A. ~30-40 minutes runtime and ~1500 emitter lumens.

Another idea- a tri-P7 setup in a 2D (not even sure if parts are available for such a project), buck regulated from 4 li-ion cells would be ideal to keep em in regulation- Could drive at 2.8A with a runtime around 25 minutes. That's 2000+ emitter lumens from a 2D host, not bad.

That's just a few things on my mind that the adapter could be used for, there are certainly other setups in a 2D mag that are competitive, the 4x17500 option really won't open up any doors to a higher level of performance in a 2D host, but may make a few projects more feasible. Sometimes it's fun to just have something a little different

If I see a handful of people interested in this design, I'll give it a whirl, I have to focus on finishing 2x18650 and then 3xAA adapters as planned. This project would be the next on the list if it's worth doing, hehe.

Eric